METHODS FOR THE DETERMINATION
OF ORGANIC COMPOUNOS IN
' FINISHED DRINKING WATER
ANO RAW SOURCE WATER
September 1986
PHYSICAL ANO CHEMICAL METHOOS BRANCH
ENVIRONMENTAL MONITORING ANO SUPPORT LABORATORY
U. S. ENVIRONMENTAL PROTECTION AGENCY
CINCINNATI, OHIO 45268
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DISCLAIMER
This report has been reviewed by the Environmental Monitoring and
Support Laboratory, U. S. Environmental Protection Agency, and approved for
publication. Mention of trade names or commercial products does, not
constitute endorsement or recommendation for use.
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FOREWORO
Environmental measurements are required to determine the quality of
ambient waters and the character of waste effluents. The Environmental
Monitoring and Support Laboratory - Cincinnati, conducts research to:
o Develop and evaluate techniques to measure the presence and
concentration of physical, chemical, and radiological pollutants 1n
water, wastewater, bottom sediments, and solid waste.
o Investigate methods for the concentration, recovery, and
Identification of viruses, bacteria and other microbiological
organisms 1n water; and to determine the responses of aquatic
organisms to water quality.
° Develop and operate an Agency-wide quality assurance program to
assure standardization and quality control of systems for monitor-
ing water and wastewater.
o Oevelop and operate a computerized system for Instrument automation
leading to Improved data collection, analysis, and quality control.
Under authority of the Safe 0r1nk1ng Water Act and the National Interim
Primary 0r1nk1ng Water Regulations, the U. S. Environmental Protection
Agency establishes test procedures for monitoring contaminants 1n public
water supplies. The test procedures 1n this document are designed to
measure volatile organic compounds 1n such waters prior to or after final
treatment.
Robert I. Booth,. Director
Environmental Monitoring and Support Laboratory
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ABSTRACT
The methods contained in this report describe the requirements for the
analysis of drinking water and raw source water for 53 volatile organic
compounds. The methods were prepared to be used for monitoring for volatile
synthetic organic compounds (VOC) at low concentrations in such matrices, as
proposed in 40 CFR 141.24. The methods may also be used for the proposed
monitoring requirement for unregulated contaminants in 40 CFR 141.40.
Included are sample collection and preservation procedures, Instructions for
preparation of standards, required operating conditions and quality control
requirenents.
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PREFACE
On November 13, 1985, the U.S. Environmental Protection Agency published
(SO R 46902) proposed National Drinking Water Regulations for eight vola-
tile synthetic organic chemicals (VQCsJ and proposed monitoring requirements
for these eight VOCs, tetrachloraethene and 51 other volatile compounds.
Three methods in this report (Methods 502.1, 503.1, and 524.1) were proposed
for use for the regulated contaminants and 1n conjunction with Method 504,
for the proposed monitoring requirement.
The Agency 1s committed to avoid the needless proliferation of methods,
however, the evolution of measurement technology and the timing of regula-
tory actions have resulted in a number of similar methods. To avoid
confusion, the following discussion of the relationship of these methods to
previous editions 1s provided.
Method 502.1 is the third generation method for volatile organohal1des.
It was produced originally as Method 501.1 for the measurement of total
trlhalomethanes as defined and required In 40 CFR Part 141.30. It was
incorporated into 40 CFR Part 141.30 on November 29, 1979. The method was
extended and formatted to its current broad scope as Method 502.1 in April
1981 and made available by the Environmental Monitoring and Support
Laboratory - Cincinnati (EMSL-Cincinnati) to support the reconvnended maximum
contaminant levels (RMCLs) for VOCs proposed on June 12, 1984. This current
edition, which replaces the 1981 version of 502.1, focuses on the specific
analytes 1n the YOC JCl. and the monitoring proposals. The major changes 1n
the method, reflected In this version, Include a strictly prescribed
preservation procedure and a maximum holding time for samples. The quality
control requirements were modified in 1986 to reflect public comments on the
November 1985 proposed rule, and two analytes were removed from the scope of
the method. Although the Agency has not at this time proposed the method
for approval in Part 141.30, such a proposal is under consideration.
Method 503.1 1s a revision of the method prepared-1n April 1981 and made
available by EM5l-C1nc1nnat1 to support the RMCL proposal for VOCs. The
current revision, which replaces the 1981 version, focuses on the specific
analytes in the VOC MCI and monitoring proposals and establishes preserva-
tion procedure and maximum holding time for the samples. It, too, has been
revised to reflect public comments.
Method 504 was developed to measure low concentrations of
l,2-d1bromoethane (EDB) and l,2-dibromo-3-chloropropane (OBCP). Method
524.1 is a version of the general GC/MS procedure for volatlles described in
Method 524 in February 1983, and subsequently approved for trlhalomethane
measurements. The principal changes Incorporated in this method include a
focus on the specific analytes in the VOC MCL and monitoring requirement and
establishes the preservation procedure and maximum holding time for
samples. The quality control section of the method has been revised to
reflect public caimtent and the scope of the method has been reduced to
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reflect the limitations of packed-column gas chromatography as defined by
conventional practices. Although the Agency has not, at this time, proposed
the method for approval in Part 141.30, such a proposal is under
consideration.
Method 524.2 is introduced for the first time in this edition. It was
developed in direct response to connents on the proposed rules. By
approving capillary column techniques as described in this method, the
Agency will be recognizing recently achieved technological advances in
chromatography that permit separations to be achieved more completely and
more rapidly and, thus, at lower cost than those established at the time of
proposed rulemaking.
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CONTENTS
Paae
Disclaimer 11
Foreword 111
Abstract 1v
Preface
Acknow 1 edgements v111
Method 502.1 - Volatile Halogenated Organic Compounds
1n Water by Purge and Trap Gas Chromatography
Method 503.1 - Volatile.Aromatic and Unsaturated Organic
Compounds In Water by Purge and Trap Gas Chromatography
Method 504 - 1,2-01bromoethane (ED8) and
lt2-01brorao-3-chloropropane (08CP) 1n Water by
M1croextract1on and Gas Chromatography
Method 524.1 - Volatile Organic Compounds 1n Water by
Purge and Trap Gas Chromatography/Mass Spectrometry
Method 524.2 - Volatile Organic Compounds 1n Water by Purge and Trap
Capillary Column 6as Chromatography/Mass Spectrometry
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ACKNOWLEDGMENTS
The methods in this document reflect public comments received on the
November 1985 edition proposed on November 13, 1985 to support regulations
for the U. S. Environmental Protection Agency's (USEPA) Office of Orlnking
Water (50 FR 46902). The revisions Include one new method (Method 524.2)
based upon work by Robert W. Slater, Jr. and Carol A. Madding. The
remaining methods have been revised under the direction of an ad-hoc USEPA
Work Group composed of the following: James J. Llchtenberg, James E.
Longbottom, William L. Budde, Robert L. Graves, Robert W. Slater, Jr.,
Thomas A. Bellar, Ann A1ford-Stevens, and Raymond J. Wesselman, of the
Environmental Monitoring and Support Laboratory - Cincinnati; Herbert J.
8rass, Robert F. Thomas, David J. Munch, Carol A. Madding, and Kent Sorrel!
of the Technical Support Division, Office of Drinking Water; and Alan A.
Stevens of the Water Engineering Research Laboratory - Cincinnati.
The methods proposed in November 1985, were prepared by the staff of the
Environmental Monitoring and Support Laboratory - Cincinnati
(EMSL-C1ncinnat1) with the support and cooperation of the Office of Orlnking
Water, U. S. Environmental Protection Agency, Washington, 0. C. Special
acknowledgments are due for technical contributions during the preparation
of these procedures to the staffs of the Technical Support Division, Office
of Drinking Water, and of the Water Engineering Research Laboratory, Office
of Research and Development, Cincinnati, Ohio. James E. Longbottom was
responsible for preparing the combined methods package which was based upon
earlier versions of Methods 502.1, 503.1 developed by Thomas A. Bellar, and
Method 524 developed by Ann A1ford-Stevens, James W. Eichelberger, and
William L. Budde. Method 504 was prepared based upon the work of Theodore W.
W1nf1eld and Arnold L. Cohen. Data to support sample preservation and
holding times were developed by Thomas A. Bellar, Robert W. Slater, Jr., and
Kent Sorrel!.
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METHOD 502.1. VOLATILE HALOGENATED ORGANIC COMPOUNDS
IN WATER BY PURGE ANO TRAP GAS CHROMATOGRAPHY
(1985, Ed. Rev. 1986)
1. SCOPE AND APPLICATION
1.1 This method 1s applicable for the determination of various
halogenated volatile compounds in finished drinking water, raw
source water, or drinking water in any treatment stage. (1) The
following compounds can be determined by this method:
Analyte
CAS No.
Bromobenzene
108-86-1
Bromoch 1 oromethane
74-97-5
Bromodi ch 1 orome thane
75-27-4
Bromofonn
75-25-2
Bromomethane
74-83-9
Carbon tetrachloride
56-23-5
Chlorobenzene
108-90-7
Chloroethane
75-00-3
Chloroform
67—66—3
Chioromethane
74-87-3
2-Chlorotoluene
95-49-8
4-Chlorotoluene
106-43-4
01bromoch1oromethane
124-48-1
1,2-01bromoethane
106-93-4
01 bromomethane
74-95-3
1,2-01ch1orobenzene
95-50-1
1,3-01ch1orobenzene
541-73-1
1,4-01ch1orobenzene
106-46-7
01ch1orodif1uoromethane
75-71-8
1,1-01ch1oroethane
75-34-3
1,2-01ch1oroethane
107-06-2
1,1-01chloroethene
75-35-4
c1 s-1,2-01ch1oroethene
156-59-2
tr ans-1,2-01ch1oroethene
156-60-5
1,2-01ch1oropropane
78-87-5
1,3-01chloropropane
142-28-9
2,2-01chloropropane
590-20-7
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Analyte
CAS No.
1,1-01ch1oropropene
563-58-6
Methylene chloride
75-09-2
1,1,1,2-Tet rach1o roethane
630-20-6
1,1,2,2-Tetr ach1oroethane
79-34-3
Tetrachloroethene
127-18-4
1,1,1-Trich1oroethane
71-55-6
1,1,2-Trfchloroethane
79-00-5
Trlchloroethene
79-01-6
Trichlorofluorcmethane
75-69-4
1,2,3-Tr1ch1oropropane
96-18-4
Vinyl chloride
75-01-4
1.2 Single laboratory accuracy and precision data show that this
procedure 1s useful for the detection and measurement of
multi-component mixtures spiked Into carton filtered finished water
and raw source water at concentrations between 0.20 and 0.40 Wg/L
wlth method detection limits (MOL) (2) generally less than
0.01 ug/L. Method detection limits for several of the listed
analytes are presented in Table 1 (1). Some laboratories may not
be able to achieve these detection limits since results are
dependent upon instrument sensitivity and matrix effects.
Determination of complex mixtures containing partially resolved
compounds may be hampered by concentration differences larger than
a factor of 10. This problem connonly occurs when finished
drinking waters are analyzed because of the relatively high
trlhalomethane content. When such samples are analyzed, chloroform
will affect the method detection limit for 1,2-dlchloroethane.
1.3 Based upon similarities 1n structure with other analytes in the
scope, 2,2-d1chloropropane was Included in the November 13, 198S
proposed monitoring regulation although supporting accuracy and
precision data are not yet available for inclusion in this method.
1.4 This method 1s recommended for use only by analysts experienced 1n
the measurement of purgeable organlcs at the low ug/l level or by
experienced technicians under the close supervision of a qualified
analyst. It Is also recommended for use only with a purge and trap
system devoted to the analysis of low level samples.
2. SUMMARY OF METHOD
2.1 Organohalldes and other highly volatile organic compounds with low
water solubility are extracted (purged) from the sample matrix by
bubbling an inert gas through the aqueous sample. Purged sample
components are trapped in a tube containing suitable sortsent
materials. When purging is complete, the sorbent tube is heated
and backflushed with an inert gas to desorb trapped samole
components onto a gas chromatography (GC) column. The gas
c.--omatograph is temperature orograimed to separate the method
analytes which are then detected with a halogen specific detector.
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2.2 A second chromatographic column is described that can be used to
confirm SC Identifications and measurements. Alternatively,
confirmatory analyses may be performed by gas chromatagraphy/mass-
spectrometry (GC/MS) according to Method 524.1 or Method 524.2 if
sufficient material is present.
3. INTERFERENCES
3.1 During analysis, major contaminant sources are volatile materials
1n the laboratory and Impurities In the inert purging gas and 1n
the sorbent trap. The use of non-polytetrafluoroethylene (PTFE)
plastic tubing, non-PTFE thread sealants, or flow controllers with
rubber components in the purging device should be avoided since
such materials out-gas organic compounds which will be concentrated
1n the trap during the purge operation. Analyses of laboratory
reagent blanks (Sect. 9.1.3) provide Information about the presence
of contaminants. When potential Interfering peaks are noted 1n
laboratory reagent blanks, the analyst must eliminate the problem
before analyzing samples. Subtracting blank values from sample
results 1s not permitted.
3.2 Interfering contamination may occur when a sample containing low
concentrations of volatile organic compounds is analyzed
immediately after a sample containing relatively high
concentrations of volatile organic compounds. A preventive
technique is between-sample rinsing of the purging apparatus and
sample syringes with two portions of reagent water. After analysis
of a sample containing high concentrations of volatile organic
compounds, laboratory reagent blanks must be analyzed until system
memory Is reduced to an acceptable level.
3.3 Special precautions must be taken to analyze for methylene
chloride. The analytical and sample storage area should be
isolated from all atmospheric sources of methylene chloride,
otherwise random background levels will result. Since methylene
chloride will permeate through PTFE tubing, all gas chromatography
carrier gas lines and purge gas plumbing should be constructed from
stainless steel or copper tubing. Laboratory clothing worn by the
analyst should be clean since clothing previously exposed to
methylene chloride fumes during coumon I1
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a potential health hazard, and exposure to these chemicals should
be minimized. Each laboratory 1s responsible for maintaining •
awareness of OSHA regulations regarding safe handling of chemicals,
used in this method. Additional references to laboratory safety
are available (3-5) for the information of the analyst.
4.2 The following method analytes have been tentatively classified as
known or suspected human or mamnalian carcinogens: carton
tetrachloride, l,2-d1chloroethane, 1,1,2,2-tetrachloroethane,
1,1,2-trichloroethane, chloroform, l,2-d1bromoethane,
tetrachloroethene, trlchloroethene, and vinyl chloride. Pure
standard materials and stock standard solutions of these compounds
should be handled 1n a hood. A NIOSH/MESA approved toxic gas
respirator should be worn when the analyst handles high
concentrations of these toxic compounds.
5. APPARATUS AND EQUIPMENT
5.1 SAMPLE CONTAINERS - 40-ni to 120-
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to be analyzed, both the silica gel and charcoal can be
eliminated and the polymer increased to fill the entire
trap. Before Initial use, the trap should be conditioned
overnight at 130*C by bacJcflushing with an inert gas flow of
at least 20 mL/tnin Vent the trap effluent to the room, not
to the analytical column. Prior to daily use, the trap
should be conditioned for 10 minutes at 1SG*C with
backflushirrg. The trap may be vented to the analytical
column during daily conditioning; however, the coTumn must
be run through the temperature program prior to analysis of
samples.
5.2.3 The^desorber must be capable of rapidly heating the trap to
180*0. The polymer section of the trap should not be heated
higher than 200 C or the life expectancy of the trap will
decrease. Trap failure is characterized by a pressure drop
in excess of 3 pounds per square inch across the trap during
purging or by poor brcmoform sensitivities. The desorber
design illustrated in Figure 2 meets these criteria.
5.2.4 Figures 3 and 4 show typical flow patterns for the
purge-sorb and desert mode.
GAS CHROMATOGRAPHY SYSTEM
5.3.1 The SC must be capable of temperature programming and should
be equipped with variable-constant differential flow
controllers so that the column flow rate will remain
constant throughout desorptlon and temperature program
operation. The column oven may need to be cooled to <30*C
(Sect. 10.3)i therefore, a subambient oven controller may be
required.
5.3.2 Two gas chromatography columns are recottmended. Column 1 is
a highly efficient column that provides outstanding
separations for a wide variety of organic compounds. Column
1 should be used as the primary analytical column unless
routinely occurring analytes are not adequately resolved.
Colwm 2 1s recommended for use as a confirmatory column
when GC/MS confirmation is not available. Retention times
for the listed analytes on the two columns are presented 1n
Table 1.
5.3.2.1 Column 1 - 1.5 to 2.S m x 0.1 in 10 stainless steel
or glass, packed with 13J SP-1000 on Ccrtopack-8
(60/80 mesh) or equivalent. The flow rate of the
helium carrier gas 1s established at 4€ mL/rain. The
column temperature is programmed to hold at 45*C for
three min, Increased to 220*C at 3"C/min, and held
at 220*C for 15 min or until all expected compounds
have eluted. During handling, packing, and
programing, active sites can be exposed an the
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Carbopack-3 packing which can result in tailing peak
geometry and poor resolution of many constituents.
To protect the analytical column, pack the first 5"
cn of the column with 35 SP-1000 on Chrcmosorb-y
(60/30 mesh) followed by the Carbopack-3 packing.
Condition the precolumn and the Carbopack columns
with carrier gas flow at 220#C overnight. Pneumatic
shocks and rough treatment of packed columns will
cause excessive fracturing of the Carbopack. If
pressure in excess of 60 psi is required to obtain
40 nL/m1n carrier flow, the column should be
repacked. A sample chromatogram obtained with
Column 1 is presented in Figure 5.
5.3.2.2 Column 2 - 1.5 to 2.5 m long x 0.1 1n 10 stainless
steel or glass, packed with n-octane chemically
bonded on Por1s11-C (100/120 mesh) or equivalent.
The flow rate of the helium carrier gas 1s
established at 40 raL/nrln. The column temperature 1s
programed to hold at 50 *C for three m1n, Increased
to 170*C at 6*C/m1n, and held at 170"C for four min
or until all expected compounds have eluted.
5.3.3 An electrolytic conductivity or nrlcrocoulometric detector 1s
required. These halogen-specif1c systems eliminate
nrls1dent1f1cat1ons due to non-organohal1des which are
coextracted during the purge step. A Tracor Hall Model
700-A detector was used to gather the single laboratory
accuracy and precision data shown in Tables 2 and 3. The
operating conditions used to collect these data are as
follow:
5.3.4 It is acceptableto Insert a photo Ionization detector
between the analytical column and the hallde detector to
simultaneously analyze for the regulated volatile organic
compounds (VOC) that are aromatic or unsaturated (6). Most
of the anaiytes listed in the Scope of Method 503.1 can be
determined 1n this manner.
SYRINGE ANO SYRINGE VALVES
5.4.1 Two 5-mL glass hypodermic syringes with Luer-Lok tip.
Reactor tube:
Reactor temperature:
Reactor base temperature:
Electrolyte:
Electrolyte flow rate:
Reaction gas:
Carrier gas:
Nickel 1/16 1n 00
810*C
250*C
1003! n-propyl alcohol
0.8 mL/min
Hydrogen at 40mL/min
Helium at 40 mL/min
5.4.2 Three 2-way syringe valves with Luer ends.
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5.4.3 One 25-uL micro syringe with a 2 in * Q.006 In ID, 22" bevel
needle (Hamilton #702N or equivalent).
5.4.4 Micro syringes - 10, 100 »L.
5.4.5 Syringes - 0.5, 1.0, and 5-mL, gas tight with shut-off valve.
5.5 MISCELLANEOUS
5.5.1 Standard solution storage containers - 15-mL bottles with
PTFE-lined screw caps.
6. REAGENTS ANO CONSUMABLE MATERIALS
6.1 TRAP PACKING MATERIALS
6.1.1 2,6-01 phenylene oxide polymer, 60/80 mesh, chromatographic
grade (Tenax fiC or equivalent).
6.1.2 Methyl silicone packing - OV-1 (3S) on Chromosorb-W, 60/80
mesh or equivalent.
6.1.3 Silica gel - 35/60 mesh, Davison, grade 15 or equivalent.
6.1.4 Coconut charcoal - Prepare from 8amebey Cheney, CA-580-26
lot #M-2649 by crushing through 26 mesh screen.
6.2 COLUMN PACKING MATERIALS
6.2.1 IS SP-1000 on 60/80 mesh Carbopack-8 or equivalent.
6.2.2 n-Octane chemically bonded on Porasil-C, 100/120 mesh
(Durapak or equivalent).
6.2.3 3S SP-1000 on 60/80 mesh Chromosorb-W or equivalent.
6.3 REAGENTS
6.3.1 Methanol - demonstrated to be free of analytes.
6.3.2 Reagent water - Prepare reagent water by passing tap water
through a filter bed containing about 0.5 leg of activated
carton, by using a water purification system, or by boiling
distilled water for 15 min followed by a 1-h purge with
Inert gas while the water temperature Is held at 90*C.
Store 1n clean, narrow-mouth bottles with PTFE-lined septa
and screw caps.
6.3.3 Hydrochloric acid (1*1) - Carefully add measured volume of
conc. HC1 to equal volume of reagent water.
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6.3.4 Vinyl chloride - 99.92 pure vinyl chloride is available from
Ideal Sas Products, Inc., Edison, Ne* Jersey and from
Mathescn, East Rutherford, lew Jersey. Certified mixtures
of vinyl chloride 1n nitrogen at 1.0 and 10.0 ppm are
available from several sources.
6.4 STANOARQ STOCK SOLUTIONS - These solutions may be purchased as
certified solutions or prepared from pure standard materials using
the following procedures:
6.4.1 Place about 9.8 WL of methanol into a 10-
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7. SAMPLE COLLECTION, PRESERVATION, AND STORAGE
7.1 SAMPLE COLLECTION
7.1.1 Collect all samoles in duplicate. Fill sample bottles to
overflowing. No air bubbles should pass through the sample
as the bottle is filled, or be trapped in the sample when
the bottle is sealed.
7.1.2 When sampling from a water tap, open the tap and allow the
system to flush until the water temperature has stabilized
(usually about 10 min). Adjust the flow to about 500 mL/min
and collect duplicate samples from the flowing stream.
7.1.3 When sampling from an open body of water, fill a 1-quart
wide-mouth bottle or 1-liter beaker with sample from a
representative area, and carefully fill duplicate sample
bottles from the 1-quart container.
7.2 SAMPLE PRESERVATION
7.2.1 Adjust the pH of the duplicate samples <2 by carefully
adding one drop of 1:1 HC1 for each 20 mL of sample
volume.(7) Seal the sample bottles, PFTE-face down, and
shake vigorously for one minute.
7.2.2 The samples must be chilled to 4*C on the day of collection
and maintained at that temperature until analysis. Field
samples that will not be received at the laboratory on the
day of collection must be packaged for shipment#w1th
sufficient ice to ensure that they will be at 4*C on arrival
at the laboratory.
7.3 SAMPLE STORAGE
7.3.1 Store samples at 4*C until analysis. The sample storage
area must be free of organic solvent vapors.
7.3.2 Analyze all samples within 14 days of collection. Samples
not analyzed within this period must be discarded and
replaced.
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8. calibration ano standardization
3.1 CALIBRATION
8.1.1 A set of at least five calibration standards containing the
method analytes is needed. More than one set of calibration
standards may be required. One calibration standard should
contain each analyte at a concentration approaching but
greater than the method detection limit (Table 1) for that
compound; the other standards should contain analytes at
concentrations that define the range of the method.
8.1.2 To prepare a calibration standard, add an appropriate volume
of a secondary dilution standard solution to an aliquot of
reagent water in a volumetric container or sample syringe.
Use a mlcrosyringe and rapidly Inject the alcoholic standard
into the water. Remove the needle as quickly as possible
after Injection. Aqueous standards are not stable and
should be discarded after one hour unless sealed and stored
as described in Sect. 7.2.2.
8.1.3 Starting with the standard of lowest concentration, analyze
each calibration standard according to Sect. 10 and tabulate
peak height or area response versus the concentration 1n the
standard. The results can be used to prepare a calibration
curve for each compound. Alternatively, 1f the ratio of
response to concentration (calibration factor) 1s a constant
over the working range (<102 relative standard deviation),
linearity through the origin can be assumed and the average
ratio or calibration factor can be used 1n place of a
calibration curve.
8.1.4 The working calibration curve or calibration factor must be
verified on each working day by the measurement of one or
more calibration standards. If the response for any analyte
varies from the predicted response by more than *20S, the
test must be repeated using a fresh calibration standard.
If the results still do not agree, generate a new
calibration curve or use a single point calibration standard
as described 1n Sect. 8.1.5.
8.1.5 Single point calibration 1s a viable alternative to a
calibration curve. Prepare single point standards from the
secondary dilution standards 1n methanol. The single point
standards should be prepared at a concentration that
produces a response close (±20S) to that of the unknowns.
8.1.6 As a second alternative to a calibration curve, internal
standard calibration techniques may be used. The following
organohal1des are reconmended for this purpose:
2-bromo-l-chloropropane or 1,4-dichlorobutane. The internal
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standard is added to the sample just before purging. Check
the validity of the internal standard calibration factors
daily by analyzing a calibration standard.
8.1.7 Calibration for vinyl chloride using a certified gaseous
mixture of vinyl chloride in nitrogen can be accomplished by
the following steps.
8.1.7.1 Fill the purging device with 5.0 mL of reagent water
or aqueous calibration standard.
8.1.7.2 Start to purge the aqueous mixture. Inject a known
volume (between 100 and 2000 uL) of the calibration
gas (at room temperature) directly Into the purging
device with a gas tight syringe. Slowly inject the
gaseous sample through a septum seal at the top of
the purging device at 2000 uL/min. Oo not Inject
the standard through the aqueous sample Inlet
needle. Inject the gaseous standard before five min
of the ll-m1n purge time have elapsed.
8.1.7.3 Determine the aqueous e Concentration of gaseous standard in ppm
(v/v);
V m Volume of standard Injected 1n milli-
liters.
INSTRUMENT PERFORMANCE - Check the performance of the entire
analytical system dally using data gathered from analyses of
reagent blanks, standards, duplicate samples, and the quality
control check standard (Sect. 9.3.1).
8.2.1 All of the peaks contained 1n the standard chromatograms
must be sharp and symmetrical. Peak tailing significantly
1n excess of that shown 1n the method chromatogram
(Figure 5) must be corrected. Tailing problems are
generally traceable to active sites on the SC column or the
detector operation. If only the compounds eluting before
chloroform give random responses or unusually wide peak
widths, are poorly resolved, or are missing, the problem 1s
usually traceable to the trap/desorber. If only brominated
compounds show poor peak geometry or do not properly respond
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at low concentrations, repack the trap. Excessive detector
reactor temoeratures can also cause low bromofora response.
If negative peaks appear 1n the chromatogram, replace the
1on exchange column and replace the electrolyte in the
detector.
8.2.2 Check the precision between replicate analyses. A properly
operating system should perform with an average relative
standard deviation of less than 10*. Poor precision is
generally traceable to pneumatic leaks, especially around
the sample purger and detector reactor inlet and exit,
electronic problems, or sampling and storage problems.
Monitor the retention times for each organohaliae using data
generated from calibration standards and the laboratory
control standard. If individual retention times vary by
more than 10X over an 8-h period or do not fall within 10S
of an established norm, the source of retention data
variance must be corrected before acceptable data can be
generated.
9. QUALITY CONTROL
9.1 Each laboratory that uses this method 1s required to operate a
formal quality control program. The minimum requirements of this
program consist of an initial demonstration of laboratory cap-
ability and an ongoing analysis of spiked samples to evaluate and
document data quality. The laboratory must maintain records to
document the quality of data that 1s generated. Ongoing data
quality checks are compared with established performance criteria
to determine 1f the results of analyses meet the performance
characteristics of the method. A quality control check standard
must be analyzed to confirm that the measurements were performed in
an 1rv-control mode of operation.
9.1.1 The analyst must make an Initial, one-time, demonstration of
the ability to generate acceptable accuracy and precision
with this method. This ability 1s established as described
1n Section 9.2.
9.1.2 In recognition of advances that are occurring 1n chromato-
graphy, the analyst 1s permitted certain options (detailed
In Section 10.1.I) to Improve the separations or lower the
cost of measurements. Each time such a modification 1s made
to the method, the analyst is required to repeat the
procedure in Section 9.2.
9.1.3 Each day, the analyst must analyze a reagent water blank to
demonstrate that interferences from the analytical system
are under control.
-------
9.1.4 The laboratory must, on an ongoing basis, demonstrate
through the analyses of quality control check standards that
the operation of the measurement system is in control. Thi-s
procedure is described in Section 9.3. The frequency of the
check standard analyses is equivalent to 10S of all samples
analyzed, but at least two samples per month.
9.1.5 On a weekly basis, the laboratory must demonstrate the
ability to analyze low level samples. A procedure for low
level check samples is described in Section 9.4.
9.1.6 The laboratory must maintain performance records to document
the quality of data that is generated.
To establish the ability to generate acceptable accuracy and
precision, the analyst must perform the following operations.
9.2.1 A quality control (QC) check sample concentrate 1s required
containing each regulated analyte, and any additional
analyte which 1s to be reported, at a concentration of 100
times the MCL or 1 yg/mL, whichever 1s smaller, 1n
methanol. The QC check sample must be prepared by the
laboratory using stock standards prepared Independently from
those used for calibration.
9.2.2 Analyze seven S-mL QC check samples at 1/5 MCL or 2 ug/L
accordlng to the method beginning in Sect. 10. Each sample
1s produced by Injecting 10 uL of QC check sample
concentrate Into 5 mL of reagent water 1n a glass syringe
through the syringe valve.
9.2.3 Calculate the average recovery (T) 1n ug/L, and the standard
deviation of the recovery (s) in ug/L for each analyte using
the seven results. Calculate the MDL for each analyte as
specified 1n Ref. 2. The calculated MDL must be less than
the spike level.
9.2.4 For each analyte, (7) must be between 901 and UOS of the
true value. Additionally, s must be <_ 35X of X. If s and T
for all analytes meet the "criteria, the system performance
1s acceptable and analysis of actual samples can begin. If
any s exceeds the precision limit or any "X falls outside the
range for accuracy, the system performance 1s unacceptable
for that analyte.
NOTE: The large number of analytes present a substantial
probability that one or more will fail at least one of the
acceptance criteria when all analytes are analyzed.
-------
9.2.5 When one or more of the analytes tested fall at least one of
the acceptance criteria, the analyst must proceed according
to Section 9.2.2 only for the analytes which failed the test.
9.3 The laboratory must demonstrate on a regular basis (See Section
9.1.4) that the measurement system is in control by analyzing a
quality control sample for all analytes of interest at the MCL or
10 ug/L, whichever 1s smaller.
9.3.1 Prepare a QC check standard by adding SO uL of QC check
sample concentrate (Section 9.2.1) to 5 mL of regent water
in a glass syringe.
9.3.2 Analyze the QC check according to Section 10, and calculate
the recovery for each analyte. The recovery must be between
60S and 1402 of the expected value.
9.3.3 If the recovery for any analyte falls outside the designated
range, the analyte has failed the acceptance criteria. A
check standard containing each analyte that failed must be
re-analyzed.
9.4 On a weekly basis, the laboratory must demonstrate the ability to
analyze low level samples.
9.4.1 Prepare a low level check sample by spiking 10 «L of QC
cneck sample concentrate to 5 mL of reagent water and
analyze according to the method 1n Sect. 10.
9.4.2 For each analyte, the recovery must be between SOS and 140S
of the expected value.
9.4.3 When one or more analytes fall the test, the analyst must
repeat the test only for those analytes which failed to meet
the criteria. Repeated failure, however, will confirm a
general problem with the measurement system. If this
occurs, locate and correct the source of the problem and
repeat the test for all compounds of interest beginning with
9.4.1.
9.5 It Is recomnended that the laboratory adopt additional quality
assurance practices for use with this method. The specific
practices that are most productive depend upon the needs of the
laboratory and the nature of the samples. Field duplicates may be
analyzed to assess the precision of the environmental measurements.
Whenever possible, the laboratory should analyze standard reference
materials and participate in relevant performance evaluation
studles.
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10. PROCEDURE
10.1 INITIAL CONDITIONS
10.1.1 Reconmended chromatographic conditions are summarized in
Section 5.3.2. Estimated retention times and MOL that can
be achieved under these conditions are given in Table 1.
Other packed coluireis may be used if the requirements of
Section 9.2 are met.
10.1.2 Calibrate the system dally as described in Section 8.1.4.
10.1.3 Adjust the purge gas (nitrogen or helium) flow rate to 40
mL/min. Attach the trap inlet to the purging device and
open the syringe valve on the purging device.
10.2 SAMPLE INTRODUCTION AND PURGING
10.2.1 Remove the plungers from two 5-mL syringes and attach a
closed syringe valve to each. Warm the sample to room
temperature, open the sample (or standard) bottle, and
carefully pour the san^jle Into one of the syringe barrels to
just short of overflowing. Replace the syringe plunger,
invert the syringe, and compress the sample. Open the
syringe valve and vent any residual air while adjusting the
sample volume to 5.0 mL. If applicable, add the internal
calibration standard to the sample through the syringe
valve. Close the valve. Fill the second syringe 1n an
Identical manner from the same sample bottle. Reserve this
second syringe for a reanalysls 1f necessary.
10.2.2 Attach the sample syringe valve to the syringe valve on the
purging device. Be sure that the trap 1s cooler than 25*C,
then open the sample syringe valve and Inject the sample
Into the purging chamber. Close both valves and Initiate
purging. Purge the sample for 11.0 * 0.1 min at ambient
temperature (Figure 3).
10.3 SAMPLE DESORPTION - After the 11-flrin purge, attach the trap to the
chromatograph, adjust the purge and trap system to the desorb mode
(Figure 4) and Initiate the temperature program sequence of the gas
chromatograph. Introduce the trapped materials to the GC column by
rapidly heating the trap to 180*C while bacJcflushing the trap with
an inert gas between 20 and 60 mL/min for 4.0 * 0.1 min.
If rapid heating cannot be achieved,^the GC column must be used as
a secondary trap by cooling 1t to 30"C (subambient temperature if
poor peak geometry and random retention problems persist) Instead
of the initial operating temperature for analysis. While the
extracted sample is being Introduced into the gas chromatograph,
empty the purging device using the sample syringe and wash the
chamber with two 5-fflL flushes of reagent water. After the purging
device has been emptied, leave the syringe valve open to allow the
purge gas to vent through the sample Introduction needle.
-------
10.4 TRAP RECONDITIONING - After desorbing the sample for four rain,
recondition the trap by returning the purge and trap system to the
purge mode. Wait 15 s, then close the syringe valve on the purging
device to begin gas flow through the trap. Maintain the trap
temperature at 180*C. After approximately seven m1n, turn off the
trap heater and open the syringe valve to stop the gas flow through
the trap. When the trap 1s cool, the next sample can be analyzed.
11. CALCULATIONS
11.1 Identify each organohallde in the sample chromatogram by comparing
the retention time of the suspect peak to retention times generated
by the calibration standards and the laboratory control standard
(Sect. 8.2.2).
11.2 Determine the concentration of the unknowns by using the
calibration curve or by comparing the peak height or area of the
unknowns to the peak height or area of the standards as follows.
Concentration of Peak height sample Concentration of
unknown (ug/L) ¦ Peak height standard * standard (ug/L)
11.3 Report the results for the unknown samples 1n ug/L. Round off the
results to the nearest 0.1 »g/L or two significant figures.
12. ACCURACY ANO PRECISION
12.1 Single laboratory (EMSL-Cincfnnatl) accuracy and precision for the
organohaHdes spiked 1n Ohio River water and carton-filtered tap
water are presented 1n Table 2.(1)
12.2 This method was tested by 20 laboratories using drinking water
spiked with various organohalides at six concentrations between 8
and 505 ug/L. Single operator precision, overall precision, and
method accuracy were found to be directly related to the
concentration of the analyte. Linear equations to describe these
relationships are presented 1n Table 3.(8)
13. REFERENCES
1. "The Oetermlnation of Halogenated Chemicals in Water by the Purge
and Trap Method, Method 502.1,* U.S. Environmental Protection
Agency, Environmental Monitoring and Support Laboratory,
Cincinnati, Ohio 45268, April, 1981.
2. Slaser, J.A., O.L. Foerst, G.D. McXee, S.A. Quave, and W.L. Budde,
¦Trace Analyses for Wastewaters," Environ. Sci. Techno!., 15, 1426,
1981.
3. 'Carcinogens-Working with Carcinogens," Department of Health,
Education, and Welfare, Public Health Service, Center for Oisease
Control, National Institute for Occupational Safety and Health,
Publication No. 77-206, August, 1977.
-------
4. "QSHA Safety and Health Standards, General Industry," (29CFR1910),
Occupational Safety and Health Administration, OSHA 2206, (Revised,
January 1976).
5. "Safety in Academic Chemistry Laboratories," American Chemical
Society Publication, Conmittee on Chemical Safety, 3rd Edition,
1979.
6. "Gas Chromatographic Analysis of Purgeable Halocarbon and Aromatic
Compounds in Drinking Water Using Two Oetectors in Series,"
Klngsley, B.A., G1n, C., Coulson, D.M., and Thomas, R.F., Water
Chiorination. Environmental Impact and Health Effects, Volume 4,
Ann Arbor Science.
7. Bellar, T.A. and J.J. Lichtenberg, "The Determination of Synthetic
Organic Compounds 1n Water by Purge and Sequential Trapping
Capillary Column Gas Chromatography," U.S. Environmental Protection
Agency, Environmental Monitoring and Support Laboratory,
Cincinnati, Ohio 45268.
8. "EPA Method Validation Study 23, Method 601 (Purgeable
Halocarbons)," U.S. Environmental Protection Agency, Environmental
Monitoring and Support Laboratory, Cincinnati, Ohio 45268.
-------
Table 1. RETENTION TIMES AND METHOO {DETECTION LIMITS
(MOL) FOR ORGANOHALIDES
Retention
Time (sec)
MOL
Analyte
Column 1
Column 2
(ua/L)
Chloromethane
90
317
0.01
Bromcmethane
130
423
0.03
01ch1orodi f1uoromethane
157
(a)
(a)
Vinyl chloride
160
317
0.006
Chloroethane
200
521
0.008
Methylene chloride
315
607
(a)
Trich1orof1uoromethane
431
(a)
(a)
1,1—01ch1oroethene
476
463
0.003
8romoch1oromethane
509
760
(a)
1,1-01ch1oroe th ane
558
754
0.002
trans-1,2-01ch1oroethene
605
563
0.002
ci s—1,2-01ch1oroethene
605
726
0.002
Chloroform
641
725
0.002
1,2-01ch1oroethane
684
921
0.002
01broraomethane
698
895
(a)
1,1,1-Tri ch1oroethane
756
786
0.003
Carton tetrachloride
781
664
0.003
8romod1chloromethane
819
877
0.002
01chloroacetonitr1le(b)
884
(a)
0.04
l,2-01chloropropane
895
997
(a)
1,1-01ch1oropropene
904
(a)
(a)
Trichloroethene
948
787
0.001
1,3-01ch1oropropane
973
(a)
(a)
01bromoch1oromethane
989
997
(a)
1,1,2-Tri ch1oroethane
991
1084
0.007
1,2-01bromoethane
1046
1131
0.03
2-Chloroethylethyl ether(b)
1056
(a)
0.02
2-Chloroethylvinyl ether(b)
1080
(a)
0.02
Bromoform
1154
1150
0.02
1,1,1,2-Tetrach1oroethane
1163
1302
(a)
1,2,3-Trlchloropropane
1279
(a)
(a)
Ch1orocyc1ohexane(b)
1283
(a)
(a)
1,1,2,2-Tetrach1oroethane
1297
(a)
0.01
T etrach1oroethene
1300
898
0.001
Pentach1oroethane(6)
1300
(a)
(a)
1-Ch1orocyc1ohexene(b)
1345
1186
(a)
Chlorobenzene
1451
1130
0.001
1,2-01bromo-3-ch1oropropane
1560
(a)
0.03
Bromobenzene
1626
(a)
(a)
2-Chlorotoluene
1927
1320
(a)
bis-2-Chloroisopropyl ether
1931
(a)
(a)
1,3-01ch1orobenzene
2042
1346
(a)
1,2-01ch1orobenzene
2094
1411
(a)
1,4-01ch1orobenzene
2127
1340
(a)
(a) « Not determined.
(b) - Compound not a method analyte.
(c) ¦ Pentachloroethane apparently decomposes to tetrachloroethene in the
analytical system.
-------
Table 1. (CONTINUED)
Column 1 Conditions: Carbopack 8(60/80 mesh) coated with IS SP-1000 packed
in an 8 ft x 0.1 1n ID stainless steel or glass column with helium carrier
gas at 40 mL/min flow rate. #Column temperature held at 40*C for 3 min then
programmed at 8*C/min to 220*C and held for 15 min.
Column 2 conditions: Porisil-C (100/120 mesh) coated with chemically bonded
n-octane packed in a 6 ft x 0.1 in ID stainless steel or glass column with
helium carrier gas at 40 rrt./min flow rate. Column temperature held at 50*C
for 3 min then programmed at 6*C/min to 170*C and held for 4 min.
-------
Table 2. SINGLE LA80RAT0RY ACCURACY ANO PRECISION FOR ORGANCHALIDES
IN OHIO RIVER WATER ANO ORINKING WATER
Arralyte
8romobenzene
Bronoch 1 orcmethane
3rcmodi ch1o romethane
Srcmofarm
Carton tetrachloride
Chlorobenzene
Ch1orocyc1ohexane(a)
1-Otlorocycl ohexene( a)
Chloroethane
2-Chloroethylethyl ether(a)
Chlorcmethane
2-Qilorotoluene
01bromoch1oromethane
l,2-01bromoethane
01bromomethane
1.2-01chlorobenzene
1.3-01ch1orobenzene
1.4-01chlorobenzene
01chlorod1fluoromethane
1.1-01ch1oroethane
1.2-0i ch1oroethane
1.1-01 chloroethene
1.2-0ichloroethene(b)
1.2-01chloropropane
1.3-01ch1oropropane
1,1-Oichloropropene
Methylene chloride
1,1,1,2-Tetrachloroethane
1,1,2,2-Tetrach1oroethane
Tetr ach1oroethene
1.1.1-Trlchloroethane
1.1.2-Trich1oroethane
Trichloroethene
T rf chlorof1uoromethane
1.2.3-Tri ch1oropropane
Vinyl Chloride
Relative
Spike
Average
Number
Standard
Standard
Level
Recovery
or
Deviation
Oevlatio
(i»q/L)
%
Samoles
(ua/l)
(?)
0.40
93
20
0.047
12
0.40
90
19
0.038
9.5
0.20
100
17
0.013
6.5
0.20
95
17
0.030
15.0
0.20
90
17
0.014
7.0
0.40
88
18
0.037
9.3
0.40
93
21
0.033
8.3
0.40
93
21
0.051
12.8
0.40
93
20
0.071
18
0.40
95
18
0.030
7.5
0.40
93
16
0.034
8.5
0.40
85
20
0.037
9.3
0.20
95
17
0.014
7.0
0.40
93
18
0.050
12.5
0.40
100
5
0.032
8.0
0.40
95
21
0.053
13
0.40
95
21
0.033
8.3
0.40
90
20
0.051
13
0.40
103
12
0.081
20
0.20
95
17
0.012
6.0
0.20
110
17
0.014
7.0
0.40
88
18
0.027
9.3
0.40
88
20
0.028
7.0
0.40
95
20
0.014
3.5
0.40
98
21
0.026
6.5
0.40
88
18
0.037
9.3
0.20
85
17
0.024
12.0
0.40
93
20
0.032
8.0
0.40
95
18
0.036
9.0
0.20
90
17
0.019
9.5
0.40
93
20
0.032
8.0
0.40
95
15
0.024
5.0
0.20
94
17
0.012
6.0
0.40
90
21
0.037
9.3
0.40
100
20
0.038
9.5
0.20
110
12
0.029
15
(a) » Compound not included in proposed monitoring requirement.
Ch) » Includes cis- and trans- Isomers.
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Table 3. SINGLE ANALYST PRECISION, OVERALL PRECISION
ANO ACCURACY FOR ORGANOHALIOES IN DRINKING WATER *
Anal yte
Bromodich1oromethane
Broraofonn
Carton Tetrachloride
Chiorobenzene
Chloroethane
Chloroform
Chloromethane
01bromoch1oromethane
1.2-01ch1orobenzene
1.3-01ch1orobenzene
1.4-01ch1orobenzene
1,1-01chloroethane
1~2-01ch1oroethane
1.1-01ch1oroethene
trans-1,2-01ch1oroethene
1.2-01chloropropane
Methylene Chloride
1,1,2,2-Tetrach1oroethane
Tetrachloroethene
1.1.1-Tr1chloroethane
1.1.2-Tr1chloroethane
Trichl oroethene
Tr1ch1orof1uoromethane
Vinyl Chloride
Single Analyst
Overal1
Accuracy
as Mean
Preci s i on
Precision
SecovervfTl
0.137 +
1.41
0.187
3.06
l.QGC + 0.96
0.107 *
0.20
0.247
1.25
1.02C - 1.31
0.107 ~
1.57
0.207
1.09
1.00C - 2.20
0.077 ~
1.71
0.167
1.43
1.00C - 1.39
0.07T «•
0.65
0.197
0.39
1.08C - 1.97
0.057 ~
5.58
0.097
6.21
0.90C +3.44
0.287 *
0.27
0.497
1.51
0.91C - 0.99
0.107 ~
1.55
0.237
0.91
0.98C * 2.89
0.127 +
2.02
0.177
2.26
0.91C + 1.12
0.157 ~
0.64
0.247
1.48
0.91C - 0.13
0.097 +
0.39
0.157
0.39
0.91C ~ 0.26
0.097 *
0.47
0.187
1.13
0.93C - 2.04
0.067 ~
1.69
0.187
1.21
1.03C - 0.41
0.127 ~
0.13
0.317
0.71
1.03C - 1.16
0.167 ~
0.29
0.247
0.95
0.98C - 1.02
0.197 -
0.61
0.277
0.10
0.98C * 1.19
0.087 *
1.04
0.177
2.43
0.97C - 1.50
0.097-
1.42
0.207
1.65
0.92C - 0.82
0.177 ~
0.96
0.257
0.58
0.96C * 0.35
0.147 -
0.33
0.277
0.76
0.92C ~ 0.02
0.067 ~
0.99
0.197
0.69
0.34C ~ 0.83
0.137 *
0.23
0.327
0.57
0.92C - 0.10
0.227 «¦
0.03
0.307
0.64
0.92C ~ 1.21
0.147 -
0.17
0.327
0.07
1.06C - 1.86
T - Mean recovery, 1n 119/I
C - True value for the concentration, 1n ug/L
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:«THOO 503.1. VOLATILE AROMATIC ANO UNSATURATED ORGANIC
COMPOUNOS IN WATER 3Y P'jRGc ANO TRAP GAS CHROMATOGRAPHY
(1981, Ed. Rev. 1986)
1. SCOPE AND APPLICATION
1.1 This method is applicable for the determination of various volatile
aromatic and unsaturated compounds 1n finished drinking water, raw
source water, or drinking water 1n any treatment stage.(1) The
following compounds can be determined by this owthod:
Analyte
CAS Mo.
Benzene
71-43-2
Bromobenzene
108-86-1
n-8utylbenzene
104-51-8
sec-8utylbenzene
135-98-8
tert-8uty1benzene
98-06-6
Chlorobenzene
108-90-7
2-Chlorotoluene
95-49-8
4-Chlorotoluene
106-43-4
l,2-01chlorobenzene
95-50-1
1,3-01chlorobenzene
541-73-1
1,4-01chlorobenzene
106-46-7
Ethylbenzene
100-41-4
Hexach1orobutadlene
87-68-3
Isopropylbenzene
98-82-8
4-1sopropy1to 1uene
99-87-6
Naphthalene
91-20-3
n-Propylbenzene
103-65-1
Styrene
100-42-5
Tetrach1oroethene
127-18-4
Toluene
108-88-3
1,2,3-Tr1chlorobenzene
87-61-6
1,2,4-Tr 1ch1orobenzene
120-82-1
Trichloroethene
79-01-6
1,2,4-Trlmethylbenzene
95-63-6
1,3,5-Tr! methylbenzene
108-67-8
o-Xylene
95-47-6
m-Xylene
108-38-3
p-Xylene
106-42-3
1.2 This method 1s not applicable to the determination of styrene in
chlorinated drinking water?. The rapid oxidation rate of this
compound prevents the effective use of a dechlorinating agent as a
preservation technique for 1t.
-------
1.3 Single laboratory accuracy and precision data show that this
procedure is useful for the detection and measurement of
multi-component mixtures spiked into finished water and raw source"
water at concentrations between 0.05 and 0.5 ug/L. The method
detection limit (MOL) (2) for each analyte is presented in Table 1
(1). Some laboratories may not be able to achieve these- detection
limits since results are dependent upon instrument sensitivity and
matrix effects. Individual aromatic compounds can be measured at
concentrations up to 1500 ug/L. Determination of complex mixtures
containing partially resolved compounds may be hampered by
concentration differences larger than a factor of 10.
1.4 This method 1s recommended for use only by analysts experienced in
the measurement of purgeable organics at the low ug/L level or by
experienced technicians under the close supervision of a qualified
analyst.
SUMMARY OF METHOD
2.1 Highly volatile organic compounds with low water solubility are
extracted (purged) from a 5-mL sample by bubbling an inert gas
through the aqueous sample. Purged sample components are trapped
in a tube containing a suitable sorbent material. When purging 1s
complete, the sorbent tube 1s heated and backflushed with an Inert
as to desorb trapped sample components onto a gas chromatography
GC) column. The gas chromatograph 1s temperature progranmed to
separate the method analytes which are then detected with a
photoIonization detector.
2.2 A second chromatographic column 1s described that can be used to
confirm GC Identifications and measurenents. Alternatively,
corrflraatory analyses may be performed by gas chromatography/mass
spectrometry (GC/MS) according to Method 524.1 or Method 524.2 1f
sufficient material 1s present.
INTERFERENCES
3.1 Ourlng analysis, major contaminant sources are volatile materials
1n the laboratory and Impurities 1n the Inert purging gas and 1n
the sorbent trap. The use of non-polytetrafluoroethylene (PTFE)
plastic tubing, non-PTFE.thread sealants, or flow cbntrollers with
rubber cooponents 1n the purging device should be avoided since
such materials out-gas organic compounds which will be concentrated
in the trap during the purge operation. Analyses of laboratory
reagent blanks (Sect. 9.1.3) provide Information about the presence
of contaminants. When potential Interfering peaks are noted 1n
laboratory reagent blanks, the analyst should change the purge gas
source and regenerate the molecular sieve purge gas filter (Figure
1). Subtracting blank values from sample results 1s not permitted.
-------
OPTIONAL
FOAM ft—- EXIT \i IN.
TRAP S~ ^\
0. 0.
—14MM o. 0.
INLET '4 IN.
Tf—
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11
i *
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3B—2-1AT STRINGS VALVE
~-nca. 20 GAUGE SYHINGE NSDLfi
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~10MM. 0. 0.
iH^-hnlsi
14 IN. 0. 0.
1001 GLASS FRIT
MHJIUM POROSITY
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y STAINLESS STSL
pfe|l3X MOLECULAR
SIEVE PURGE
yy GAS RLTB
PURGE GAS
FLOW
CONTROL
Rgur* 1. Purging dtviai
-------
3.2 Interfering contamination may occur when a sample containing To*
concentrations of volatile organic compounds 1s analyzed
Immediately after a sample containing relatively high
concentrations of volatile organic compounds. A preventive
technique is between-sample rinsing of the purging apparatus and
sample syringes with ttno portions of reagent water. After analysis
of a sample containing hign concentrations of volatile organic
compounds, one or more laboratory reagent blanks should be analyzed
to check for cross contamination. For samples containing large
amounts of water soluble materials, suspended solids, high boiling
compounds or high levels of compounds being determined, it may be
necessary to wash out the purging device with a soap solution,
rinse it with distilled water, and then dry 1t in an oven at 105"C
between analyses.
3.3 Excess water will cause a negative baseline deflection in the.
chromatogram. The method provides for a dry purge period to
prevent this problem.
4. SAfETY
4.1 The toxicity or carcinogenicity of i*1cals used 1n this method
has not been precisely defined; each cnesrfcal should be treated as
a potential health hazard, and exposure to these chemicals should
be minimized. Each laboratory Is responsible for maintaining
awareness of OSHA regulations regarding safe handling of chemicals
used 1n this method. Additional references to laboratory safety
are available (3-5) for the Information of the analyst.
4.2 The following method analytes have been tentatively classified as
known or suspected human or manna11 an carcinogens: benzene,
l,4-d1chlorobenzene, hexachlorobutadlene, tetrachloroethene, and
trlchloroethene. Pure standard materials and stock standard
solutions of these compounds should be handled in a hood. A
NIOSH/MESA approved toxic gas respirator should be worn when the
analyst handles high concentrations of these toxic compounds.
5. APPARATUS ANO EQUIPMENT
5.1 SAMPLE CONTAINERS - 40-fflL to 120-fflL screw cap vials (Pierce #13075
or equivalent) each equipped with a PTFE-faced silicone septum
(Pierce #12722 or equivalent). Prior to use, wash vials and septa
with detergent and rinse with tap and distilled water. Allow the
vials and septa to air dry at room temperature, place 1n a 105"C
oven for one hour, then remove and allow to cool 1n an area known
to be free of organics.
5.2 PURGE ANO TRAP SYSTEM - The purge and trap system consists of three
separate pieces of equipment: purging device, trap, and desorber.
Systems are conrnercially available from several sources that meet
all of the following specifications.
-------
5.2.1 The all glass purging device (Figure 1} must be designed to
accept 5-
-------
PACKING PROCEDURE
CONSTRUCTION
WOOL
ACTIVATED
CHARCOAL .7.7C3I
GRADE 15
7.1 OR
SUGA GEL
TBIAI 7.7 OS
3XOV-1
GLASS WOOL1
1C*
7 a/FOOT
RESISTANCE
VISE WRAPPED
SOLID
(DOUBLE LAYER)
15CB^
7^/FOOT —
RESISTANCE
WIRE WRAPPED
SOUO
(SINGLE LAYS)
seaH
TRAP INLET
COMPRESSION
RTTING NUT
AND F3RULES
THSMOCOUPLE/
CONTROLLER
S3ISQR
ELECTRONIC
TSflPSATURE
CONTROL
AND
PYROMETER
TUBING 2SCSA
0.1 OS IN. 1.0.
0.12S IN. O.D.
STAINLESS STEH.
Rgura 2. Trap packings and construction to inciuda
daaorto capability
-------
CMUm OAS CSWTWCU
MtSSSUM RSSULATO*
uouto iNjicnON hjitts
column ova
ftJHGI OAS
Pun CONTKQL N—II
13XMCUCULA*
UfVf RWTTOI
.— COM^fWATOKT COLUMN
TO OCTSCTOA
- AMM>mCAL COUUMN
amoNM. 4—9orr column
. SflLSCTION VALVV
*7f?£I , ™a# inlzt
VA*>v*a/ xnstsrAMcsmm
CONTROL
THAyQ—— TjW (o**)
njIKSINQ
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TWANO «
94CUL0 a HCATVS
TO
Ftguro 3. Purga and trap systtm - purge modil
CAMBER GAS
ROW CCNTHOL
LI QUID INJECTION PORTS
PURGE GAS
FU3* CONTROL'
13X aOLfCULMga
scve RLia—^
jS^^JLTU U^T "^ANALTTICAl. COLUMN
^COLUMN OVSI
CONPWATORT COLUMN
OPTIONAL 4^0RT COLUMN
Sa£CT10N VALVE
S-PORT TRAP INLCT
VALVE ; fCSSTMCE WIRE
HEATS!
CONTROL
PURGING
OEVTCS
(tote
ALL UNES 8ETWBI
TRAP AND GC
SHOULD S HEATED
TO OT°C.
Figurw 4. Schematic of purge and trap d«vica - desorb mode
-------
COLUMN: IX SP-1000 ON CAItBOTACKB
PROGRAM: 4BTC-3 MINUIE* iVMINUIE 10 1»#C
DEIECIOR: IIALi 700 A &ECVROLI IIC CONDUCIIVIVI
8
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8
£ 8
8
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8
8
S
8
8
8
RETENIION TIME - MINUIES
Flgur* 6. Oat chromatogram of purgaabla halocarbona
-------
5.3.2.1 Column 1 — 1.5 to 2.5 flt x 0.085 in ID #304 stainless
steel or glass, packed with Si SP-1200 and 1.755
Bentone 34 on Suoelcoport (30/100 mesh) op
equivalent. The flow rate of the helium carrier gas
must be established at 30#mL/min. The column
temperature is held at 50*C for 2 min, then
progranmed at 3*C/m1n to 110*C and held at 110*C
until all compounds have eluted. When not in use,
maintain the column at 110'C. Condition new
SP-1200/9entone columns with carrier gas flow at
120"C for several days before connecting to the
detector. A sample chromatogram obtained with
Column 1 is presented in Figure 6.
5.3.2.2 Column 2 - 1.5 to 2.5 m long x 0.085 1n 10 # 304
stainless steel or glass, packed with 55
l,2,3-trts(2-cyanoethoxy) propane on Chromcsorb W
(60/60 mesh) or equivalent. The flow rate of the
helium carrier gas must be established at 30
nl/m1n. The column temperature must be programmed
to hold at 40*C for 2 m1n, increase to 100* C at
2"C/m1n, and hold at 100*C until all expected
compounds have eluted. A sample chromatogram
obtained with Column 2 1s presented 1n Figure 7.
5.3.3 A high temperature photoIonization detector equipped with
a 10.2 eV lamp Is required (HNU Systems, Inc., Model
PI-51-02 or equivalent).
5.4 SYRINGE AND SYRINGE VALVES
5.4.1 Two 5-mL glass hypodermic syringes with Luer-Lok tip.
5.4.2 Three 2-way syringe valves with Luer ends.
5.4.3 One 25-uL micro syringe with a 2 1n x 0.006 in ID, 22" bevel
needle (Hamilton #702N or equivalent).
5.4.4 Micro syringes - 10, 100 uL.
5.5 MISCELLANEOUS
5.5.1 Standard solution storage containers - 15-mL bottles with
PTFE-Hned screw caps.
6. REAGENT ANO CONSUMABLE MATERIALS
6.1 TRAP PACKING MATERIALS
6.1.1 2,6-01 phenylene oxide polymer, 60/80 mesh, chromatographic
grade (Tenax GC or equivalent).
-------
6.1.2 Methyl silicone packing - OV-1 (3S) on Chromosorb-W, 60/80
mesh or equivalent.
6.2 COLUMN PACKING MATERIALS
6.2.1 52 SP-1200/1.755 3entone 34 on 100/120 mesh Supelcoport or
equivalent.
6.2.2 Si l,2,3-tris(2-cyanoethoxy) propane on 60/80 mesh
Chromosorb W or equivalent.
6.3 REAGENTS
6.3.1 Methanol - demonstrated to be free of analytes.
6.3.2 Reagent water - Prepare reagent water by passing tap water
through a filter bed containing about 0.5 leg of activated
carbon, by using a water purification system, or by boiling
distilled water for 15 mln followed by a 1-h purge with
Inert gas while the water temperature is held at 90"C.
Store in clean, narrow-mouth bottles with PTFE-lined septa
and screw caps.
6.3.3 Hydrochloric acid (1*1) - Carefully add measured volume of
conc. HC1 to equal volume of reagent water.
6.4 STANDARD STOCK SOLUTIONS - These solutions may be purchased as
certified solutions or prepared from pure standard materials using
the following procedures:
6.4.1 Place about 9.8 mL of methanol into a 10-mL ground-glass
stoppered volumetric flask. Allow the flask to stand,
unstoppered, for about 10 m1n or until all alcohol-wetted
surfaces have dried and weigh to the nearest 0.1 mg.
6.4.2 Using a 100-uL syringe, 1rmted1ately add two or more drops of
reference standard to the flask. Be sure that the reference
standard falls directly Into the alcohol without contacting
the neck of the flask.
6.4.3 Rewelgh, dilute to volume, stopper, then mix by inverting
the flask several times. Calculate the concentration 1n
micrograms per microliter from the net gain in weight. When
compound purity is certified at 96S or greater, the weight
can be used without correction to calculate the
concentration of the stock standard.
6.4.4 Store stock standard solutions at 4*C in 15-mL bottles
equipped with PTFE-Hned screw caps. Methanol solutions are
stable for at least four weeks when stored at 4*C.
-------
S.5 SECONDARY DILLTTICN STANOARQS - Use standard stock solutions to
prepare secondary dilution standard solutions that contain the
analytas in methanol. The secondary dilution standards should be
prepared at concentrations that can be easily diluted to prepare
aqueous calibration solutions (Sect. 3.1) that will bracket the
working concentration range. Store the secondary dilution standard
solutions with minimal headsoace and check frequently for signs of
deterioration or evaporation, especially just before preparing
calibration solutions from them. Secondary dilution standard
solutions must be replaced after one month.
7. SAMPLE COLLECTION, PRESERVATION. ANO STORAGE
7.1 SAMPLE COLLECTION
7.1.1 Collect all sanples 1n duplicate. Fill sample bottles to
overflowing. No air bubbles should pass through the sample
as the bottle 1s filled, or be trapped in the sample when
the bottle Is sealed.
7.1.2 When sampling from a water tap, open the tap and allow the
system to flush until the v«ater temperature has stabilized
(usually about 10 m1n). Adjust the flow to about 500 mL/mln
and collect duplicate samples from the flowing stream.
7.1.3 When sampling from an open body of water, fill a 1-quart
wide-mouth bottle or 1-1 Iter beaker with sample from a
representative area, and carefully fill duplicate sample
bottles from the 1-quart container.
7.2 SAMPLE PRESERVATION
7.2.1 Adjust the pH of the duplicate samples <2 by carefully
adding one drop of 1:1 HC1 for each 20 mL of sample volume.
Seal the sanple bottles, PFTE-face down, and shake
vigorously for one minute.
7.2.2 The samples must be chilled to 4*C on the day of collection
and maintained at that temperature until analysis. Field
saiqiles that will not be received at the laboratory on the
day of collection must be packaged for shipment with
sufficient 1ce to ensure that they will be ^ 4 C on arrival
at the laboratory. "
-------
7.3 SAMPLE STORAGE
7.3.1 Stars samoles at 4*C until analysis. The sample storage
area must be free of organic solvent vapors.
7.3.2 Analyze all samples *ithin 14 days of collection. Samples
not analyzed within this period must be discarded and
replaced.
-a. cali3Rat:qn *no standardization
8.1 calibration
3.1.1 A set of at least five calibration standards containing the
method analytes is needed. More than one set of calibration
standards may be required. One calibration standard should
contain each analyte at a concentration aoproaching but
greater than the method detection limit (Table 1) for that
compound; the other standards should contain analytes at
concentrations that define the range of the method.
8.1.2 To prepare a calibration standard, add an appropriate volume
of a secondary dilution standard solution to an aliquot of
reagent water In a volumetric container. Use a microsyrlnge
and rapidly inject the alcoholic standard Into the water.
Remove the needle as quickly as possible after injection.
Aqueous standards are not stable and should be discarded
after one hour unless preserved, sealed and stored as
described in Sect. 7.2.2.
8.1.3 Starting with the standard of lowest concentration, analyze
each calibration standard according to Sect. 10 and tabulate
peak height or area response versus the concentration in the
standard. The results can be used to prepare a calibration
curve for each compound. Alternatively, 1f the ratio of
response to concentration (calibration factor) is a constant
over the working range (<10% relative standard deviation),
linearity through the origin can be assumed and the average
ratio or calibration factor can be used 1n place of a
calibration curve.
8.1.4 The working calibration curve or calibration factor .mist ie
verified on each working day by the measurement of one or
more calibration standards. If the response for any analyte
varies from the predicted response by more than *20S, the
test must be repeated using a fresh calibration standard.
If the results still do not agree, generate a new
calibration curve or use a single point calibration standard
as described in Sect. 8.1.5.
-------
8.1.5 Single point calibration 1s a viable alternative to a
calibration curve. Prepare single point standards frcm the
secondary dilution standards in methanol. The single ooi'nt
standards should be prepared at a concentration that
produces a rssoonse close (*2W) to that of the unknowns.
Qo not use less than 20 uL of the secondary dilution
standard to produce a single point calibration standard in
reagent *atar.
8.1.S As a second alternative to a calibration curve, Internal
standard calibration techniques may be used. a,a,a-Tri-
fluorotoluene is recommended as an internal stanaard for
this method. The Internal standard 1s added to the sample
just before purging. Check the validity of the internal
standard calibration factors dally by analyzing a
calibration standard.
8.2 INSTRUMENT PERFORMANCE - Check the performance of the entire
analytical system dally using data gathered frcm analyses of
reagent blanks, standards, duplicate samples, and the quality
control check standard (Sect. 9.3).
8.2.1 All of the peaks contained In the standard chromatograms
must be sharp and symmetrical. Peak tailing slgnifIcantly
in excess of that shown 1n the method chromatograms (Figures
6 and 7) must be corrected. If only the compounds eluting
before ethyl benzene give random responses or unusually wide
peak widths, are poorly resolved, or are missing, the
problem Is usually traceable to the trap/desorber. If
negative peaks appear early In the chromatogram, increase
the dry purge time to S m1n.
8.2.2 Check the precision between laboratory replicates. A
properly operating system should perform with an average
relative standard deviation of less than 102. Poor
precision 1s generally traceable to pneumatic leaks,
especially around the sample purger or to an Improperly
adjusted lamp Intensity power. Monitor the retention times
for each method analyte using data generated from
calibration standards and the laboratory control standard.
If individual retention times vary by more than 10S over an
8-h period or do not fall within 101 of an established norm,
the source of retention data variance must be corrected
before acceptable data can be generated.
9. QUALITY CONTROL
9.1 Each laboratory that uses this method is required to operate a
formal quality control program. The minimum requirements of this
program consist of an initial demonstration of laboratory cap-
ability and an ongoing analysis of spiked samples to evaluate and
document data quality. The laboratory must maintain records to
-------
document the quality of data that is generated. Ongoing data
quality checks are compared with established performance criteria
to determine if the results of analyses meet the performance
characteristics of the method. A quality control check standard
must be analyzed to confirm that the measurements were performed in
an in-control mode of operation.
9.1.1 The analyst must make an initial, one-time, demonstration or
the ability to generate acceptable accuracy and precision
with this method. This ability is established as described
in Section 9.2.
9.1.2 In recognition of advances that are occurring in chromato-
grapny, the analyst is permitted certain options (detailed
in Section 10.1.1) to improve the separations or lower tne
cost of measurements. Each time such a modification is made
to the method, the analyst 1s required to repeat the
procedure 1n Section 9.2.
9.1.3 Each day, the analyst must analyze a reagent water blank to
demonstrate that Interferences from the analytical system
are under control.
9.1.4 The laboratory must, on an ongoing basis, demonstrate
through the analyses of quality control check standards that
the operation of the measurement system 1s in control. This
procedure is described 1n Section 9.3. The frequency of the
check standard analyses 1s equivalent to 10% of all samples
analyzed but may be reduced 1f spike recoveries from samples
meet all specified quality control criteria.
9.1.5 On a weekly basis, the laboratory must demonstrate the
ability to analyze low level samples. A procedure for low
level check samples 1s described 1n Section 9.4.
9.1.6 The laboratory must maintain performance records to document
the quality of data that is generated. This procedure is
described in Section 9.5.
To establish the ability to generate acceptable accuracy and
precision, the analyst must perform the following operations.
9.2.1 A quality control (QC) check sample concentrate is required
containing each regulated analyte, and any additional
analyte which 1s to be reported, at a concentration of 100
times the MCI or 1 ug/mi., whichever 1s smaller, in
methanol. The QC check sample must be prepared by the
laboratory using stock standards prepared independently from
those used for calibration.
9.2.2 Analyze seven 5-mt QC check samples at 1/5 MCL or 2 ug/L
according to the method beginning 1n Sect. 10. Each sample
-------
1s produced by Injecting 10 uL af QC check sample
concentrate into 5 mL of reagent water In a glass syringe
through the syringe valve.
9.2.3 Calculate the average recovery (7) 1n ug/L, and the standard
deviation of the recovery (s) 1n ug/L for each analyte using
the seven results. Calculate the MOL for each analyte as
specified in Ref. 2. The calculated MOL must oe less than
the spike level.
9.2.4 For each analyte, (7) must be between 90S and HQS of the
true value. Additionally, s must be < 355 of 7. If s and 7
for all analytes meet the criteria, tFe system performance
1s acceptable and analysis of actual samples can begin. If
any s exceeds the precision limit or any 7 falls outside the
range for accuracy, the system performance is unacceptable
for that analyte.
MOTE: The large number of analytes present a substantial
probability that one or more will fall at least one of the
acceptance criteria when all analytes are analyzed.
9.2.5 When one or more of the analytes tested fall at least one of
the acceptance criteria, the analyst must proceed according
to Section 9.2.2 only for the analytes which failed the test.
9.3 The laboratory must demonstrate on a regular basis that the
measurement system 1s 1n control by analyzing a quality control
sample for all analytes of Interest at the MCL or 10 ug/L,
whichever 1s smaller.
9.3.1 Prepare a QC check standard by adding 50 uL of QC check
sample concentrate to 5 mL of regent water in a glass
syringe.
9.3.2 Analyze the QC check according to Section 10, and calculate
the recovery for each analyte. The recovery must be between
60S and 1401 of the expected value.
9.3.3 If the recovery for any analyte falls outside the designated
range, the analyte has failed the acceptance criteria. A
check standard containing each analyte that failed must be
re-analyzed.
9.4 On a weekly basis, the laboratory must demonstrate the ability to
analyze low level samples.
9.4.1 Prepare a low level check sample by spiking 10 uL of QC
check samole concentrate to 5 mL of reagent water and
analyze according to the method 1n Sect. 10.
-------
9.*.2 Fop each analyte, the recovery .mist be between SOS and L40S
of the expected value.
9.4.3 When one or more analytes fail the test, the analyst mist
repeat the test only for those analytes which failed to meet
the criteria. Raoeated failure, however, will confirm a
general problem with the measurement system. If this
occurs, locate and correct the source of the problem and
repeat the test for all compounds of interest beginning witn
9.4.1.
9.5 It is recomnended that the laboratory adopt additional quality
assurance practices for use with this method. The specific
practices that are most productive denend upon the needs of the
laboratory and the nature of the samples. Field duplicates may be
analyzed to assess the precision of the environmental measurements.
Whenever possible, the laboratory should analyze standard reference
materials and participate in relevant performance evaluation
studies.
. PROCEDURE
10.1 INITIAL CONDITIONS
10.1.1 Recomnended chromatographic conditions are summarized in
Sect. 5.3.2. Estimated retention times and MOl that can be
achieved under these conditions are given 1n Table 1. Other
packed columns may be used 1f the requirements of Sect. 9.2
are met.
10.1.2 Calibrate the system daily as described in Sect. 8.1.4.
10.1.3 Adjust the purge gas (nitrogen or helium) flow rate to 40
iri./m1n. Attach the trap inlet to the purging device and
open the syringe valve on the purging device.
10.2 SAMPLE INTRODUCTION ANO PURSING
10.2.1 Remove the plungers from two 5-fflL syringes and attach a
closed syringe valve to each. Warm the sample to room
tenperature, open the sample (or standard) bottle, and
carefully pour the sample Into one of the syringe barrels to
just short of overflowing. Replace the syringe plunger,
Invert the syringe, and compress the sample. Open the
syringe valve and vent any residual a1r while adjusting the
sample volume to 5.0 mL. If applicable, add the Internal
calibration standard to the sample through the syringe
valve. Close the valve. Fill the second syringe 1n an
identical manner from the same sample bottle. Reserve this
second syringe for a reanalysls if necessary.
-------
10.2.2 Attach We sample syringe valve to the syringe valve on the
purging device. Open the sample syringe valve and inject
the samole into the purging chamber. Close both valves and
Initiate purging. Purge the sample for 12.0 • 0.1 min at
ambient temperature (Figure 3).
10.3 TRAP ORY ANO SAMPLE 0ES0RPTI0N - After the 12-fflin purge, adjust the
purge and trap system to the dry purge position (Figure A) for four
min. Emoty the purging device using the sample syringe and wash
the chamber with two 5-mL flushes of reagent water. After the
4-min dry purge, attach the trap to the chromatograoh, adjust the
purge and trap system to the desorb mode (Figure 5) and initiate
the temperature program sequence of the gas chromatograoh.
Introduce the trapped materials to the GC column by rapidly heating
the trap to LSQ'C while backflushing the trap with an inert gas
between 20 and 60 ni/m1n for 4.0 * 0.1 min. The transfer 1s
complete after approximately four min and the column 1s then
rapidly heated to the initial operating temperature for analysis.
10.4 TRAP RECONDITIONING - After desorblng the sample for four m1n,
recondition the trap by returning the purge and trap system to the
purge mode. Wait IS s, then close the syringe valve on the purging
device to begin gas flow through the trap. Maintain the trap
temperature at 1S0*C. After approximately seven m1n, turn off the
trap heater and open the syringe valve to stop the gas flow through
the trap. When the trap is cool, the next sample can be analyzed.
11. CALCULATIONS
11.1 Identify each analyte in the sample chromatograra by comparing the
retention time of the suspect peak to retention times generated by
the calibration standards and the laboratory quality control check
standard (Sect. 9.3).
11.2 Oetemine the concentration of the unknowns by using the
calibration curve or by comparing the peak height or area of the
unknowns to the peak height or area of the standards as follows.
Concentration of Peak height sample Concentration of
unknown Ug/l) • Peak neignt stanaaro * standard Ug/L}
11.3 Report the results for the unknown samples 1n ug/l. Round off the
results to the nearest 0.1 ug/L or two significant figures.
12. ACCURACY ANO PRECISION
12.1 Sfngle laboratory (EMSL-Clncinnati) accuracy and precision for most
of the analytes spiked in Ohio River water and cnlorinated drinking
water are presented in Table 2.(6)
12.2 This method was tested by 20 laboratories using drinking water
spiked with various method analytes at six concentrations between
-------
2.2 and 600 ug/L. Single operator precision, overall precision,
and method accuracy were found to be directly related to the
concentration of tne analyte. Linear eouations to describe these -
relationships are presented in Table 3 (7).
12.3 Multilaboratory studies have been conducted by the Quality
Assurance Branch of SMSL-Cincinnati to evaluate the performance of
various 1 aboratones. Accuracy and precision data applicable to
this method for several purgeable aromatlcs in reagent water are
presented in Table 4 (3).
REFERENCES
1. "The Analysis of Aromatic Chemicals in Water by the Purge and Trao
Method, Method 503.1," U.S. Environmental Protection Agency,
Environmental Monitoring and Support Laboratory, Cincinnati, Ohio
45268, April, 1981.
2. Glaser, J.A., D.L. Foerst, G.O. McKee, S.A. Quave, and W.l. Budde,
"Trace Analyses for Wastewaters," Environ. Sc1. Technol., 15. 1426
1981.
3. "Carcinogens-Working with Carcinogens," Department of Health,
Education, and Welfare, Public Health Service, Center for Olsease
Control, National Institute for Occupational Safety and Health,
Publication No. 77-206, August, 1977.
4. "OSHA Safety and Health Standards, General Industry," (29CFR1910),
Occupational Safety and Health Administration, OSHA 2206, (Revised
January 1976).
5. "Safety in Acadenic Chemistry Laboratories," American Chemical
Society Publication, Connittee on Chemical Safety, 3rd Edition,
1979.
6. Bellar, T.A., J.J. Llchtenberg, "The Determination of Volatile
Aromatic Compounds 1n Drinking Water and Raw Source Water,"
unpublished report, U.S. Environmental Protection Agency,
Environmental Monitoring and Support Laboratory, Cincinnati, Ohio
1982.
7. "EPA Method Validation Study 24, Method 602 (Purgeable Aromatlcs),
U.S. Environmental Protection Agency, Environmental Monitoring and
Support Laboratory, Cincinnati, Ohio 45268.
8. "Analytical Methods and Monitoring Issues Associated with Volatile
Organics in Orlnking Water," U.S. Environmental Protection Agency,
Office of Drinking Water, Washington, O.C., June 1984.
-------
Table 1. RETENTION TIf-ES ANO MCTHOO OETHCTICN LIMITS (MDL)
FOR iMTT-tOO ANALYTIC
Rentgntion Tfrne (sec)
MOL
Analyte
Column 1
Column 2
¦j
-------
Table 1. (CONTINUED)
Column 1 conditions: Suoelcoport (100/120 mesh) coated with 55
SP-1200/1.75S Sentone 34 packed in a 6 ft x 0.085 in ID stainless steel or
glass column with helium carrier at 30 nt/m1n flowrate. Column temoeraturs
1s held at 50*C for 2 min then programmed at 3"C/min to 110"C for a final
hold.
Column 2 conditions: Chromosorb W(60/80 mesh) coated with SS
1,2,3-tris(2-cyanoethoxy)propane packed in a 6 ft x 0.085 in ID stainless
steel or glass column with helium carrier gas at 30 mL/m1n flow rate.
Column temoerature held at 40"C for 2 m1n then progransned at 2*C/min to
100'C for a final hold.
-------
Table 2. SINGLE LABORATORY ACCURACY AMD PRECISION FOR
AROMATIC ANO UNSATURATED ANALYTES IN CHLORINATED
ORINKING WATER AND RAW SOURCE WATER
Spike
Average
Relative
Matrix
Level
Samoles
Recovery
Standard
AnaTyte
Tvtje (a)
ua/L
Analyzed
(S)
Deviation (X)
Benzene
A,3
0.40
13
100
2.3
Srofflobenzene
A,3
0.50
19
93
6.2
n-3utylbenzene
A
0.40
7
78
is.:
sec-3uty1benzene
A
0.40
7
80
11. C
tert-8utylbenzene
A
0.4O
7
88
8.7
Chlorobenzene
A,B
O.SO
19
96
5.8
1-Chlorocyclohexene (b)
A,3
0.50
19
89
7.1
4-Chlorotoluene
A,B
0.50
17
91
5.0
1,2-01chlorobenzene
A, 3
0.50
18
92
7.1
1,3-01chlorobenzene
A,3
0.50
19
91
8.5
1,4-01chlorobenzene
A,3
O.SO
19
95
6.4
Ethylbenzene
A
0.40
7
93
8.5
Hexach1orobutadlene
A
0.50
10
74
16.3
IsopropyIbenzene
A
0.40
7
88
8.7
Naphthalene
A,B
0.50
16
92
14.8
n-Propy1benzene
A
0.40
7
83
9.3
Tetrach1oroethene
A,B
0.50
19
97
7.8
Toluene
A,3
0.40
13
94
6.6
1,2,3-Trlchlorobenzene
A, 3
0.50
IS
85
10.4
1,2,4-Tr1chlorobenzene
A,B
0.50
13
86
10.1
Tr1chloroethene
A,3
0.50
19
97
6.3
a,a,a-Tr1f1uorotoluene(c)
A,8
O.SO
18
88
9.7
1,2,4-Tr1methylbenzene
A
0.40
7
75
8.7
1,3, S-T r1methy1benzene
A
0.50
10
92
8.7
m-Xylene
A
0.40
7
90
7.7
o-Xylene
A
0.40
7
90
7.2
p-Xylene
A
0.40
7
85
8.7
(a) • Matrix A 1s drinking water. Matrix 3 1s raw source water.
(b) - Not a method analyte.
(c) • Recomnended Internal standard (Sect. 3.1.6).
-------
Table 3. SINGLE ANALYST PRECISION, OVERALL PRECISION,
AND ACCURACY FOR PURGEA8LE AR0MA7ICS IN ORI.NKINS WATER
Single Analyst Overall Accuracy as
Precision Precision Mean Recoverv(7)
Aoalyte (uo/L) f uc/L) (-jg/i.)
Benzene
0.117
-
0.06
0.227
1.11
0.97C
~
0.35
Chiorobenzene
0.107
0.12
0.167
0.36
0.94C
0.12
1,2-01ch1orobenzene
0.107
0.42
0.187
~
0.23
0.91C
*
0.44
1,3-01ch1orobenzene
0.087
0.33
0.157
~
0.33
0.93C
*
0.21
1,4-01ch1orobenzene
0.097
~
0.39
0.157
0.39
0.91C
~
0.26
Ethylbenzene
0.107
•¥
0.18
0.207
~
0.68
0.97C
~
0.41
Toluene
0.107
~
0.18
0.217
*
0.16
0.94C
~
0.17
7 ¦ mean recovery Ug/L)
C ¦ true value for the concentration (ug/L)
-------
Table 4. ACCURACY ANO PRECISION DATA FCR P'JRGH3L£ ARCMATICS
FROM MULTIUeGRATGRY PSSFCR.MANC2 iVAL'JATIQN STUOI-S
Average
Measured Relative
Solfce Concen- Standard Averica
Level Number of tractions Deviation Recovery
Analyte (uo/L) Laboratories (uq/L) (?) (si
Benzene
94.1
9
91.9
13.5
98
47.0
10
47.0
11.3
100
IS.8
8
18.7
16.4
ICO
8.10
11
6.22
40.8
38
Chlorobenzene
41.4
5
39.8
6.20
96
27.5
7
27.1
12.1
98
13.8
6
14.3
6.73
104
5.52
8
5.65
25.3
102
1,2-Oichlorobenzene
96.9
5
72.9
31.6
75
19.4
4
16.5
18.8
85
1,4-01chlorobenzene
68.6
5
62.5
22.8
91
13.7
5
14.6
29.1
107
1,2,4-TrlcMorobenzene
80.8
6
77.6
14.3
96
6.7
6
8.46
30.7
126
-------
OPTIONAL
FOAM
ft-—EXIT * IN.
TRAP /
J S o. o.
J—14MM o. 0.
\
INLET % IN.
y-— 0. 0.
% IN.
0. 0. EOT
«•
• i
11
i'
i'
• t
a
»
o
SAMPLE INLET
I—2-WAT SYRINGE VALVE
17CU. 20 GAUGE STRINGS NEEDLE
CNsMM. 0. 0. RU88EH SEPTUM
10MM. 0. D.
10MM GLASS FWT
USI14M POROSITT
LET
% IN. 0. 0.
1/18 IN. O.D.
y STAINLESS
pfe)l3J MOLECULAR
SIEVE PURGE
^ GAS RLTE3
f
PURGE GAS
FLO*
CONTROL
Figure 1. Purging devica
-------
PACKING PROCEDURE
GLASS mm
WOOL
THVAX 23 CJ
K0V.t1ca
GLASS WOOL bum
CONSTRUCTION
COMPRESSION FITTING
"NUT AND F3RULE5
14FT.7A/FOOT RESISTANCE
'anRE WRAPPED SOLID
THERMOCOUPLE/
CONTROLLER
SH4SOR
B-ECTHONIC
TBdPSHATURE
CONTROL
AND
PYROMETEl
TUBING 25 CM.
0.105 IN. t.O.
0.125 IN. O.O.
STAINLESS STES.
TRAP INLET
figure 2. Trap packings and construction to inciude
dasorb capability
-------
CAWlGt GAS PLOW CONTROL
PKOSUJtE REGULATOR ^^4
UOUtO INJECTION 0CHT3
PURGE GAS
B»QW CONTROL
13S MOLECULAJt
SIEVE /1LTB»
/rrr
COLUMN OVEN
dsm,pii^0egSE^c8u""
'J U Li U I ' ¦ ANALYTICAL COLUMN
OmONAl 4-PCKT COLUMN
. !W,-_ SBJCTCN VALVE
^ffve /TRA"NL£T
/ / WSJSTANCE wtni
X—v^MEAT® CONTROL
10
~ 5 TRAP /op*)
Not«:ALL UNES BCTWE2N
THA^ ANO SC
SHOULD U MEAT®
dkvics to tare
Figure 3T Purge and trap system - purge mode.
CARRIER GAS
FLOW CONTROL
PRESSURE
REGULATOR v
UOUtO INJECTION PORTS
.COLUMN OVEfl
PURGE SAS
FLOW CONTROL
132 MOLECULAR
SIEVE FILTER
irkfuinMWSKSJ0" C0LUMN
L. B2L§r.anAiXT ^-ANALYTICAL COLUMN
\OPTIONAL 4-PORT COLUMN
SaECTION VALVE
•-PORT TRAP INLET
VALVE j ffiSISTANCE WIRE
ZZCON)
180 °C
HEATER
r CONTROL
WRONG
DEVICE
Now.
ALL UNES BETYVE9I
TRAP ANO SC
SHOULD BE HEATS!
TO SO*C
Figure 4. Schematic of purge and trap device - desorb mode
-------
Garner Gas Row Control
Regulator
\
Liquid Injection Pcra
A
Column Qvan
"fTl n fl r n Confirmatory Column
:| n n n r__L> To Detacter
| "^^--AnaiyticaJ Column
Pur^a Gas
Row Control
Vaiva-3
Optional 4-Port Coiumn
SeJacdon Valve .
Trap Inlet (T«nax End)
Rasstanca WIra
Valve-1
Vant
Haatar Control
13X Molecular
Steve Fhar
All Unas Between
Trap and GC
Should be Heated
to 80°C
Figur# 8. Pur^e and trap system-dry moda.
-------
COIUMNi IP-1109/ !.»« •INIOH* 99
moon AM: IO'C-1 ndwlll rC/nk to 110*0
Of trefoil! PIIOIOIONUAIION
f AMPtCt 0 I Or# /I aiANOAKD MMIUIII
nCNVENIIOM lIMB.mtntitM
riQUnE 0. ClinOMATOOnAM OF test mixture
-------
CCLUMN: S* 1-2.3-7*13 (S-CYANCJTHCXT]
PHGPAMS ON C*flCMC3Cfl3—W
?WQG3 A.V<: *C"C-2-~invftM 2*C/ifcn. ta ICC'C
orracroa: PHOTciONiXATiaN
&I& 2.3-*/1 STANDAPO MIXT-RS
t 13 It
HfiNTSNTICN TTME.minutw
AQUAE 7. CHHCMATOGHAAI OP TEST M13CTURS
-------
METHGO 504. 1.2-0I3R0M0ETHANE (EDB) ANO
1.2-OI3ROMO-3-CHLOROPROPANE {DSCP) IN WATER
8Y MICROEXTRACTION ANO GAS CHROMATOGRAPHY
(1985, Ed. Rev. 1986)
SCOPS AND APPLICATION
1.1 This method (1,2,3) is applicable to the determination of the
following compounds in finished drinking water and unfinished
groundwater:
1.2 For compounds other than the above mentioned analytes, or for other
sample sources, the analyst must demonstrate the usefulness of the
method by collecting precision and accuracy data on actual samples
(4) and provide qualitative confirmation of results by Gas
Chromatography/Mass Spectrometry (GC/MS) (5).
1.3 The experimentally determined method detection limits (MOL) (6) for
EDB and D8CP were calculated to be 0.01 ug/L. The method has been
shown to be useful for these analytes over a concentration range
from approximately 0.03 to 200 ug/L. Actual detection limits are
highly dependent upon the characteristics of the gas chromato-
graphic system used.
SUMMARY OF METHOO
2.1 Thirty-five mL of sample are extracted with 2 mL of hexane. Two uL
of the extract are then Injected into a gas chromatograph equipped
with a linearized electron capture detector for separation and
analysis. Aqueous calibration standards are extracted and analyzed
1n an Identical manner as the samples 1n order to compensate for
possible extraction lasses.
2.2 The extraction and analysis time is 30 to 50 minutes per sample
depending upon the analytical conditions chosen. (See Table 1 and
Figure 1.)
2.3 Confirmatory evidence can be obtained using a dissimilar column
(see Table 1). When component concentrations are sufficiently high
(> 50 ug/L), Method 524.1 (7) may be employed for improved speci-
ficity.
INTERFERENCES
3.1 Impurities contained in the extracting solvent usually account for
the majority of the analytical problems. Solvent blanks should be
Analyte
1,2-01bromoethane
1,2-01bromo-3-Ch1oropropane
106-93-4
96-12-8
CAS No.
-------
analyzed on each new bottle of solvent before use. Indirect daily
cnecks on the extracting solvent are obtained by monitoring the
sample blanks (7.1.1). Whenever an interference is noted in the "
sample blank, the analyst should reanalyze the extracting solvent.
Low level irrterferences generally can be removed by distillation or
column cnromatograohy (3); however, it is generally more economical
to obtain a new source solvent. Interference-free solvent is
defined as a solvent containing less than 0.1 ug/l individual
analyte interference. Protect interference-free solvents by
storing in an area known to be free of organochlorlne solvents.
3.2 Several Instances of accidental sample contamination have been
attributed to diffusion of volatile organics through the septum
seal Into the sample bottle during shipment and storage. The
sample blank (7.1.1) is used to monitor for this problem.
3.3 This 11qu1d/11qu1d extraction technique efficiently extracts a wide
boiling range of non-polar organic compounds and, 1n addition,
extracts polar organic components of the sample with varying
efficiencies.
3.4 ED8 at low concentrations may be masked by very high levels of
dlbromochloromethane (DBCM), a comnon chlorinated drinking water
contaminant, when using the confirmation column (Sect. 5.8.2.2).
4. SAFETY
4.1 The toxicity and carcinogenicity of chemicals used 1n this method
has not been precisely defined; each chemical should be treated as
a potential health hazard, and exposure to these chemicals should
be minimized. Each laboratory is responsible for maintaining
awareness of OSHA regulations regarding safe handling of chemicals
used 1n this method. Additional references to laboratory safety
are available (8-10) for the information of the analyst.
4.2 EDB and 08CP have been tentatively classified as known or suspected
human or manna! 1 an carcinogens. Pure standard materials and stock
standard solutions of these compounds should be handled 1n a hood
or glovebox. A NIOSH/MESA approved toxic gas respirator should be
worn when the analyst handles high concentrations of these toxic
compounds.
5. APPARATUS ANO EQUIPMENT
5.1 SAMPLE CONTAINERS - 40-mL screw cap vials (Pierce #13075 or
equivalent) each equipped with a PTFE-faced silicone septum (Pierce
#12722 or equivalent). Prior to use, wash vials and septa with
detergent and rinse with tao and distilled water. Allow^the vials
and septa to air dry at room temperature, place in a 105*C oven for
one hour, then remove and allow to cool in an area known to be free
of organics.
-------
5.2 VIALS, auto sampler, screw cap with PTFE-faced septa, 1.8 mL,
Varian #96-000099-00 or equivalent.
5.3 MICRO SYRINGES - 10 and 100 uL.
5.4 MICRO SYRINGE - 25 uL with a 2-inch by 0.006-inch needle - Hamilton
702N or equivalent.
5.5 PIPETTES - 2.0 and 5.0 mL transfer.
5.6 VOLUMETRIC FLASKS - 10 and 100 mL, glass stoppered
5.7 STANDARO SOLUTION STORAGE CONTAINERS - 15-mL bottles with
PTFE-lined screw caps.
5.8 GAS CHROMATOGRAPHY SYSTEM
5.8.1 The GC must be capable of temperature programing and should
be equipped with a linearized electron capture detector and a
capillary column splitless Injector.
5.8.2 Two gas chromatography columns are recommended. Column A is
a highly efficient column that provides separations for ED8
and OBCP without interferences from trlhalomethanes (Sect.
3.4). Column A should be used as the primary analytical
column unless routinely occurring analytes are not adequately
resolved. Column 8 1s recorunended for use as a confirmatory
column when GC/MS confirmation is not available. Retention
times for EDB and DBC? on these columns are presented in
Table 1.
5.8.2.1 Column A - 0.32 mm ID x 30M long fused silica
capillary with dimethyl silicone mixed phase
(Durawax-0X3, 0.25 um film, or equivalent). The
linear velocity of the helium carrier gas 1s
established at 25 cm/sec. The column temperature is
programmed to hold at 40#C for 4 min, to increase to
190 C at 8#C/m1n, and hold at 190*C for 25 m1n or
until all expected compounds have eluted. Injector
temperature: 200*C. Detector temperature: 290*C.
(See Figure 1 for a sample chromatogram and Table 1
for retention data).
5.8.2.2 Column 8 (confirmation column) - 0.32mm ID x 30M
long fused silica capillary with methyl polysiloxane
phase (DB-1, 0.25 um film, or equivalent). The
linear velocity of the helium carrier gas is
established at 25 an/sec. The column temperature is
programmed to hold at 40*C for 4 min, to increase to
270 C at 10'C/minute, and hold at 270*C for 10 min
or until all expected compounds have eluted.
Injector temperature: 200*C. Detector temoera-
ture: 290*C. (See Table 1 for retention data).
-------
6. REAGcMTS ANO CONSUMABLE MATE3IALS
6.1 REAGENTS
6.1.1 Hexane extraction solvent - UV Grade, 3urdick and Jackson
#216 or equivalent.
6.1.2 Methyl alcohol - ACS Reagent Grade, demonstratad to be free
of analytes.
6.1.3 Sodium chloride, NaCl - ACS Reagent Grade - For pretreatment
before use, pulverize a batch of NaCl and place in a muffle
furnace at room temperature. Increase the temoerature to
400*C for 30 minutes. Place in a bottle and cap.
6.2 STANDARO MATERIALS
6.2.1 1,2-Oibromoethane - 99t, available from Aldrich Chemical
Conpany.
6.2.2 l,2-01bromo-3-chlonjpropane - 99.4%, available from AMVAC
Chemical Corporation, Los Angeles, California.
6.3 REAGENT WATER - Reagent water is defined as water free of inter-
ference when employed in the procedure described herein.
6.:.1 Reagent water can be generated by passing tap water through
a filter bed containing activated carbon. Change the
activated carbon whenever the criteria in Sect. 9.1.2 cannot
be met.
6.3.2 A Mlllipore Super-Q Water System or its equivalent may be
used to generate delonized reagent water.
6.3.3 Reagent water may also be prepared by boiling water for 15
min. Subsequently, while maintaining the temperature at
90*C, bubble a contaminant-free inert gas through the water
at 100 (rt-/ra1nute for 1 hour. While still hot, transfer the
water to a narrow mouth screw cap bottle with a Teflon seal.
6.3.4 Test reagent water each day it 1s used by analyzing it
according to Sect. 10.
6.4 STANDARO STOCX SOLUTIONS - These s.: 'utions may be purchased as
certified solutions or prepared from pure standard materials using
the following procedures:
6.4.1 Place about 9.8 mL of methanol into a 10-mL ground-glass
stoppered volumetric flask. Allow the flask to stand,
unstoppered, for about 10 min and weigh to the nearest
0.1 mg.
-------
6.4.2 Use a 100—jL syringe and immediately add two or more drops
of standard material to the flask. Se sure that the
standard material falls directly into the alcohol without
contacting the neck of the flask.
5.4.3 Reweich, dilute to volume, stooper, then mix by inverting
the flask several times. Calculate the concentration in
micrograms per microliter from the net gain in weight.
6.4.4 Store stock standard solutions in 15-mL bottles equipped
with PTFE-lined screw caps. Methanol solutions prepared
from liquid anafytes are stable for at least four weeks when
stored at 4*C.
6.5 SECONDARY DILUTION STANDARDS — Use standard stock solutions to
prepare secondary dilution standard solutions that contain both
analytes 1n methanol. The secondary dilution standards should be
prepared at concentrations that can be easily diluted to prepare
aqueous calibration standards (Sect. 8.1.1) that will bracket the
working concentration range. Store the secondary dilution standard
solutions with minimal headspace and check frequently for signs of
deterioration or evaporation, especially just before preparing
calibration standards. The storage time described for stock
standard solutions 1n Sect. 6.4.4 also applies to secondary
dilution standard solutions.
6.5 QUALITY CONTROL (QC) CHECK SAMPLE CONCENTRATE (0.25 ug/mL) —
Prepare a QC check sample concentrate of 0.25 ug/mL of each analyte
from the standard stock solutions prepared in Sect. 6.4.
6.7 MOL CHECK SAMPLE CONCENTRATE (0.05 ug/mL) — Dilute 2 mL QC check
sample concentrate (Sect. 6.6) to 10 mL with methanol.
7. SAMPLE COLLECTION, PRESERVATION, ANO STORAGE
7.1 SAMPLE COLLECTION
7.1.1 Replicate field blanks must be handled along with each
sample set, which 1s composed of the samples collected from
the same general sampling site at approximately the same
time. At the laboratory, fill a minimum of two sample
bottles with reagent water, seal, and ship to the sampling
site along with sample bottles. Wherever a set of samples
1s shipped and stored, it must be accompanied by the field
blanks.
7.1.2 Collect all samples In duplicate. Fill sample bottles to
overflowing. No a1r bubbles should pass through the sample
as the bottle is filled, or be trapped in tne sample when
the bottle is sealed.
7.1.3 When sampling from a water tap, open the tap and allow the
system to flush until the water temperature has stabilized
-------
(usually about 10 min). Adjust the flow to aoout 500 .it/mm
and collect duolicate samples from the flowing stream.
7.1.4 When samoling from a well, fill a wide-^outh bottle or
beaker with samole, and carefully fill duplicate <10—tiL
sample bottles.
7.2 SAMPLE PRESERVATION
7.2.1 The samples must be chilled to 4*C on the day of collection
and maintained at that temperature until analysis. Field
samples that will not be received at the laboratory on the
day of collection must be packaged for shipment with suffi-
cient 1ce to Insure that they will be below 4*C on arrival
at the laboratory.
7.2.2 The addition of sodium thiosulfate as a dechlorlnatlng agent
and/or acidification to pH 2 with 1:1 HC1, comnon preserva-
tion procedures for purgeable compounds, have been shown to
have no effect on EDB and DBCP and, therefore, their use is
not recommended for samples to be analyzed for these
analytes.
7.3 SAMPLE STORAGE
7.3.1 Store samples and field blanks together at 4*C until
analysis. The sample storage area must be free of organic
solvent vapors.
7.3.2 Analyze all samples within 28 days of collection. Samples
not analyzed within this period must be discarded and
replaced.
8. CALIBRATION ANO STANDARDIZATION
8.1 CALIBRATION
8.1.1 At least three calibration standards are needed. One should
contain ED8 and 08CP at a concentration near to but greater
than the method detection limit (Table 1) for each compound;
the other two should be at concentrations that bracket the
range expected in samples. For example, if the MOL is
0.01 wg/L, and a sample expected to contain approximately
0.10 ug/L 1s to be analyzed, aqueous standards should be
prepared at concentrations of 0.02 ug/L, 0.10 ug/L, and
0.20 ug/L.
8.1.2 To prepare a calibration standard, add an approoriate volume
of a secondary dilution standard solution to an aliquot of
reagent water in a volumetric flask. Oo not add less than
20 uL of an alcoholic standard to the reagent water or Door
precision will result. Use a 25-uL micro syringe and
-------
rapidly inject the alcoholic standard into the exoanded area
of the filled volumetric flask. Renove the needle as
quickly as possible after injection. Mix by inverting the
flask several times. Discard the contents contained in the
neck of the flask. Aqueous standards should be prepared
fresh daily unless sealed and stored without headspace as
described in Sect. 7.
3.1.3 Analyze each calibration standard according to Sect. 10 and
tabulate peak height or area response versus the
concentration in the standard. The results can be used to
prepare a calibration curve for each compound.
Alternatively, if the ratio of response to concentration
(calibration factor) 1s a constant over the working range
(<102 relative standard deviation), linearity through the
origin can be assumed and the average ratio or calibration
factor can be used in place of a calibration curve.
8.1.4 Single point calibration 1s a viable alternative to a
calibration curve. Prepare single point standards from the
secondary dilution standard solutions. The single point
calibration standard should be prepared at a concentration
that produces a response close (*202) to that of the
unknovms.
8.2 INSTRUMENT PERFORMANCE - Check the performance of the entire
analytical system daily using data gathered from analyses of reagent
blanks, standards, duplicate samples, and the laboratory control
standard (Sect. 9.2.2).
8.2.1 Peak tailing significantly in excess of that shown in the
method chromatogram must be corrected. Tailing problems are
generally traceable to active sites on the SC column or the
detector operation.
8.2.2 Check the precision between replicate analyses. A properly
operating system should perform with an average relative
standard deviation of less than 102. Poor precision 1s
generally traceable to pneumatic leaks, especially at the
injection port.
9. QUALITY CONTROL
9.1 Each laboratory that uses this method is required to operate a
formal quality control program. The minimum requirements of this
program consist of an initial demonstration of laboratory detection
limits capability and an ongoing analysis of spiked samoles to
evaluate and document data quality. Ongoing data quality checks
are compared with established performance criteria to determine if
the results of analyses meet the performance characteristics of the
method. When results of sample spikes indicate atypical method
-------
performance, a quality control check standard .mist be analyzed to
confirm that the measurements were performed in an in-control mcae
of operation.
9.1.1. The analyst .mist make an initial determination of the method
detection limits and demonstrate the ability to generate
acceptable accuracy and precision with this method. This is
established as described in Section 9.2.
9.1.2 In recognition of advances that are occurring in
chromatography, the analyst is permitted certain options to
Improve the separations or lower the cost of measurements.
Each time such a modification is made to the method, the
analyst is required to repeat the procedure in Section 9.2.
9.1.3 Each day, the analyst must analyze a reagent water blank to
demonstrate that 1nterferences from the analytical system
are under control.
9.1.4. The laboratory must, on an ongoing basis, demonstrate
through the analyses of quality control check standards that
the operation of the measurement system 1s 1n control. This
procedure 1s described In Section 9.3. The frequency of the
check standard analyses is equivalent to 5S of all samples
analyzed.
9.1.5 On a weekly basis, the laboratory must demonstrate the
ability to analyze low level samples. The procedure for low
level check samples 1s described 1n Sect. 9.4.
To establish the ability to achieve low detection limits and
generate acceptable accuracy and precision, the analyst must
perform the following operations:
9.2.1 Prepare seven MOl check samples at 0.05 ug/L by spiking
35 ug/L of the MOL check sample concentrate (Sect. 6.7) into
35-mL allquots of reagent water in 40-mL bottles. Cap and
nrix well.
9.2.2 Analyze the well-mixed MOL check samples according to the
method beginning In Section 10.
9.2.3 Calculate the average concentration found (T) 1n vg/L, and
the standard deviation of the concentrations (s) in ug/L,
for each analyte using the seven results. Then calculate
the MOL at 99X confidence level for seven replicates (6) as
3.143s.
9.2.4 For each analyte, T must be between 80S and 1205 of the true
value. Additionally, the MOL may not exceed the 0.G5 ug/L
spiked concentration. If both analytes meet the acceotanca
criteria, the system performance is acceptable and analysis
of actual samples can begin. If either analyte fails to
-------
meet a crfterian, repeat the test. It Is recoimended that
the laboratory repeat the MDL determination on a regular
basis.
9.3 The laboratory must demonstrate on a frequency equivalent to 10S of
the sample load that the measurement system is in control by
analyzing a QC check sample of both analytes at 0.2S ug/l.
9.3.1 Prepare a QC check sample (0.25 ug/l) by adding 35 ul of QC
check sample concentrate (Sect. 6.6) to 35 mL of reagent
water in a 40-mL bottle.
9.3.2 Analyze the QC check sample according to Sect. 10 and
calculate the recovery for each analyte. The recovery must
be between 60S and 1402 of the expected value.
9.3.3 If the recovery for either analyte falls outside the
designated range, the analyte fails the acceptance
criteria. A second check standard containing each analyte
that failed must be analyzed. Repeated failure, however,
will confirm a general problem with the measurement system.
If this occurs, locate and correct the source of the problem
and repeat the test.
9.4 On a weekly basis, the laboratory must demonstrate the ability to
analyze low level samples.
9.4.1 Prepare an MOL check sample (0.05 ug/l) as outlined in Sect.
9.2.1 and analyze according to the method in Sect. 10.
9.4.2 The instrument response must indicate that the laboratory's
MDL is distinguishable from instrument background signal.
If not, repeat the MDL test in Sect. 9.2.1. For each
analyte, the recovery must be between 602 and 1402 of the
expected value. When either analyte falls the test, the
analyst must repeat the test only for that analyte which
failed to meet the criteria. Repeated failure, however,
will confirm a general problem with the measurement system
or faulty samples and/or standards. If this occurs, locate
and correct the source of the problem and repeat the test.
9.5 It is reconmended that the laboratory adopt additional quality
assurance practices for use with this method. The specific
practices that are most productive depend upon the needs of the
laboratory and the nature of the samples. Field duplicates may be
analyzed to assess the precision of the environmental
measurements. Whenever possible, the laboratory should analyze
standard reference materials and participate in relevant
performance evaluation studies.
10. PROCEDURE
10.1 SAMPLE PREPARATION
-------
10.1.1 Remove samples and standards from storage and allow then ta
reach room temperature.
10.1.2 For samples and field blanks, contained in 40-id. bottles,
renwve the container cap. Discard a 5htiL volume using a
5-mL transfer pipette. Replace the container cap and weigh
the container with contents to the nearest O.lg and record
this weight for subsequent sample volume determination
(Sect. 10.3).
10.1.3 For calibration standards, QC check standards and reagent
blank, measure a 3S-mL volume using a 50-mL graduated
cylinder and transfer it to a 40-mL sample container.
10.2 MICROEXTRACTION ANO ANALYSIS
10.2.1 Renwve the container cap and add 7g NaCl (Sect. 6.1.3) to
the sample.
10.2.2 Recap the sample container and dissolve the NaCl by shaking
by hand for about 20 sec.
10.2.3 Remove the cap and, using a transfer pipette, add 2.0 mL of
hexane. Recap and shake vigorously by hand for 1 min.
Allow the water and hexane phases to separate. (If stored
at this stage, keep the container upside down.)
10.2.4 Remove the cap and carefully transfer 0.5 mL of the hexane
layer into an autosampler using a disposable glass pipette.
10.2.5 Transfer the remaining hexane phase, being careful not to
include any of the water phase, 1nto,a second autosampler
vial. Reserve this second vial at 4*C for a reanalysls if
necessary.
10.2.6 Transfer the first sample vial to an autosampler set up to
inject 2.0 uL portions into the gas chromatograph for
analysis. Alternately, 2 uL portions of samples, blanks and
standards may be manually Injected, although an auto-
sampler 1s strongly recomnended.
10.3 DETERMINATION OF SAMPLE VOLUME
10.3.1 For samples and field blanks, remove the cap from the sample
container.
10.3.2 Olscard the remaining sample/hexane mixture. Shake off the
remaining few drops using short, brisk wrist movements.
10.3.3 Reweigh the empty container with original cap and cai-jlata
the net weight of sample by difference to the nearest
0.1 g. This net weight is equivalent to the volume of water
(in ill.) extracted. (Sect. 11.3)
-------
11. CALCULATIONS
11.1 Identify ED8 and DBCP in the sample chromatogram by comparing the
retention time of the suspect peak to retention times generated by*
the calibration standards and the laboratory control standard.
11.2 Use the calibration curve or calibration factor (Sect. 8.1.3) to
directly calculate the uncorrected concentration (Ci) of each
analyte in the sample (e.g., calibration factor x response).
11.3 Calculate the sample volume (Vs) as equal to the net sample
weight:
Vs a gross weight (Sect. 10.1.2) - bottle tare (Sect. 10.3.3).
11.4 Calculate the corrected sample concentration as:
Concentration, ug/L ¦ C, K
s
11.5 Report the results for the unknown samples in vg/L. Round off the
results to the nearest 0.01 ug/L or two significant figures.
12. ACCURACY ANQ PRECISION
12.1 Single laboratory (EMSL-C1ncinnat1) accuracy and precision at
several concentrations 1n tap water are presented 1n.Table 2 (11).
The method detection limits are presented 1n Table 1.
12.2 In a preservation study extending over a 4-week period, the average
percent recoveries and relative standard deviations presented 1n
Table 3 were observed for reagent water (acidified),, tap water and
groundwater. The results for acidified and non-acidified samples
were not significantly different.
13. REFERENCES
1. Glaze, W.W., Lin, C.C., Optimization of Liquid-Liquid Extraction Methods
for Analysis of Organics in Water, EPA-600/S4-83-052, January 1984.
2. Henderson, J.E., Peyton, G.R. and Glaze, W.H. (1976). In "Identifiction
and Analysis of Organic Pollutants 1n Water" (L.H. Keith ed.),
pp. 105-111. Ann Arbor Sci. Publ., Ann Arbor, Michigan.
3. Richard, J.J., G.A. Junk, "Liquid Extraction for Rapid Determination of
Halomethanes in Water," Journal AWWA, 69, 62, January 1977.
4. "Handbook for Analytical Quality Control in Water and Wastewater
Laboratories^%EPA-600/4-79-019, U. S. Environmental Protection Agency,
Environmental Monitoring and Support Laboratory - Cincinnati, Ohio
45263, March 1979.
-------
5. 8udde, W.L., J.W. Eichelberger, "Organic Analyses Using Gas
Chrofflatograohy-Mass Soectrcmetry," Ann Arbor Science, Ann Arbor,
Michigan 1979.
6. Glaser, J.A. at al., "Trace Analyses for Wastewaters," environmental
Science and Technology, IS, 1426 (1981).
7. "Methods for the Determination of Organic Compounds In Finished Drinking
Water and Raw Source Water,' Environmental Monitoring and Support
Laboratory, Cincinnati, Ohio, Septe.nber I98S.
8. "Carcfnogens-Working with Carcinogens," Department of Health, Education,
and Welfare, Public Health Service, Center for Disease Control, National
Institute of Occupational Safety and Health, Publication No. 77-206,
August, 1977.
9. "OSHA Safety and Health Standards, General Industry," (29CFR1910),
Occupational Safety and Health Adnrf n 1 strati on t OSHA 2206, (Revised,
January 1976).
10. "Safety in Academic Chemistry Laboratories," American Chemical Society
Publication, Comnittee on Chemical Safety, 3rd Edition, 1979.
11. Winfleld, T.U., et al. "Analysis of Organohallde Pesticides in Drinking
Water by Mlcroextraction and Gas Chromatography." In preparation.
-------
Table 1. CHROMATOGRAPHIC CONDITIONS AND METHOD DETECTION
LIMITS FOR 1,2-OIBROMOETHANE (EDB) AND
1.2-0IBR0M0-3-CHL0R0PR0PANE (D8CP)
Analyte Retention Time, Win MQL, uc/l
' Column A Column 8
ED8 9.5 8.9 O.Ol
DBCP 17.3 15.0 0.01
Column A conditions: Durawax-DX 3 (0.25 ym film thickness) in a 30 m long x
0.32 nin ID fused silica capillary column with hel1um#carrier gas at
25 cm/sec. Column temperature held isothermal at 40#C for 4 min, then
programmed at 8*C/min to 180*C for final hold.
Column 8 conditions: D8-1 (0.25 um film thickness) in a 30 m long x 0.32 mm
ID fused silica capillary column with helium carrier gas at 25 cm/sec.
Columi temperature held isothermal at 40*C for 4 min, then programmed at
10*C/min to 270*C for final hold.
Table 2. SINGLE LABORATORY ACCURACY AND PRECISION
FOR EDB AND DBCP IN TAP WATER
Number
of
Analyte Samples
EDB 7
7
7
OBCP 7
7
7
Spike
Level
(uq/L)
Average
Accuracy
<*>
Relative
Standard
Deviation
(*)
0.03
114
9.5
0.24
98
11.8
50.0
95
4.7
0.03
90
11.4
0.24
102
8.3
50.0
94
4.8
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Table 3. ACCURACY A,NO PRECISION AT 2.0 Ug/L
OVER A 4-WEEX STUOY PER 100
Average
Relative
a
Number
Accuracy
Std. Oev.
Analyte
Matrix^
of Samoles
(S Recovery)
(%)
E08
RW—A
15
104
4.7
GW
IS
101
2.5
GW-A
16
96
4.7
tw
16
93
6.3
TW-A
16
93
6.1
D8CP
RW-A
16
105
a.2
GW
16
105
6.2
GW-A
16
101
8.4
TW
16
95
10.1
TW-A
16
94
6.9
^Matrix Identities
RW-A - Reagent water at pH 2
SW > Groundwater, ambient pH
GW-A • Groundwater at pH 2
TW • Tap water, ambient pH
TW-A - Tap water at pH 2.
-------
COLUMN: Fused silica capillary
LIQUID PHASE: Durawax-DX3
FILM THICKNESS: 0.25 urn
COLUMN DIMENSIONS: 30 M x 0.317 no ID
l
X
X
X
x
x
x
_L
X
8
10
20 22 24 28 30
12 14 16 18
TIME (MIN)
figure I. Extract of fleagent Water Spiked at 0.114 ug/L with EDO and DDCP
-------
METHOD 524.1. VOLATILE ORGANIC COMPOUNDS IN WATER 3Y
PURGE ANO TRAP GAS CHROMATOGRAPHY/MASS SPECTROMETRY
(Revised 1985)
1. SCOPE ANO APPLICATION
1.1 This method is applicable for the determination of various volatile
organic compounds in finished drinking water, raw source water, or
drinking water 1n any treatment stage. (1) The following
compounds can be determined by this method:
Analyte
Chemical Abstract Services
Reqistry Number
Benzene
71-43-2
Bromobenzene
108-86-1
Bromochlorcmeth ane
74-97-5
Bromodi ch1orcmethane
75-27-4
8romoform
75-25-2
Bromcmethane
74-83-9
sec-Butylbenzene
135-98-8
tert-8utylbenzene
98-06-6
Carbon tetrachloride
56-23-5
Chlorobenzene
108-90-7
Chloroethane
75-00-3
Chloroform
67-66-3
Chloromethane
74-87-3
2-Chlorotoluene
95-49-8
4-Gilorotoluene
106-43-4
D1bromoch1oromethane
124-48-1
1,2-01bromo-3-chloropropane
96-12-8
1,2-01bromoethane
106-93-4
01bromomethane
74-95-3
1,2-01ch1orobenzene
95-50-1
1,3-01chlorobenzene
541-73-1
1,4-01ch1orobenzene
106-46-7
01ch1orodlf1uoromethane
75-71-8
1,1-01ch1oroethane
75-34-3
1,2-01ch1oroethane
107-06-2
1,1-01ch1oroethene
75-35-4
c1s-1,2-01ch1oroethene
156-59-4"
-------
Analyte
trans-lf2-0ichloroethene
1.2-Cichloropropane
1.3-Oi ch1oropropane
2,2-Oichloropropane
1,1-Oi ch1oropropene
Ethylbenzene
Hexach1orobutadi ene
Isopropylbenzene
Methylene chloride
n-Propylbenzene
Styrene
1,1,1,2-Tetrachloroethane
1,1,2,2-Tetrach1oroeth ane
T etrachloroethene
Toluene
1.1.1-Trich1oroethane
1.1.2-Trichloroethane
THchl oroethene
Tr1ch1orof1uoromethane
1.2.3-Trichloropropane
Vinyl chloride
o-Xylene
m-Xylene
p-Xylene
Chenical Abstract Services
Reolstry Number
156-60-5
78-87-5
142-28-9.
590-20-7
563-58-6
100-41-4
87-68-3
98-82-8
75-09-2
103-65-1
100-42-5
630-20-6
79-34-5
127-18-4
108-88-3
71-55-6
79-00-5
79-01-6
75-69-4
96-18-4
75-01-4
95-47-6
108-38-3
106-42-3
1.2 Method detection limits (MOLs) (2) are compound dependent and vary
with purging efficiency and concentration. The MOLs for selected
analytes are presented 1n Table 1. The applicable concentration
range of this method 1s compound and Instrument dependent but 1s
approximately 0.2 to 200 ug/l. Analytes that are Inefficiently*
purged from water will not be detected when present at low
concentrations, but they can be measured with acceptable accuracy
and precision when present 1n sufficient amounts. Determination of
some geometrical Isomers (I.e., xylenes) may be hampered by
coelution.
1.3 This method 1s recommended for use only by analysts experienced in
the measurement of purgeable organics at the low yg/l level or by
experienced technicians under the close supervision of a qualified
analyst.
2. SUMMARY OF METH00
2.1 Highly volatile organic compounds with low water solubility are
extracted (purged) from the sample matrix by bubbling an inert gas
through the aqueous sample. Purged sample components are trapped
in a tube containing suitable sorbent materials. When purging is
-------
complete, the sortent tube is heated and backflushed with helium to
desorb trapped samole camoonents onto a gas chromatograohy (GCJ
column. The column is temperature programmed to separata the
method analytes which are then detected with a mass spectrometer
(MS) interfaced to the gas chromatograph.
2.2 Tentative identifications are confirmed by analyzing standards
under the same conditions used for samples and comparing resultant
mass spectra and GC retention times. Each identified component is
measured by relating the MS response for an appropriate selected
1on produced by that compound to the MS response for another ion
produced by a compound that is used as an Internal standard.
3. INTERFERENCES
3.1 Ourfng analysis, major contaminant sources are volatile materials
1n the laboratory and impurities in the inert purging gas and in
the sorbent trap. The use of non-polytetrafluoroethylene (PTFE)
plastic tubing, non-PTFE thread sealants, or flow controllers with
rubber components 1n the purging device should be avoided since
such materials out-gas organic compounds which will be concentrated
in the trap during the purge operation. Analyses of laboratory
reagent blanks (Sect. 9.1.3) provide-Information about the presence
of contaminants. When potential Interfering peaks are noted In
laboratory reagent blanks, the analyst should change the purge gas
source and regenerate the molecular sieve purge gas filter (Fig.
1). Subtracting blank values from sample results 1s not permitted.
3.2 Interfering contamination may occur when a sample containing low
concentrations of volatile organic compounds 1s analyzed
1irmed1ately after a sample containing relatively high
concentrations of volatile organic compounds. A preventive
technique Is between-sample rinsing of the purging apparatus and
sample syringes with two portions of reagent water. After analysis
of a sample containing high concentrations of volatile organic
compounds, one or more laboratory reagent blanks should be analyzed
to check for cross contamination. For samples containing large
amounts of water soluble materials, suspended solids, high boiling
compounds or high levels of compounds being determined, it may be
necessary to wash out the purging device with a soap solution^
rinse it with reagent water, and then dry it 1n an oven at 105 C
between analyses.
3.4 Special precautions must be taken to analyze for methylene
chloride. The analytical and sample storage area should be
isolated from all atmospheric sources of methylene chloride,
otherwise random background levels will result. Since methylene
chloride will permeate through PTFE tubing, all gas chromatograohy
carrier gas lines and purge gas plumbing should be constructed from
-------
stainless steel or capper tubing. Laboratory clothing worn by the
analyst should be clean since clothing previously exposed to
methylene chloride fumes during common liquid/liquid extraction
procedures can contribute to sample contamination.
4. SAFETY
4.1 The toxicity or carcinogenicity of chemicals used in this method
has not been precisely defined; each chemical should be treated as
a potential health hazard, and exposure to these chemicals should
be minimized. Each laboratory is responsible for maintaining
awareness of OSHA regulations regarding safe handling of chemicals
used 1n this method. Additional references to laboratory safety
are available (3-5) for the information of the analyst.
4.2 The following method analytes have been tentatively classified as
known or suspected human or mammalian carcinogens: benzene, carbon
tetrachloride, l,4-d1chlorobenzene, l,2-d1chlorethane,
hexach1orobutadiene, 1,1,2,2-tetrach1oroethane,
1,1,2-trlchloroethane, chloroform, l,2-d1bromoethane,
tetrachloroethene, trlchloroethene, and vinyl chloride. Pure
standard materials and stock standard solutions of these compounds
should be handled in a hood. A NIOSH/MESA approved toxic gas
respirator should be worn when the analyst handles high
concentrations of these toxic compounds.
5. APPARATUS AND EQUIPMENT
5.1 SAMPLE CONTAINERS - 60-mL to 120-mL screw cap vials (Pierce #19832
or equivalent) each equipped with a PTFE-faced silicone septum
(Pierce #12718 or equivalent). Prior to use, wash vials and septa
with detergent and rinse with tap and distilled water. Allow the
vials and septa to air dry at room temperature, place in a 105*C
oven for one hour, then remove and allow to cool 1n an area known
to be free of organics.
5.2 PURGE AND TRAP SYSTEM - The purge and trap system consists of three
separate pieces of equipment: purging device, trap, and desorber.
Systems are commercially available from several sources that meet
all of the following specifications.
5.2.1 The all glass purging device (Fig. 1) must be designed to
accept 25-
-------
5.2.2 Tne trap (Fig. 2) must be at least 25 cm long and have an
Inside diameter of at least 0.105 in. Starting from the
inlet, the trao should contain 1.0 cn of methyl silicone
coated packing and the following amounts of adsorbents: 1/3
of 2,6-diphenylene oxide polymer, 1/3 of silica gel, and 1/3
of coconut charcoal. If it is not necessary to analyze for
dichlorodifluoromethane, the charcoal can be eliminated and
the polymer increased to fill 2/3 of the trap. Before
initial use, the trap should be conditioned overnight at
180*C by backflushing with an inert gas flow of at least 20
mL/m1n. Vent the trap effluent to the room, not to the
analytical column. Prior to dalty use, the trap should be
conditioned for 10 minutes at 180 C with backflushing. The
trap may be vented to the analytical column during daily
conditioning; however, the column must be run through the
temperature program prior to analysis of sauries.
5.2.3 The use of the methyl silicone coated packing 1s
recomnended, but not mandatory. The packing serves a dual
purpose of protecting the Tenax adsorbant from aerosols, and
also of insuring that the Tenax 1s fully enclosed within the
heated zone of the trap thus eliminating potential cold
spots. Alternatively, sllanized glass wool may be used as a
spacer at the trap inlet.
5.2.4 The#desorber must be capable of rapidly heating the trap to
180*C. The polymer section of the trap should not be heated
higher than 200 C or the life expectancy of the trap will
decrease. Trap failure 1s characterized by a pressure drop
1n excess of 3 pounds per square Inch across the trap during
purging or by poor bromoform sensitivities. The desorber
design illustrated 1n F1g. 2 meets these criteria.
5.2.5 Figures 3 and 4 show typical flow patterns for the
purge-sorb and desorb mode.
GAS CHROMATOGRAPHY/MASS SPECTROMETER/DATA SYSTEM (GC/MS/OS)
5.3.1 The GC must be capable of temperature programming and should
be equipped with variable-constant differential flow
controllers so that the column flow rate will renaln
constant throughout desorption and temperature program
operation. The column oven may need to be cooled to <30*C
(Sect. 10.3); therefore, a subambient oven controller may be
required. The GC usually is interfaced to the MS with an
all-glass enrichment device and an all-glass transfer line,
but any enrichment device or transfer line can be used 1f
the performance specifications described in Sect. 9.1 can be
achieved.
-------
5.3.2 Gas Chromatographic Column - 1.5 to 2.5 m x 0.1 in ID
stainless steel or glass, packed with IS SP-1000 on
Carbopack-3 (60/80 mesh) or equivalent. The flow rate of
the helium carrier gas is established at 40 fit/mi n. The
column temperature is programed to hold at 45*C for three
m1n, increase to 220*C at 8*C/m1n, and hold at 220*C for 15
min or until all expected compounds have eluted. During
handling, packing, and programming, active sites can be
exposed on the Carbopack-8 packing which can result in
tailing peak geometry and poor resolution of many
constituents. Pneumatic shocks and rough treatment of
packed columns will cause excessive fracturing of the
Carbopack. If pressure in excess of 60 psi is required to
obtain 40 mL/min carrier flow, the column should be
repacked. A sample chromatogram obtained with this column
1s presented in Fig- 5.
5.3.3 Mass spectral data are obtained with electron-Impact
Ionization at a nominal electron energy of 70 eV. The mass
spectrometer must be capable of scanning from 35 to 450 amu
every 7s or less and must produce a mass spectrum that meets
all criteria in Table 2 when 50 ng or less of
4-bromofluorobenzene is Introduced into the SC. To ensure
sufficient precision of mass spectral data, the desirable MS
scan rate allows acquisition of at least five spectra while
a sample component elutes from the GC.
5.3.4 An interfaced data system (OS) 1s required to acquire,
store, reduce and output mass spectral data. The computer
software must allow searching any GC/MS data file for 1ons
of a specific mass and plotting 1on abundances versus time
or scan number. This type of plot 1s defined as an
extracted 1on current profile (EICP). Software must also
allow Integrating the abundance 1n any EICP between
specified time or scan number limits.
SYRINGE AND SYRINGE VALVES
5.4.1 Two 25-mL glass hypodermic syringes with Luer-Lok tip.
5.4.2 Three 2-way syringe valves with Luer ends.
5.4.3 One 25~vL micro syringe with a 2 1n x 0.006 in ID, 22* bevel
needle (Hamilton #702N or equivalent).
5.4.4 Micro syringes - 10, 100 uL.
5.4.5 Syringes - 0.5, 1.0, and 5-*t, gas tight with shut-off valve.
-------
5.5 MISCELLANEOUS
5.5.1 Standard solution storage containers - 15-mL bottles with
PTFE-1 ined screw caps.
6. REAGENTS ANO CONSUMABLE MATERIALS
6.1 TRAP PACKING MATERIALS
6.1.1 2,6-01 phenylene oxide polymer, 60/80 mesh, chromatographic
grade (Tenax GC or equivalent).
6.1.2 Methyl silicone packing (optional) - OV-1 (35) on Chromo-
sorb W, 60/80 mesh, or equivalent.
6.1.3 SIHca gel - 35/60 mesh, Oavlson, grade 15 or equivalent.
6.1.4 Coconut charcoal - Prepare from Barnebey Cheney, CA-580-26
lot #H-2649 by crushing through 26 mesh screen.
6.2 COLUMN PACXING MATERIALS
6.2.1 IS SP-1000 on 60/80 mesh Carbopack-8 or equivalent.
6.3 REAGENTS
6.3.1 Methanol - Demonstrated to be free of analytes.
6.3.2 Reagent water - Prepare reagent water by passing tap water
through a filter bed containing about 0.5 kg of activated
carbon, by using a water purification system, or by boiling
distilled water for 15 rain followed by a 1-h purge with
Inert gas while the water temperature 1s held at 90*C.
Store 1n clean, narrow-mouth bottles with PTFE-1ined septa
and screw caps.
6.3.3 Hydrochloric acid (1*1) - Carefully add measured volume of
conc. HC1 to equal volume of reagent water.
6.3.4 Vinyl chloride - 99.95 pure vinyl chloride is available from
Ideal Gas Products, Inc., Edison, New Jersey and from
Matheson, East Rutherford, New Jersey. Certified mixtures
of vinyl chloride in nitrogen at 1.0 and 10.0 ppm are
available from several sources.
6.4 STANOARO STOCX SOLUTIONS - These solutions may be purchased as
certified solutions or prepared from pure standard materials using
the following procedures:
-------
6.4.1 Place about 9.8 mL of methanol into a 10-mL ground-glass
stoppered volumetric flask. Allow the flask to stand,
unstoppered, for about 10 min or until all alcohol-wetted
surfaces have dried and weigh to the nearest 0.1 mg.
6.4.2 If the analyte is a liquid at room tesroerature, use a 100-uL
syringe and immediately add two or more drops of reference
standard to the flask. Be sure that the reference standard
falls directly into the alcohol without contacting the neck
of the flask. If the analyte is a gas at room temperature,
fill a 5-mL valved gas-tight syringe with the standard to
the 5.0-mL mark, lower the needle to 5 nm above the methanol
meniscus, and slowly inject the standard into the neck area
of the flask. The gas will rapidly dissolve in the methanol.
6.4.3 Reweigh, dilute to volume, stopper, then mix by inverting
the flask several times. Calculate the concentration in
micrograms per microliter from the net gain 1n weight. When
compound purity 1s certified at 96S or greater, the weight
can be used without correction to calculate the
concentration of the stock standard.
6.4.4 Store stock standard solutions 1n 15-mL bottles equipped
with PTFE-lined screw caps. Methanol solutions prepared
from liquid#analytes are stable for at least four weeks when
stored at 4*C. Methanol solutions prepared from gaseous
analytes are not stable for more than one week when stored
at <0*C; at room temperature, they must be discarded after
one day.
6.5 SECONOARY DILUTION STANDAROS - Use standard stock solutions to
prepare secondary dilution standard solutions that contain the
analytes 1n methanol. The secondary dilution standards should be
prepared at concentrations that can be easily diluted to prepare
aqueous calibration solutions (Sect. 8.1) that will bracket the
working concentration range. Store the secondary dilution standard
solutions with minimal headspace and check frequently for signs of
deterioration or evaporation, especially just before preparing
calibration solutions for them. Storage times described for stock
standard solutions 1n Sect. 6.4.4 also apply to secondary dilution
standard solutions.
6.6 INTERNAL STANOARO SPIKING SOLUTION — Prepare a spiking solution
containing fluorobenzene, and l,2-d1chlorobenzene-d4 in methanol
using the procedures described in Sect. 6.4 and 6.5. It is
reconmended that the secondary dilution standard be prepared at a
concentration of 25 ug/iri. of each internal standard comoound. The
addition of 10 vL of such a standard to 25.0 mL of sample or
calibration standard would be equivalent to 10 ug/L.
-------
6.7 8F3 STANOARD — Prepare a 25-ug/mL solution of bromofluorooenzene
1n methanol.
6.8 LA80RAT0RY QUALITY CONTROL STANOARO CONCENTRATE - Using standard
stock solutions, prepare a solution containing each analyta of
interest of a concentration of 500 times the MCL 1n methanol.
7. SAMPLE COLLECTION. PRESERVATION, ANO STORAGE
7.1 SAMPLE COLLECTION
7.1.1 Collect all samples in duplicate. Fill sample bottles to
overflowing. No air bubbles should pass through the sample
as the bottle is filled, or be trapped in the sample when
the bottle 1s sealed.
7.1.2 When sampling from a water tap, open the tap and allow the
system to flush until the water temperature has stabilized
(usually about 10 m1n). Adjust the flow to about 500 mL/min
and collect duplicate samples from the flowing stream.
7.1.3 When sampling from an open body of water, fill a 1-quart
wide-mouth bottle or 1-1 Iter beaJeer with sample from a
representative area, and carefully fill duplicate sample
bottles from the 1-quart container.
7.2 SAMPLE PRESERVATION
7.2.1 Adjust the pH of the duplicate samples to <2 by carefully
adding one drop of 1:1 HC1 for each 20 mL of sample
volume.(6) Seal the sample bottles, PFTE-face down, and
shake vigorously for one minute.
7.2.2 The samples must be chilled to 4*C on the day of collection
and maintained at that temperature until analysis. Field
samples that will not be received at the laboratory on the
day of collection must be packaged for shipment#with
sufficient ice to ensure that they will be at 4*C on arrival
at the laboratory.
7.3 SAMPLE STORAGE
7.3.1 Store samples at 4*C until analysis. The sample storage
area must be free of organic solvent vapors.
7.3.2 Analyze all samples within 14 days of collection. Samples
not analyzed within this period must be discarded and
replaced.
-------
8. CALIBRATION AND STANDARDIZATION
8.1 PREPARATION OF CALIBRATION STANDARDS
8.1.1 A set of at least five calibration standards containing the
method analytes is needed. One calibration standard should
contain each analyte at a concentration approaching but
greater than the method detection limit (Table 1) for that
compound; the other calibration standards should contain
analytes at concentrations that define the range of the
method.
8.1.2 To prepare a calibration standard, add an appropriate volume
of a secondary dilution standard solution to an aliquot of
reagent water in a volumetric flask. Use a microsyrlnge and
rapidly inject the alcoholic standard into the expanded area
of the filled volumetric flask. Remove the needle as
quickly as possible after Injection. Mix by inverting the
flask three times only. Olscard the contents contained in
the neck of the flask. Aqueous standards are not stable and
should be discarded after one hour unless sealed and stored
as described 1n Sect. 7.2.2.
8.2 CALIBRATION
8.2.1 After meeting the BFB criteria 1n Sect. 10.1, analyze each
calibration standard according to Sect. 10, adding 10 uL of
Internal standard spiking solution directly to the syringe.
Tabulate area response of the characteristic m/z versus the
concentration for each analyte and internal standard.
Calculate response factors (RF) for each analyte using
Equation 1:
RF . Equation 1
Area of the characteristic m/z for the
analyte to be measured.
Area of the characteristic m/z for the
Internal standard.
Concentration of the internal standard, 1n
ug/L.
Concentration of the analyte to be
measured, 1n ug/L.
The choice of which Internal standard is used for an analyte
1s left to the analyst. Normally all aromatics are compared
to l,2-d1chlorobenzene-d4 and all other analytes are
where:
Ag -
A1s "
c1s "
Cs a
-------
compared to the internal standard having the closest
relative retention time.
3.2.2 The results are used to prepare a calibration curve for each
analyte. Alternatively, if the RF for an analyta is
constant (less than 102 RSD) over the working range, the
average RF can be used for that analyte.
8.2.3 The working calibration curve or average response factor
must be verified on each working day by the measurement of
one or more calibration standards. If the quantitation 1on
area for any analyta varies from the response determined for
tha£ standard concentration from the calibration curve or
average RF established 1n Sect. 8.2.2 by more than *20%,
repeat steps 3.2.1 and 8.2.2.
8.2.4 Calibration for vinyl chloride using a certify -us
mixture of vinyl chloride in nitrogen can be accomplished by
the following steps.
8.2.4.1 Fill the purging device with 25.0 mL of reagent
water or aqueous calibration standard.
8.2.4.2 Start to purge the aqueous mixture. Inject a known
volume (between 100 and 2000 uL) of the calibration
gas (at room temperature) directly into the purging
device with a gas tight syringe. Slowly Inject the
gaseous sample through a septum seal at the top of
the purging device at 2000 uL/m1n. Oo not Inject
the standard through the aqueous samp!a Inlet
needle. Inject the gaseous standard before five m1n
of the ll-m1n purge time have elapsed.
8.2.4.3 Oetermlne the aqueous equivalent concentration of
vinyl chloride standard, 1n ug/L, Injected with the
equation:
S - 0.102 (C)(V)
where S - Aqueous equivalent concentration
• of vinyl chloride standard in ug/L;
C • Concentration of gaseous standard in ppm
(v/v);
V m Volume of standard Injected in milli-
liters.
9. QUALITY CONTROL
9.1 Each laboratory that uses this method is required to ooerate a
formal quality control program. The minimum requiresnents of this
-------
program consist of an initial demonstration of laboratory cap-
ability and an ongoing analysis of spiked samples to evaluate and
document data quality. The laboratory must maintain records to
document the quality of data that is generated. Ongoing data
auality checks are compared with established performance criteria
to determine if the results of analyses meet the performance
characteristics of the method. A quality control check standard
must be analyzed to confirm that the measurements were performed in
an in-control mode of operation.
9.1.1 The analyst must make an initial, one-time, demonstration of
the ability to generate acceptable accuracy and precision
with this method. This ability is established as described
- in Section 9.2.
9.1.2 In recognition of advances that are occurring 1n chromato-
graphy, the analyst is permitted certain options (detailed
in Section 10.2.2) to Improve the separations or lower the
cost of measurements. Each time such a modification is made
to the method, the analyst 1s required to repeat the
procedure 1n Section 9.2.
9.1.3 Each day, the analyst must analyze a reagent water blank to
demonstrate that Interferences from the analytical system
are under control.
9.1.4 The laboratory must, on an ongoing basis, demonstrate
through the analyses of quality control check standards that
the operation of the measurement system 1s in control. This
procedure 1s described 1n Section 9.3. The frequency of the
check standard analyses is equivalent to 102 of all samples
analyzed but at least two samples per month.
9.1.5 On a weekly basis, the laboratory must demonstrate the
ability to analyze low level samples. A procedure for low
level check samples is described 1n Section 9.4.
9.1.6 The laboratory must maintain performance records to document
the quality of data that 1s generated. This procedure 1s
described 1n Section 9.5.
To establish the ability to generate acceptable accuracy and
precision, the analyst must perform the following operations.
9.2.1 A quality control (QC) check sample concentrate 1s required
containing each regulated analyte, and any additional
analyte which is to be reported, at a concentration of 500
times the MCL op 5 ug/mL, whichever is smaller, in
methanol. The QC check sample must be prepared by the
laboratory using stock standards prepared Independently from
those used for calibration.
-------
9.2.2 Analyze seven 25-fliL QC check sairoles at 1/5 MCI op 2 ug/l
according to the method beginning in Sect. 10. £ach sanrole
1s produced by injecting 10 uL of QC check sanrole
concentrate into 25 mL of reagent water in a glass syringe
througn the syringe valve.
9.2.3 Calculate the average recovery (7) 1n ug/L, and the standard
deviation of the recovery (s) 1n ug/L for each analyta using
the seven results. Calculate the MDL for each analyte as
.specified in Ref. 2. The calculated MDL must be less than
the spike level.
9.2.4 For each analyte, (7) must be between 902 and 1102 of the
true value. Additionally, s must be 352 of 7. If s and 7
for all analytes meet the criteria, tFe system performance
1s acceptable and analysis of actual samples can begin. If
any s exceeds the precision limit or any 7 falls outside the
range for accuracy, the system performance 1s unacceptable
for that analyte.
NOTE: The large number of analytes present a substantial
probability that one or more will fall at least one of the
acceptance criteria when all analytes are analyzed.
9.2.5 When one or more of the analytes tested fail at least one of
the acceptance criteria, the analyst must proceed according
to Section 9.2.2 only for the analytes which failed the test.
9.3 The laboratory must demonstrate on a regular basis as outlined 1n
Sect. 9.1.4 that the measurement system 1s 1n control by analyzing
a quality control check sample for all analytes of Interest at the
MCL or 10 ug/L, whichever 1s smaller.
9.3.1 Prepare a QC check standard by adding 50 uL of QC check
sample concentrate to 25 mL of regent water in a glass
syringe.
9.3.2 Analyze the QC check according to Section 10, and calculate
the recovery for each analyte. The recovery must be between
60S and 1402 of the expected value.
9.3.3 If the recovery for any analyte falls outside the designated
range, the analyte has failed the acceptance criteria. A
check standard containing each analyte that failed must be
re-analyzed.
9.4 On a weekly basis, the laboratory must demonstrate the ability to
analyze low level samples.
-------
Prepare a low level check samole by spiking 10 UL of QC
check sample concentrate to 25 mL of reagent water and
analyze according to the method in Sect. 10.
For each analyte, the recovery must be between 60* and 1*0%
of the expected value.
When one or more analytes fail the test, the analyst must
repeat the test only for those analytes which failed to meet
the criteria. Repeated failure, however, will confirm a
general problem with the measurement system. If this
occurs, locate and correct the source of the problem and
repeat the test for all compounds of interest beginning with
9.4.1.
9.5 It is reconmended that the laboratory adopt additional quality
assurance practices for use with this method. The specific
practices that are most productive depend upon the needs of the
laboratory and the nature of the samples. Field duplicates may be
analyzed to assess the precision of the environmental measurements.
Whenever possible, the laboratory should analyze standard reference
materials and participate 1n relevant performance evaluation
studies.
PROCEDURE
10.1 DAILY GC/MS PERFORMANCE TESTS
10.1.1 At the beginning of each day that analyses are to be
performed, the GC/MS system must be checked to see if
acceptable performance criteria are achieved for BFB (7).
The performance test must be passed before any samples,
blanks, or standards are analyzed.
10.1.2 At the beginning of each day, inject 2 ul (50 ng) of SFB
solution directly on the column. Alternatively, add 2 uL of
BFB solution to 25.0 mL of reagent water or calibration
standard and analyze the solution according to Sect. 10.
Obtain a background-corrected mass spectrum of BFB and
confirm that all the key m/z criteria 1n Table 2 are
achieved. If all the criteria are not achieved, the analyst
must retune the mass spectrometer and repeat the test until
all criteria are achieved.
10.2 INITIAL CONDITIONS
10.2.1 Acquire GC/MS data for performance tests, standards and
samples using the following instrumental analytes:
9.4.1
3.4.2
9.4.3
-------
Electron Energy: 70 V (nominal)
Mass Range: 35 to 300 amu
Scan Time: To give at least 5 scans per peak but
not to exceed 7 s per scan.
10.2.2 The ooerating conditions for the gas chromatograph are
sunmarized under Section 5.3.2. Table 1 lists the retention
times and MOL that can be achieved under these conditions.
Examples of separations achieved with this method are shown
1n Figures 5. Other columns or chromatographic conditions
may be used if the requirements of Section 9 are met.
10.3 SAMPLE INTRODUCTION ANO PURGING
10.3.1 Adjust the purge gas (nitrogen or helium) flow rate to 40
iflL/n>1n. Attach the trap inlet to the purging device and
open the syringe valve on the purging device.
10.3.2 Remove the plungers from two 25-mL syringes and attach a
closed syringe valve to each. Warm the sample to room
temperature* open the sample (or standard) bottle, and
carefully pour the sample into one of the syringe barrels to
just short of overflowing. Replace the syringe plunger,
Invert the syringe, and compress the sample. Open the
syringe valve and vent any residual air while adjusting the
sample volume to 25.0 mL. Add 10 uL of the internal
standard spiking solution (Section 6.5) to the sample
through the syringe valve. Close the valve. Fill the
second syringe 1n an identical manner from the same sample
bottle. Reserve this second syringe for a ^analysis 1f
necessary.
10.3.3 Attach the sample syringe valve to the syringe valve on the
purging device. 8e sure that the trap 1s cooler than 25*C,
then open the sample syringe valve and Inject the sample
Into the purging chamber. Close both valves and Initiate
purging. Purge the sample for 11.0 * 0.1 m1n at ambient
temperature (Fig. 3).
10.4 SAMPLE DESORPTION - After the 11-min purge, attach the trap to the
chromatograph, adjust the purge and trap system to the desorb mode
(F1g. 4) and initiate the temperature program sequence of the gas
chromatograph and start data acquisition. Introduce the trapoed
materials to the GC column by rapidly heating the trap to 180 C
while backflushing the trap with an inert gas at 15 mL/rnin for 4.0
* 0.1 m1n. While the extracted sample is being introduced Into the
gas chromatograph, empty the purging device using the sample
syringe and wash the chamber with two 25-mL flushes of reagent
-------
water. After the purging device has been emptied, leave the
syringe valve open to allow the purge gas to vent through the
sample introduction needle.
10.5 GAS CHROMATOGRAPHY - Hold the column temperature at 45*C for 3 min,
then program at 8*C/min to 220*C and hold until all analytss
el Lite.
10.5 TRAP RECONDITIONING - After desortiing the sample for 4 m1n,
recondition the trap by returning the purge and trap system to the
purge mode. Wait IS s, then close the syringe valve on the purging
device to begin gas flow through the trap. Maintain the trap
temperature at 180*C. After approximately 7 min, turn off the trap
heater and open the syringe valve to stop the gas flow through the
trap. When the trap is cool, the next sample can be analyzed.
10.7 TERMINATION OF DATA ACQUISITION - When sample components have
eluted from the GC, terminate MS data acquisition and store data
files on the data system storage device. Use appropriate data
output software to display full range mass spectra and appropriate
EICPs. If any ion abundance exceeds the system working range,
dilute the sample aliquot in the second syringe with reagent water
and analyze the diluted aliquot.
QUALITATIVE IDENTIFICATION
11.1 IDENTIFICATION PROCEDURES CRITERIA — Tentatively identify a sample
component by comparison of its mass spectrum (after background
subtraction) to a reference spectrum in a collection, lise the
following criteria to confirm a tentative identification:
11.1.1 The GC retention time of the sample component must be within
30 s of the time observed for that same compound when a
calibration solution was analyzed.
11.1.2 All ions that are present above 1QS relative abundance in
the mass spectrum of the standard must be present in the
mass spectrum of the sample component and should agree
within absolute 10*. For example, if an ion has a relative
abundance of 30S 1n the standard spectrum, its abundance in
the sample spectrum should be in the range of 20 to 402.
11.1.3 Identification is hampered when sample components are not
resolved chromatographically and produce mass spectra
containing ions contributed by more than one analyte.
Because purgeable organic compounds are relatively small
molecules and produce conparatively simple mass spectra,
this is not a significant problem for most method analytes.
When GC peaks obviously represent more than one sample com-
ponent (i.e., broadened peak with shoulder(s) or valley
-------
between two or more maxima), approoriate analyte spectra and
background spectra can be selected by examining EICPs of
characteristic ions for tentatively identified components. .
When analytes coelute (i.e., only one GC peak is aDparent),
the identification criteria described in Section 11.1.2 can
be met but each analyte spectrum will contain extraneous
ions contributed by the coeluting compound.
11.1.4 Structural Isomers that produce very similar mass spectra
can be explicitly identified only if they have sufficiently
different GC retention times. Acceptable resolution is
achieved if the height of the valley between two isomer
peaks is less than 25X of the sum of the two peak heights.
Otherwise, structural Isomers are identified as Isomeric
pairs.
12. CALCULATIONS
12.1 When an analyte has been Identified, the quantitation of that
analyte should be based on the Integrated abundance from the EICP
of the primary characteristic m/z given 1n Table 4. If the sample
produces an interference for the primary m/z, use a secondary
characteristic m/z to quantltate. Instrument calibration for
secondary Ions 1s performed, as necessary, using the data and
procedures described 1n Sect. 8.2.
12.2 Calculate the concentration In the sample using the calibration
curve or average response factor (RF) determined 1n Sect. 8.2.2 and
Equation 2:
Concentration (uo/L) ¦ ^As^1s^ Equation 2.
(AisJ{RF)
where:
^ > Area of the characteristic m/z for the analyte
to be measured.
A-jj- Area of the characteristic m/z for the Internal
standard.
C-fs« Concentration of the internal standard, in ug/L.
12.3 Report results 1n »g/L. All QC data obtained should be reported
with the sample results.
13. ACCURACY AND PRECISION
13.1 This method was tested in a single laboratory using reagent water
spiked at concentrations between 1 and 5 ug/L. (8) Single operator
precision and accuracy data are presented for some selected
analytes in Table 3.
-------
13.2 Method detection limits have been calculated for some analytes from
data collected in three laboratories. (1,8,9) These data are
sunmarized in Table 1.
14. REFERENCES
1. A. A1ford-Stevens, J.W. Eichelberger, W.L. Budde, "Purgeable Organic
Compounds in Water by Gas Chromatography/ Mass Spectrometry, Method
524." Environmental Monitoring and Support Laboratory, U.S.
Environmental Protection Agency, Cincinnati, Ohio, February 1983.
2. Glaser, J.A., O.L; Foerst, 5.0. McKee, S.A. Quave, and W.L. Budde,
¦Trace Analyses for Wastewaters," Environ. Sci. Techno!., 15, 1426, 1981.
3. "Carcinogens-Working with Carcinogens," Department of Health, Education,
and Welfare, Public Health Service, Center for Disease Control, National
Institute for Occupational Safety and Health, Publication No. 77-206,
August, 1977.
4. "OSHA Safety and Health Standards, General Industry," (29CFR1910),
Occupational Safety and Health Administration, OSHA 2206, (Revised,
January 1976).
5. "Safety in Academic Chemistry Laboratories," American Chemical Society
Publication, Committee on Chemical Safety, 3rd Edition, 1979.
6. Bellar, T.A. and J.J. Llchtenberg, "The Determination of Synthetic
Organic Compounds in Water by Purge and Sequential Trapping Capillary
Column Gas Chromatography,¦ U.S. Environmental Protection Agency,
Environmental Monitoring and Support Laboratory, Cincinnati, Ohio,
January 1985.
7. Budde, W.L. and Eichelberger, J.W., "Performance Tests for the
Evaluation of Computerized Gas Chromatography/Mass Spectrometry
Equipment and Laboratories," EPA-600/4-80-025, U. S. Environmental
Protection Agency, Environmental Monitoring and Support Laboratory,
Cincinnati, OH 45268.
8. Slater, R.W., "Method Detection Limits for 0r1nk1ng Water VolatHes,"
Unpublished report, March 1985.
9. Sorrel 1, R.K., Private Communication, May 1985.
-------
Tafcle 1. CHROMATOGRAPHIC RETENTION TIMES AMO MSTHOO OETECTION
LIMITS (MOL) rOR VOLATILE ORGANIC COWOUNOS ON
WIDE SORE CAPILLARY COLUMNS
RETENTION TIME MOL
ANALYTE (rains) (ug/L)
Column 1^ Column 2&
01chlorodi f 1uoromethane
1.55
0.70
0.10
Chloromethane
1.63
0.73
0.13
Vinyl chloride
1.71
0.79
0.17
Brontome thane
2.01
0.96
0.11
Chloroethane
2.09
1.02
0.10
T p1ch1o rof1uo rometh ane
2.27
1.19
0.08
l,l-01chloroethene
2.89
1.57
0.12
Methylene Chloride
3.60
2.06
0.03
trans-l,2-01chloroethene
3.98
2.36
0.06
1,1-01chloroethane
4.85
2.93
0.04
2,2-01chloropropane
6.01
3.80
0.35
c1s-1,2-01ch1o roeth ene
6.19
3.90
0.12
Chloroform
6.40
4.80
0.03
Bromcchlorcmethane
6.74
4.38
0.04
1,1,1-Trichloroethane
7.27
4.84
0.08
Carton Tetrachloride
7.61
5.26
0.21
1,1-01ch1oropropene
7.68
5.29
c.::
Benzene
8.23
5.67
0.i.*»
1,2-01ch1oroethane
8.40
5.83
0.06
Trlchloroethene
9.59
7.27
0.19
l,2-01chloropropane
10.09
7.66
0.04
Bromod1ch1oromethane
10.59
8.49
0.08
Oibromomethane
10.65
7.93
0.24
Toluene
12.43
10.00
0.11
1,1,2-Trlchloroethane
13.41
11.05
0.10
T etrach1oroethene
13.74
11.15
0.14
1,3-01ch1oropropane
14.04
11.31
0.04
01 bromoch 1 orcmeth ane
14.39
11.85
0.05
1,2-01bromoethane
14.73
11.83
0.06
1-Chlorohexane
15.46
13.29
0.05
Chlorobenzene
15.76
13.01
0.04
1,1,1,2-Tetrach1oroethane
15.94
13.33
0.C5
Ethylbenzene
15.99
13.39
0.06
p-Xylene
16.12
13.69
0.13
tn-Xylene
16.17
13.68
0.05
o-Xylene
17.11
14.52
0.11
Styrene
17.31
14.60
0.04
Bromoform
17.93
14.88
0.12
Isopropylbenzene
18.06
15.46
0.15
1,1,2,2-Tetrach1oroethane
18.72
16.35
0.04
3romobenzene
18.95
15.86
0.03
-------
Table 1. CHROMATOGRAPHIC CONDITIONS AND METHOO OETECTION LIMITS (MDl)
FOR VOLATILE ORGANIC COMPOUNOS
Retention Time* Method Detection Limits (ug/L)
Analyte
(m1n)
Ref. 1
Ref. 8
Ref.
Vinyl chloride
3.8
2
0.31
Oichlorodifluoromethane
3.8
0.33
Methylene chloride
6.4
0.25
0.13
—
T rlchlorof1uoromethane
8.3
—
0.21
—
1,1-Oi ch1oroethene
9.0
0.27
0.19
—
Bromochloromethane
9.3
—
—
—
l,l-01chloroethane
10.1
—
0.17
—
trans-1,2-01ch1oroethene
10.8
1.7
0.19
0.2
Chloroform
11.4
0.20
0.24
0.1
01bromomethane
12.1
—
0.30
—
1,2-01chloroethane
12.1
0.35
0.22
0.2
2,2-01chloropropane
12.7
—
—
—
1,1,1-Tr1chIoroethane
13.4
0.13
0.25
0.2
Carbon tetrachloride
13.7
0.13
0.28
0.2
Bromodichloromethane
14.3
0.29
0.28
0.2
1,2-01ch1oroprop ane
15.7
—
0.17
—
1,1-01chloropropene
16.0
—
—
—
Trlchloroethene
16.5
0.18
0.36
0.2
Benzene
17.0
0.21
0.10
0.2
01bromochloromethane
17.1
0.34
0.30
0.2
1,2-01bromoethane
17.9
—
0.36
—
1,3-01chloropropane
18.4
—
0.10
—
Bromoform
19.8
0.34
0.66
0.5
1,1,2,2-Tetrachloroethane
22 A
0.28
0.41
—
T etrach1oroethene
22.2
0.07
0.29
0.2
Toluene
23.5
0.08
0.12
0.2
Chlorobenzene
24.6
0.09
0.14
0.2
1,2-01bromo-3-ch1oropropane
25.8
—
1.8
—
Bromobenzene
26.7
—
0.12
—
Isopropylbenzene
28.5
—
—
—
n>-Xylene
29.5
—
—
—
Styrene
29.7
1.3
0.20
—
n-Propylbenzene
30.7
—
—
—
o-Xylene
30.9
—
0.20
—
p-Xylene
30.9
0.18
0.13
—
t-8utylbenzene
31.5
—
—
—
-------
Table 1. (Continued)
ANALYTE
RETENTION TIME
(m1ns)
Column 1* Column 2b
MOL
(»g/l)
1.2.3-Trlchloropropane 19.02
n-Propylbenzene 19.06
2-Chlorotoluene 19.34
1,3,5-Trimethylbenzene 19.47
4-Chlorotoluene 19.50
tert-8utylbenzene 20.28
1.2.4-Tr1methylbenzene 20.34
sec-8utylbenzene 20.79
p-Isopropyltoluene 21.20
1.3-01chlorobenzene 21.22
1.4-01chlorobenzene 21.55
n-8utylbenzene 22.22
lt2-01ch1orobenzene 22.52
l,2-01bromo-3-Chloropropane 24.53
1,2,4-Trichlorobenzene 26.55
Hexachlorobutadlene 26.99
Naphthalene 27.17
1,2,3-Trichlorobenzene 27,78
INTERNAL STANDARDS/SURROGATES
Fluorobenzene 8.81
p-8romofluorobenzene 18.63
l,2-0ichlorobenzene-d4 22.26
16.23
16.41
16.42
16.90
16.72
17.57
17.70
18.09
18.52
18.14
18.39
19.49
19.17
21.08
23.08
23.68
23.52
24.18
6.45
15.71
19.14
0.32
0.04
0.04
0.05
0.06
0.14
0.13
0.13
0.12
0.12
0.03
0.11
0.03
0.26
0.04
0.11
0.04
0.03
aColumn 1-60 meter x 0.75mn ID VOCOL capillary. Hold at 10*C for 5 rain,
then program to 160*C at 6*/min.
^Column 2-30 meter x 0.53mm ID 0B-624 mega-bore capillary. Hold at 10*C
for 5 min, then program to 160*C at 6*/m1n.
-------
Table 1. (Continued)
Retention Time* Method Detection Limits (vg/L)"
Analvte (min) Ref. 1 Ref. 8 Ref. 9
2-Chlorotoluene
Hexach1orobutad iene
4-Chlorotoluene
sec-Butyl benzene
1,2-01ch1orobenzene
1,4-01ch1orobenzene
31.5
32.0
32.5
32.5
35.0
35.3
0:3
1.0
2.0
0.1
1 Column Conditions: 2 m x 2 mm ID glass column packed with Carbopack B
(60-80 mesh) coated with IX SP-1000. Carrier gas - Helium at flow of
30 mL/tnin. Column temperature held at 45*C for 3 m1n, then programmed at
8"C/ra1n to 220"C and held until all analytes elute.
2 Not Determined
-------
Table 2. CHROMATOGRAPHIC RETENTION TIMES ANO ME7H00 OETECTION
LIMITS (MOL) FOR VOLATILE ORGANIC CCMPOUNOS ON
.HARROW 80RE CAPILLARY COLUMN
RETENTION TIME
MOL
ANALYTE
(mins)
(ug/L)
Column 3
01ch1orod1fluo romethane
0.38
0.11
Chloromethane
0.97
0.05
Vinyl chloride
1.04
0.04
Bromomethane
1.29
0.06
Chloroethane
1.45
0.02
Tr1chlorof1uoromethane
1.77
0.07
1,1-01chloroethene
2.33
0.05
Methylene Chloride
2.66
0.09
trans-1,2-01ch1oroethene
3.54
0.03
I,1-01chloroethane
4.03
0.03
cis-l,2-01chloroethene
5.07
0.06
2,2-01chloropropane
5.31
0.08
Chloroform
5.55
0.04
Bromoch1oromethane
5.63
0.09
1,1,1-Tr1ch1oroethane
6.76
0.04
1,2-01ch1oroethane
7.00
0.02
l,l-01chloropropene
7.16
0.12
Carbon Tetrachloride
7.41
0.02
Benzene
7.41
0.03
1,2-01chloropropane
8.94
0.02
Trlchloroethene
9.02
0.02
01bromomethane
9.09
0.10
Bromodlch1oromethane
9.34
0.03
Toluene
11.51
0.08
1,1,2-Tr1ch1oroethane
11.99
0.08
1,3-01ch1oropropane
12.48
0.08
01bromoch1oromethane
12.80
0.07
T etrach1oroethene
13.20
0.05
1,2-01bromoethane
13.60
0.10
Chlorobenzene
14.33
0.03
1,1,1,2-Tetrach1oroeth ane
14.73
0.07
Ethylbenzene
14.73
0.03
p-Xylene
15.30
0.06
m-Xylene
15.30
0.03
Brcmof om
15.70
0.20
o-Xylene
15.78
0.06
Styrene
15.78
0.27
1,1,2,2-Tetrach1oroethane
15.78
0.20
1,2,3-Trichloropropane
16.26
0.09
Isopropylbenzene
16.42
0.10
-------
Table 2. (Continued)
RETENTION TIME MDL
ANALYTE (mins) (wg/L)
Bromobenzene
16.42
0.11
2-Chlorotoluene
16.74
0.08
n-Propylbenzene
16.82
0.10
4-Chlorotoluene
16.82
0.06
1,3,5-Tr1methylbenzene
16.99
0.06
tert-8uty1benzene
17.31
0.33
1,2,4-Trfmethylbenzene
17.31
0.09
sec-8uty1benzene
17.47
0.12
1,3-01chlorobenzene
17.47
0.05
p-Isopropy1to1uene
17.63
0.26
1,4-01ch1orobenzene
17.63
0.04
1,2-01ch1orobenzene
17.79
0.05
n-8utylbenzene
17.95
0.10
1,2-01bromo-3-Ch1oropropane
18.03
0.50
1,2,4-Tr1chlorobenzene
18.84
0.20
Naphthalene
19.07
0.10
Hexaclil orobutadl ene
19.24
0.10
1,2,3-Tr1chlorobenzene
19.24
0.14
INTERNAL STANDARD
Fluorobenzene
8.81
6.45
Column - 30 meter x 0.32nin 10 0B-5 capillary with urn film thickness
-------
Mass
50
75
95
96
173
174
175
176
177
Table 2. 3F3 KEY m/z A8UN0ANCS CI ITERIA
m/z Abundance Criteria
15 to 402 of mass 95
30 to 60S of mass 95
Base Peak, 1002 Relative Abundance
5 to 9% of mass 95
< 22 of mass 174
> 502 of mass 95
5 to 92 of mass 174
> 952 but < 1012 of mass 174
5 to 92 of mass 176
-------
Table 3. SINGLE LABORATORY ACCURACY AND PRECISION OATA FOR
VOLATILE ORGANIC COMPOUNOS IN REAGENT WATER
Average
Cone.
Number
Cone.
Standard
Percent
Tested
of
Measured
Deviation
Rel. Std
Analyte
ug/L
Samoles
uo/L
uo/L
Oev.
8enzene
1.0
8
0.97
0.036
3.6
Bromobenzene
1.0
8
0.92
0.042
.4.6
B romod 1 c h 1 o rometh ane
l.S
8
1.43
0.096
6.7
Bromoform
2.5
8
2.36
0.23
9.7
Carbon tetrachloride
1.0
8
0.88
0.098
11.1
Chlorobenzene
1.0
8
1.02
0.047
4.6
Chloroform
1.0
8
1.03
0.086
8.4
01bromoch1oromethane
1.5
8
1.49
0.10
7.0
1,2-01bromo-3-ch1oropropane
3.0
8
3.4
0.63
18.2
1,2-01 bromoethane
1.0
8
0.93
0.13
13.6
Dlbromomethane
1.0
8
0.94
0.11
11.4
1,2-01chlorobenzene
5.0
8
4.95
0.35
7.1
l,4-01chlorobenzene
5.0
8
5.27
0.72
13.6
01chlorodl f1 uoromethane
1.0
8
0.96
0.11
11.9
1,1-01ch1oroethane
1.0
8
1.05
0.060
5.9
1,2-01chloroethane
1.0
8
0.97
0.077
7.9
1,1-01ch1oroethene
1.0
8
1.09
0.066
6.1
trans-1,2-01ch1oroethene
1J3
8
0.98
0.066
6.8
1,2-O1chloropropane
1.0
8
1.01
0.060
5.9
1,3-01ch1oropropane
1.0
8
1.00
0.033
3.4
Methylene chloride
1.0
7
0.99
0.045
4.5
Styrene
1.0
8
1.06
0.066
6.2
1,1,2,2-Tetrachloroethane
1.0
8
1.11
0.14
.12.8
T etrach1oroethene
1.0
8
0.93
0.10
10.9
Toluene
1.0
8
1.05
0.043
4.1
1,1,1-Trichloroethane
1.0
8
1.05
0.093
8.8
Trfchloroethene
1.0
8
0.90
0.12
13.6
Tr1ch1orof1uoromethane
1.0
7
1.09
0.072
6.6
Vinyl chloride
1.0
8
0.98
0.11
10.8
o-Xylene
1.0
8
1.02
0.068
6.7
p-Xylene
1.0
8
1.11
0.047
4.2
-------
Table 3. 3F3 KSY m/z A8UN0ANCE CTITcRIA
Mass m/z Abundance Criteria
50
15 to 402 of mass 95
75
30 to 60% of mass 95
95
Base Peak, 100* Relative Abundance
96
5 to 9% of mass 95
173
< Zi of mass 174
174
> 502 of mass 95
175
5 to 9% of mass 174
176
> 95X but < 1015 of mass 174
177
5 to 9% of mass 175
-------
Table 4. SINGL£ LABORATORY ACCURACY ANO PRECISION OATA FOR
VOLATILE ORGANIC COMPOUNDS IN REAGENT WATER
DETERMINED WITH A WIDE BORE CAPILLARY COLUMN
Analyte
Cone.
Range,
wg/L
Number
of
Samples
Recovery,4
%
Standard
Deviation
of Recovery^
Percen
Rel. S
Oev.
Benzene
0.1 -
10
31
97
5.5
5.7
Bromobenzene
0.1 -
10
30
100
5.5
5.5
8romoch1oromethane
0.5 -
10
24
90
5.7
6.4
Bromodlchloromethane
0.1 -
10
30
95
5.7
6.1
Bromoform
0.5 -
10
18
101
6.4
6.3
Bromome thane
0.5 -
10
18
95
7.8
8.2
n-8utylbenzene
0.5 -
10
18
100
7.6
7.6
sec-Butylbenzene
0.5 -
10
16
100
7.6
7.6
tert-8uty1benzene
0.5 -
10
18
102
7.4
7.3
Carbon tetrachloride
0.5 -
10
24
84
7.4
8.8
Chlorobenzene
0.1 -
10
31
98
5.8
5.9
Chloroethane
0.5 -
10
24
89
8.0
9.0
Chloroform
0.5 -
10
24
90
5.5
6.1
Chioromethane
0.5 -
10
23
93
8.3
8.9
2-Chlorotoluene
0.1 -
10
31
90
5.6
6.2
4-Chlorotoluene
0.1 -
10
31
99-
8.2
8.3
1,2-01bromo-3-chloropropane
0.5 -
10
24
83
16.6
19.9
Dlbromochloromethane
0.1 -
10
31
92
6.5
7.0
1,2-01bromoethane
0.5 -
10
24
102
4.0
3.9
D1bromomethane
0.5 -
10
24
100
5.6
5.6
1,2-Oi ch1orobenzene
0.1 -
10
31
93
5.8
6.2
1,3-01ch1orobenzene
0.5 -
10
24
99
6.8
6.9
1,4-01ch1orobenzene
0.2 -
20
31
103
6.6
6.4
01ch1orod1f1uoromethane
0.5 -
10
18
90
6.9
7.7
1,1—01ch1oroethane
0.5 -
10
24
96
5.1
5.3
1,2-01chloroethane
0.1 -
10
31
95
5.1
5.4
1,1-01chloroethene
0.1 -
10
34
94
6.3
6.7
c1s-l,2 01chloroethene
0.5 -
10
18
101
6.7
6.7
trans-1,2-01ch1oroethene
0.1 -
10
30
93
5.2
5.5
1,2-01chloropropane
0.1 -
10
30
97
5.9
6.1
1,3-01chloropropane
o.r -
10
31
96
5.7
6.0
2,2-01chloropropane
0.5 -
10
12
86
14.6
16.3
1,l-Oi ch1oropropene
0.5 -
10
18
98
8.7
8.9
Ethylbenzene
0.1 -
10
31
99
8.4
8.5
Hexachlorobutadiene
0.5 -
10
18
100
6.8
S.S
Isopropylbenzene
0.5 -
10
16
101
7.7
7.5
p-Isopropy1to1uene
0.1 -
10
23
99
6.7
5.7
-------
Table 4. CHARACTERISTIC MASSES (m/z) FOR PURGEA8LE ORGANICS CQMPCUNOS
Primary Secondary
Characteristic Characteristic
Analvte Ion Ions
Benzene
Bromobenzene
Bromoch1oromethane
Bromod1chlorcmethane
Brorooform
8romome thane
n-8uty1benzene
sec-8utylbenzene
tert-8uty1benzene
Carton tetrachloride
Chlorobenzene
Chloroethane
Chloroform
Chloromethane
2-Chlorotoluene
4-Chlorotoluene
1,2-01bromo-3-Ch1oropropane
01bromoch1oromethane
l,2-01bromoethane
01bromomethane
1.2-01chlorobenzene
1.3-O1ch1orobenzene
114-01ch1orobenzene
01chlorodlfluoromethane
1.1-01chloroethane
1.2-01ch1oro ethane
1.1-01ch1oroethene
c1s-1,2-01ch1oroethene
trans-1,2-01ch1oroethene
1.2-01ch1o roprop ane
1.3-01chloropropane
2,2-01ch1oropropane
1,1-01ch1oropropene
Ethylbenzene
Hexach1orobutad1ene
Isopropylbenzene
D-Isopropy1 to1uene
Methylene chloride
Naphthalene
n-Propylbenzene
Styrene
1,1,1,2-Tetrach1oroethane
78
156
77,158
128
49,130
83
85,127
173
175,254
94
96
91
92,134
105
134
119
91,134
117
119
112
77,114
64
66
83
85
50
52
91
126
91
126
75
155,157
129
127
107
109,188
93
95,174
146
111,148
146
111,148
146
111,148
85
87
63
65,83
62
98
96
61,63
96
61,98
96
61,98
63
112
76
78
77
97
75
110,77
91
106
225
223,227
105
120
119
134,91
84
86,49
128
-
91
120
104
78
131
133,119
-------
Table 4. (Continued)
Cone. Number Standard Percent
Range, of Recovery,a Deviation Rel. Std.
Analyte ug/L Samples X of Recoveryb Qev.
Methylene chloride
0.1
- 10
30
95
5.0
5.3
Naphthalene
0.1
- 100
31
104
8.6
8.2
n-Propylbenzene
0.1
- 10
31
100
5.8
5.8
Styrene
0.1
- 100
39
102
7.3
7.2
1,1,1,2-Tetrach1oroethane
0.5
- 10
24
90
6.1
6.8
1,1,2,2-Tetrachloroethane
0.1
- 10
30
91
5.7
6.3
T etrach1oroethene
0.5
- 10
24
89
6.0
6.8
Toluene
0.5
- 10
18
102
8.1
8.0
1,2,3-Trichlorobenzene
0.5
- 10
18
109
9.4
8.6
1,2,4-Trichlorobenzene
0.5
- 10
18
108
9.0
8.3
1,1,1-Trlchloroethane
0.5
- 10
18
98
7.9
8.1
1,1,2-Trich!oroethane
0.5
- 10
18
104
7.6
7.3
Trichloroethene
0.5
- 10
24
90
6.5
7.3
Tr1ch1orof1uoromethane
0.5
- 10
24
89
7.2
8.1
1,2,3-Trichloropropane
0.5
- 10
16
108
15.6
14.4
1,2,4-Tri methy1benzene
0.5
- 10
18
99
8.0
8.1
1,3,5-Trlmethylbenzene
0.5
- 10
23
92
6.8
7.4
Vinyl chloride
0.5
- 10
18
98
6.5
6.7
o-Xylene
0.1
- 31
18
103
7.4
7.2
nv-Xylene
0.1
- 10
31
97
6.3
6.5
p-Xylene
0.5
- 10
18
104
8.0
7.7
a. Recoveries were calculated using internal standard method. Internal
standard was fluorobenzene.
b. Standard deviation was calculated by pooling data from three levels.
-------
Table 4. (Continued)
Primary Secondary
Analyte 122
1,1,2,2-Tetrachlorcethane 83 131,85
Tetrachloroethene 166 163,129
Toluene 92
1.1.1-Trichloroethane 97 .-9,61
1.1.2-Trlchloroethane 83 97,85
Tr'ichloroethene 95 130,132
Trlchlorofluoromethane 101 103
1.2.3-Trichloropropane 75 77
Vinyl Chloride 62 64
o-Xylene 106 91
ro-Xylene 106 91
p-Xylene 106 91
INTERNAL STAN0AR0S/SURROGATES
Fluorobenzene 96 70
1,2-01chlorobenzene-d4 150 115,152
p-8romofluorobenzene 95 174,176
-------
Table 5. SINGLE LABORATORY ACCURACY ANO PRECISION DATA FOR
VOLATILE ORGANIC COMPOUNOS IN REAGENT WATER
DETERMINED ON A NARROW BORE CAPILLARY COLUMN
Number
a
Percen
Cone,
of
Recovery,
Standard
Rel.
Analyte
ug/L
Samples
S
Deviation
Dev
Benzene
0.1
7
99
6.2
6.3
Sromobenzene
0.5
7
97
7.4
7.6
Bromochloromethane
0.5
7
97
5.8
6.0
Brofflod1 ch 1oromethane
0.1
7
100
4.6
4.6
Bramoforra
0.5
7
101
5.4
5.3
Bromomethane
0.5
7
99
7.1
7.2
n-Butylbenzene
0.5
7
94
6.0
6.4
sec-Butyl benzene
0.5
7
110
7.1
6.5
tert-Butylbenzene
0.5
7
110
2.5
2.3
Carbon tetrachloride
0.1
7
108
6.8
6.3
Chlorobenzene
0.1
7
91
5.8
6.4
Chloroethane
0.1
7
100
5.8
5.8
Chloroform
o-.i
7
105
3.2
3.0
Chloromethane
0.5
7
101
4.7
4.7
2-Chlorotoluene
0.5
7
99
4.6
4*. 6
4-Chlorotoluene
0.5
7
96
7.0
7.3
1,2-01bromo-3-chloropropane
0.5
7
92
10.0
10.9
01bromoch1oromethane
0.1
7
99
5.6
5.7
1,2-01bromoeth ane
0.5
7
97
5.6
5.8
¦01 bromomethane
0.5
7
93
5.6
6.0
1,2-0ichlorobenzene
0.1
7
97
3.5
3.6
I,3-01chlorobenzene
0.1
7
101
6.0
5.9
1,4-01chlorobenzene
0.1
7
106
6.5
6.1
01chlorodifluoromethane
0.1
7
99
8.8
8.9
1,1-01chloroethane
0.5
7
98
6.2
6.3
1,2-01ch1oroethane
0.1
7
100
6.3
6.3
1,1-01ch1o roethene
0.1
7
95
9.0
9.5
c1s-l,2 Olchloroethene
0.1
7
100
3.7
3.7
trans-1,2-01ch1oroethene
0.1
7
98
7.2
7.3
1,2-01ch1oropropane
0.5
7
96
6.0
6.3
1,3-01ch1oroprooane
0.5
7
99
5.8
5.9
2,2-01chloropropane
0.5
7
99
4.9
4.9
1,1-01ch1oropropene
0.5
7
102
7.4
7.3
Ethylbenzene
0.5
7
99
5.2
5.3
Hexachlorobutadi ene
0.5
7
100
6.7
6.7
Isopropylbenzene
0.5
7
102
6.4
6.3
p-Isopropylto1uene
0.5
7
113
13.0
11.5
-------
Table 5. (Continued)
Cone,
Number
a
Percent
of
Recovery,
Standard
Rel. Stc
Anal/te
»9/l
Samples
*
m
Deviation
Oev.
Methylene chloride
0.5
7
97
13.0
13.4
Naphthalene
0.5
7
98
7.2
7.3
n-Propylbenzene
0.5
7
99
6.6
6.7
Styrene
0.5
7
96
19.0
19.8
1,1,1,2-Tetrach1oroethane
0.5
7
100
4.7
4.7
1,1,2,2-Tetrachloroethane
0.5
7
100
12.0
12.0
Tetrach1oroethene
0.1
7
96
5.0
5.2
To1uene
0.5
7
100
5.9
5.9
1,2,3-Tr1ch1orobenzene
0.5
7
102
8.9
8.7
1,2,4-Trichlorobenzene
0.5
7
91
16.0
17.6
1,1,1-Tri chloroeth ane
0.5
7
100
4.0
4.0
1,1,2-Tr i ch1oroeth ane
0.5
7
102
4.9
4.8
Trichloroethene
0.1
7
104
2.0
1.9
Trich1orof1uoromethane
0.1
7
97
4.6
4.7
1,2,3-Trichloropropane
0.5
7
96
6.5
6.8
1,2,4-Trimethylbenzene
0.5
7
96
6.5
6.8
1,3,5-Trimethylbenzene
0.5
7
101
4.2
4.2
Vinyl chloride
0.1
7
104
0.2
0.2
o-Xylene
0.5
7
106
7.5
7.1
rn-Xylene
0.5
7
106
4.6
4.3
p-Xylene
0.5
7
97
6.1
6.3
a. Recoveries were calculated using internal standard method. Internal
standard was fluorobenzene.
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Table 6. CHARACTERISTIC MASSES (m/z) FOR PURGEA8LE ORGANICS COMPOUNOS
Primary Secondary-
Characteristic Characteristic
Analyte Ion Ions
Benzene
Bromobenzene
8romochloromethane
8romodichloromethane
Bromoform
Broraomethane
n-8utylbenzene
sec-8utylbenzene
tert-8uty1benzene
Carbon tetrachloride
Chlorobenzene
Chloroethane
Chloroform
Chloromethane
2-Chlorotoluene
4-Chlorotoluene
1,2-01 bromo-3-Oi 1 oropropane
D1bromoch1oromethane
1,2-01bromoethane
Dibromome thane
1.2-01chlorobenzene •
1.3-01chlorobenzene
1.4-01ch1orobenzene
01chlorodlf1uoromethane
1.1-01chloroethane
1.2-01chloroethane
1.1-01ch1oroethene
cis-l,2-01chloroethene
trans-l,2-01chloroethene
1.2-01chloropropane
1.3-01ch1oropropane
2,2-01ch1oropropane
1,1-0ich1oropropene
Ethylbenzene
Hex ach1orobutad1ene
Isopropylbenzene
p-Isopropyltoluene
Methylene chloride
Naphthalene
n-Propylbenzene
Styrene
1,1,1,2-Tetrachloroethane
73
156
77,158
128
49,130
83
85,127
173
175,254
94
96
91
92,134
105
134
119
91,134
117
119
112
77,114
64
66
83
85
50
52
91
126
91
126
75
155,157
129
127
107
109,188
93
95,174
146
111,148
146
111,148
146
111,148
85
87
63
65,83
62
98
96
61,63
96
61,98
96
61,98
63
112
76
78
77
97
75
110,77
91
106
225
223,227
105
120
119
134,91
84
86,49
128
-
91
120
104
78
131
133,119
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Table 5. (Continued)
Analyte
Primary
Ion
Secondary
Ions
1,1,2,2-Tetrach1oroethane
83
131,85
Tetrach1oroethene
166
168,129
Toluene
92
91
1,2,3-Tr1ch1orobenzene
180
182,145
1,2,4-Trlchlorobenzene
180
182,145
1,1,1-Tr1ch1oroethane
97
99,61
1,1,2-Trlchl oroethane
83
97,85
Trlchloroethene
95
130,132
Trlchlorofluoromethane
101
103
1,2,3-Trichloropropane
75
77
1,2,4-Trlmethylbenzene
105
120
1,3,5-Trimethy1benzene
105
120
Vinyl Chloride
62
64
o-Xylene
106
91
m-Xylene
106
91
p-Xylene
106
91
INTERNAL STANOAROS/SURROGATES
F1uorobenzene
1,2-01ch1orobenzene-d4
p-8rcmofluorobenzene
96
150
95
70
115,152
174,176
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METHOD 524.2. VOLATILE ORGANIC COMPOUNOS IN WATER BY
PURGE ANO TRAP CAPILLARY COLUMN GAS CHROMATOGRAPHY/MASS SPECTROMETRY
(August, 1986)
1. SCOPE AND APPLICATION
1.1 This method is applicable for the determination of various volatile
organic compounds in finished drinking water, raw source water, or
drinking water in any treatment stage. (1) The following compounds
can be determined by this method:
Analyte
Chemical Abstract Services
Reqlstry Number
Benzene
71-43-2
Brcmobenzene
108-86-1
Bromochloromethane
74-97-5
Bromod1ch1oromethane
75-27-4
Bronofonn'
75-25-2
Bromomethane
74-83-9
n-Butylbenzene
104-51-8
sec-8uty1benzene
135-98-8
tert-Buty1 benzene
98-06-6
Carbon tetrachloride
56-23-5
Chlorobenzene
108-90-7
Chloroethane
75-00-3
Chloroform
67-66-3
Chioromethane
74-87-3
2-Chlorotoluene
95-49-8
4-Chlorotoluene
106-43-4
01bromochloromethane
124-48-1
1,2-01bromo-3-chloropropane
96-12-8
1,2-01bromoethane
106-93-4
Dlbrcmomethane
74-95-3
1,2-01ch1orobenzene
95-50-1
1,3-Oichlorobenzene
541-73-1
1,4-01ch1orobenzene
106-46-7
01ch1orodlf1uoromethane
75-71-8
1,1-01ch1oroethane
75-34-3
l,2-01chloroethane
107-06-2
1,1-01ch1oroethene
75-35-4
cis-l,2-0ichloroethene
156-59-4
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Chemical Abstract Services
Analyte
Registry Number
trans-1,2-01ch1oroethene
156-60-5
l,2-01chloropropane
78-37-5
l,3-01chloropropane
142-28-9
2,2-0ich1oropropane
590-20-7
1,1-01ch1oropropene
563-58-6
Ethylbenzene
100-41-4
Hexach1orobutad1ene
87-68-3
Isopropylbenzene
98-82-8
p-Isopropylto!uene
99-87-6
Methylene chloride
75-09-2
Naphthalene
91-20-3
n-Propylbenzene
103-65-1
Styrene
100-42-5
1,1,1,2-Tetrachloroethane
630-20-6
1,1,2,2-Tetrach1oroethane
79-34-5
Tetrachloroethene
127-18-4
Toluene
108-88-3
1,2,3-Trlchlorobenzene
87—61—6
1,2,4-Trichlorobenzene
120-82-1
1,1,1-Trlchloroethane
71-55-6
1,1,2-Tr1ch1oroethane
79-00-5
Trlchloroethene
79-01-6
Trlchlorof1uoromethane
75-69-4
1,2,3-Tr1ch1oropropane
96-18-4
1,2,4-Tr1methylbenzene
95-63-6
1,3,5-Tr1methy1benzene
108-67-8
Vinyl chloride
75-01-4
o-Xylene
95-47-6
in-Xylene
108-38-3
p-Xylene
106-42-3
1.2 Method detection limits (MOLs) (2) are compound dependent and vary
with purging efficiency and concentration. The MOLs for selected
analytes are presented 1n Table 1. The applicable concentration
range of this method 1s compound and instrument dependent but 1s
approximately 0.1 to 200 ug/L. Analytes that are inefficiently
purged from water will not be detected when present at low
concentrations, but they can be measured with acceptable accuracy
and precision when present in sufficient amounts. Determination of
sane geometrical isomers (i.e., xylenes) may Be hampered by
coelutlon.
-------
1.3 This method is recotimended for use only by analysts experienced 1n
the iiieasurenter.t of purgeable crganics at the low ug/L level or by
experienced technicians under the close supervision of a qualified
analyst.
2. SUMMARY OF METHOO
2.1 Highly volatile organic compounds with low water solubility are
extracted (purged) from the sample matrix by bubbling an inert gas
through a 25 mL aqueous sample. Purged sample components are
trapped in a tube containing suitable sorbent materials. When
purging 1s complete, the sorbent tube is heated and backflushed
with helium to desorb trapped sample components. The analytes are
desorbed directly to a large bore capillary or cryofocussed on a
capillary precolumn before being flash evaporated to a narrow bore
capillary for analysis. The column 1s temperature progranmed to
separate the method analytes which are then detected with a mass
spectrometer (MS) Interfaced to the gas chromatograph.
W1de-bore capillary columns generally require a jet separator,
whereas narrow-bore capillaries can be directly Interfaced to the
1on source.
2.2 Tentative Identifications are confirmed by analyzing standards
under the same conditions used for samples and comparing resultant
mass spectra and GC retention times. Each identified component 1s
measured by relating the MS response for an appropriate selected
1on produced by that compound to the MS response for another ion
produced by a compound that 1s used as an internal standard.
3. INTERFERENCES
3.1 During analysis, major contaminant sources are volatile materials
1n the laboratory and Impurities 1n the inert purging gas and 1n
the sorbent trap. The use of non-polytetrafluoroethylene (PTFE)
plastic tubing, non-PTFE thread sealants, or flow controllers with
rubber components in the purging device should be avoided since
such materials out-gas organic compounds which will be concentrated
in the trap during the purge operation. Analyses of laboratory
reagent blanks (Sect. 9.1.3) provide information about tne presence
of contaminants. When potential interfering peaks are noted in
laboratory reagent blanks, the analyst should change the ourge gas
source and regenerate the molecular sieve ourge gas filter (F1g.
1). Subtracting blank values from samole results is r.ct permitted.
-------
3.2 Interfering contamination may occur when a sample containing low
concentrations of volatile organic compounds is analyzed
inmediately after a sample containing relatively high
concentrations of volatile organic compounds. A preventive
technique 1s between-sample rinsing of the purging apparatus and
sample syringes with two portions of reagent water. After analysis
of a sample containing high concentrations of volatile organic
compounds, one or more laboratory reagent blanks should be analyzed
to check for cross contamination. For samples containing large
amounts of water soluble materials, suspended solids, high boiling
compounds or high levels of compounds being determined, 1t may be
necessary to wash out the purging device with a soap solution,
rinse it with reagent water, and then dry 1t in an oven at 105 "C
between analyses.
3.3 Special precautions must be taken to analyze for methylene
chloride. The analytical and sample storage area should be
Isolated from all atmospheric sources of methylene chloride,
otherwise random background levels will result. Since methylene
chloride will permeate through PTFE tubing, all gas chromatography
carrier gas lines and purge gas plumbing should be constructed from
stainless steel or copper tubing. Laboratory clothing worn by the
analyst should be clean since clothing previously exposed to
methylene chloride fumes during cannon liquid/liquid extraction
procedures can contribute to sample contamination.
4. SAFETY
4.1 The toxicity or carcinogenicity of chemicals used In this method
has not been precisely defined; each chemical should be treated as
a potential health hazard, and exposure to these chemicals should
be minimized. Each laboratory 1s responsible for maintaining
awareness of OSHA regulations regarding safe handling of chemicals
used 1n this method. Additional references to laboratory safety
are available (3-5) for the information of the analyst.
4.2 The following method analytes have been tentatively classified as
known or suspected human or raamnallan carci nc: benzene, carbon
tetrachloride, l,4-d1chlorobenzene, l,2-d1chlcr3:r.ane, hexachloro-
butadlene, 1,1,2,2-tetrachloroethane, 1,1,2-trfcMoroethane,
chloroform, l,2-d1bromoethane, tetrachloroethene, trichloroethene,
and vinyl chloride. Pure standard materials and stock standard
solutions of these compounds should be handled in a hood. A
NIOSH/MESA approved toxic gas respirator should be worn when the
analyst handles high concentrations of these toxic compounds.
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5« APPARATUS and equipment
5.1 SAMPLE CONTAINERS - 60-mL to 120-mL screw cap vials (Pierce #19832
or equivalent) each equipped with a PTFE-faced silicone septum
(Pierce #12718 or equivalent). Prior to use, wash vials and septa
with detergent and rinse with tap and distilled water. Allow the
vials and septa to air dry at room temperature, place in a 105"C
oven for one hour, then remove and allow to cool in an area known
to be free of organics.
5.2 PURGE ANO TRAP SYSTEM - The purge and trap system consists of three
separate pieces of equipment: purging device, trap, and desorber.
Systems are coninercially available from several sources that meet
all of the following specifications.
5.2.1 The all glass purging device (F1g. 1) must be designed to
accept 25-mL samples with a water column at least 5 cm
deep. Gaseous volumes above the sample must be kept to a
minimum (< 15mL) to eliminate dead volume effects. A glass
frit should be Installed at the base of the sample chamber
so the purge gas passes through the water column as finely
divided bubbles with a diameter of < 3 ran at the origin.
Needle spargers may be used, however, the purge gas must be
Introduced at a point ^ 5 ran from the base of the water
column. ""
5.2.2 The trap (F1g. 2) must be at least 25 cm long and have an
Inside diameter of at least 0.105 1n. Starting from the
Inlet, the trap should contain 1.0 cm of methyl silicone
coated packing and the following amounts of adsorbents: 1/3
of 2,6-d1phenylene oxide polymer, 1/3 of silica gel, and 1/3
of coconut charcoal. Before^Initial use, the trap should be
conditioned overnight at 180*C by backflushing with an inert
gas flow of at least 20 mL/m1n. Vent the trap effluent to
the room, not to the analytical column. Prior to daily use,
the trap should be conditioned for 10 minutes at 180*C with
backflushing. The trap may be vented to the analytical
column during dally conditioning; however, the column must
be run through the temperature program prior to analysis of
sauries.
5.2.3 The use of the methyl silicone coated packing is
recommended, but not mandatory. The packing serves a dual
purpose of protecting the adsorbent from aerosols, and also
of Insuring that the adsorbent is fully enclosed within the
heated zone of the trap thus eliminating potential cold
spots. Alternatively, silanlzed glass wool may be used as a
spacer at the trap inlet.
-------
5.2.4 The desorber must be capable of rapidly heating the trap to
ISO'C. The polvmer section of the trap should not be heated
higher than 200 C or the life exoectancy of the trap will
decrease. Trap failure is characterized by a pressure drop
1n excess of 3 pounds per square inch across the trap during
purging or by poor bromoform sensitivities. The desorber
design illustrated in Fig. 2 meets these criteria.
5.2.5 Figures 3 and 4 show typical flow patterns for the
purge-sorb and desorti modes.
GAS CHROMATOGRAPHY/MASS SPECTROMETER/OATA SYSTEM (GC/MS/DS)
5.3.1 "!"¦"» GC must be capable of temperature programnlng and should
be equipped with variable-constant differential flow
controllers so that the column flow rate will remain
constant throughout desorptlon and temperature program
operation. The column oven must be cooled to <30"C,
therefore, a subamblent oven controller 1s required. The GC
usually 1s Interfaced to the MS with an all-glass enrichment
device and an all-glass transfer line, but any enrichment
device or transfer line can be used 1f the performance
specifications described 1n Sect. 9.2.5 can be achieved.
5.3.2 Gas Chromatographic Column 1 - 60m long x 0.75mm ID V0C01
(Supelco, Inc.) wide-bore capillary column with 1.5 ym film
thickness. The flow rate of helium carrier gas 1s
established at 15 mL/m1n. The column temperature 1s#held
for 5 minutes at 10*C, then programmed to 160*C at 6*C/m1n,
and held until all expected compounds have eluted. A sample
chromatogram obtained with this column 1s presented in Fig.
5. This column was used to develop the method performance
statements 1n Section 13.
5.3.3 Gas Chromatographic Column 2 - 30m long x 0.53mm ID OB-624
Mega-3ore (J&W Scientific, Inc.) column with 3 um film
thickness. Helium carrier gas flow 1s 15 mL/mln. The
column temperature 1s held for 5 minutes at 10*C, then
programmed to 160"C at 6"C/min. A sample chromatogram
obtained with this column 1s presented in F1g. 6.
5.3.4 Gas Chromatographic Column 3 - 30 meter long x 0.32mm ID
fused silica capillary column coated with Ourabond DB-5 (J&W
Scientific, Inc.) with a lmn film thickness. Helium carrier
gas flow 1s 4.0 mL/m1n. The column 1s maintained at 10"C
for 5 nrins, then programmed at 6*/min for 10 min than
15"/rain for 5 m1n to 145"C. A sample chromatogram obtained
with this column is presented in Fig. 7.
-------
5.3.S Mass spectral data are obtained with electron-impact
ionization at a nominal electron energy of 70 eV. The mass
spectrometer must be capable of scanning from 3S to 300 am
every 2s or less and must produce a mass spectrum that meets
all criteria in Table 3 when 50 ng or less of
4-bromofluorobenzene is introduced into the GC. • To ensure
sufficient precision of mass spectral data, the desirable MS
scan rate allows acquisition of at least five spectra while
a sample component elutes from the GC.
5.3.5 An Interfaced data system (OS) is required to acquire,
store, reduce and output mass spectral data. The computer
software must allow searching any GC/MS data file for 1ons
of a specific mass and plotting Ion abundances versus time
or scan number. This type of plot 1s defined as an
extracted ion current profile (EICP). Software must also
allow Integrating the abundance 1n any EICP between
specified time or scan number Unrits.
5.4 CAPILLARY INTERFACE - The device Interfaces the purge and trap
concentrator to the capillary gas chromatograph. The interface
condenses the desorbed sample components and focuses them into a
narrow band on an uncoated fused silica capillary pre-column. When
the Interface 1s flash heated the sample 1s transferred to the
analytical capillary column.
5.4.1 Under a stream of liquid nitrogen, the temperature of the
fused silica 1n the Interface 1s maintained at -150#C during
the cryofocusing step. After the desorption period, the
interface must be capable of rapid heating to *250*C 1n 15
sec. or less to complete the transfer of analytes.
5.5 SYRINGE ANQ SYRINGE VALVES
5.5.1 Two 25-mL glass hypodermic syringes with Luer-Lok tip.
5.5.2 Three 2-«ay syringe valves with Luer ends.
5.5.3 Micro syringes - 10, 25, 100 uL.
5.5.4 Syringes - 0.5, -1.0, and 5-mL, gas tight with shut-off valve.
5.6 MISCELLANEOUS
5.6.1 Standard solution storage containers - 15^tL bottles with
PTFE-lined screw caps.
-------
6. REAGENTS A,NO CONSUMABLE MATERIALS
6.1 TRAP PACXING MATERIALS
6.1.1 2,6-0iphenylene oxide polymer, 60/30 .mesh, chrcmatograohic
grade (Tenax GC or equivalent).
6.1.2 Methyl silicone packing (optional) - OV-1 (3%) on Chromo-
sorb W, 60/30 mesh, or equivalent.
6.1.3 Silica gel - 35/60 mesh, Davison, grade 15 or equivalent.
6.1.4 Coconut charcoal - Prepare from Barnebey Cheney, CA-530-26
lot #f*-2649 by crushing through 26 mesh screen.
6.2 .REAGENTS
6.2.1 Methanol - Demonstrated to be free of analytes.
6.2.2 Reagent water - Prepare reagent water by passing tap water
through a filter bed containing about 0.5 kg of activated
carbon, by using a water purification system, or by boiling
distilled water for 15 min followed by a 1-h purge with
Inert gas while the water temperature is held at 90*C.
Store 1n clean, narrow-mouth bottles with PTFE-I1ned septa
and screw caps.
6.2.3 Hydrochloric acid (1+1) - Carefully add measured volume of
conc. HC1 to equal volume of reagent water.
6.2.4 Vinyl chloride - 99.9i pure vinyl chloride is available from
Ideal 6as Products, Inc., Edison, New Jersey and from
Matheson, East Rutherford, New Jersey. Certified mixtures
of vinyl chloride in nitrogen at 1.0 and 10.0 ppm (v/v) are
available from several sources.
6.3 STANDARO STOCK SOLUTIONS - These solutions may be purchased as
certified solutions or prepared from pure standard materials using
the following procedures:
6.3.1 Place about 9.8 ni. of methanol into a 10-mL ground-^lass
stoppered volumetric flask. Allow the flask to stand,
unstoppered, for about 10 min or until all alcohol-wetted
surfaces have dried and weigh to the nearest 0.1 mg.
-------
6.3.2 If the analyte 1s a liquid at room temperature, use a IOO-uL
syringe and insnediately add two or more drops of reference
standard to the flask. Be sure that the reference standard
falls directly into the alcohol without contacting the neck
of the flask. If the analyte is a gas at room temperature,
fill a 5-mL valved gas-tight syringe with the standard to
the 5.0-mL mark, lower the needle to 5 mm above the methanol
meniscus, and slowly inject the standard Into the neck area
of the flask. The gas will rapidly dissolve in the methanol.
6.3.3 Reweigh, dilute to volume, stopper, then mix by inverting
the flask several times. Calculate the concentration in
micrograms per microliter from the net gain 1n weight. When
compound purity 1s certified at 96X or greater, the weight
can be used without correction to calculate the
concentration of the stock standard.
6.3.4 Store stock standard solutions 1n 15-mL bottles equipped
with PTFE-Hned screw caps. Methanol solutions prepared
from Hquid^analytes are stable for at least four weeks when
stored at 4"C. Methanol solutions prepared from gaseous
analytes are not stable for more than one week when stored
at <0*C; at room temperature, they must be discarded after
one day.
6.4 SECONOARY DILUTION STANDAftOS - Use standard stock solutions to
prepare secondary dilution standard solutions that contain the
analytes in methanol. The secondary dilution standards should be
prepared at concentrations that can be easily diluted to prepare
aqueous calibration solutions (Sect. 8.1) that will bracket the
working concentration range. Store the secondary dilution standard
solutions with minimal headspace and check frequently for signs of
deterioration or evaporation, especially just before preparing
calibration solutions from them. Storage times described for stock
standard solutions 1n Sect. 6.3.4 also apply to secondary dilution
standard solutions.
6.5 INTERNAL STANOARO SPIKING SOLUTION — Prepare a spiking solution
containing fluorooenzene, and l,2-dichlorooenzene-d4 in methanol
using the procedures described in Sect. 6.3 and 6.4. It is
recomnended that the secondary dilution standard be prepared at a
concentration of 25 yg/mL of each internal standard compound. The
addition of 10 uL of such a standard to 25.0 -m. of sample or
calibration standard be ecuivaient to 10 ua/L.
6.6 BF3 STANDARO — Prepare l :=-u»;/*nL solution of brcmof1uorobenze^e
in methanol.
-------
6.7 LABORATORY QUALITY CONTROL STANOARO CONCENTRATE - Using standard
stock solutions, prepare a solution containing each analyte of
interest at a concentration of £00 times the MCL in methanol.
7. SAMPLE COLLECTION, PRESERVATION, ANO STORAGE
7.1 SAMPLE COLLECTION
7.1.1 Collect all samples in duplicate. Fill sample bottles to
overflowing. No air bubbles should pass through the sample
as the bottle is filled, or be trapped in the sample when
the bottle 1s sealed.
7.1.2 When sampling from a water tap, open the tap and allow the
system to flush until the water temperature has stabilized
(usually about 10 m1n). Adjust the flow to about 500 mL/min
and collect duplicate samples from the flowing stream.
7.1.3 When sampling from an open body of water, fill a 1-quart
wide-mouth bottle or 1-liter beaker with sample from a
representative area, and carefully fill duplicate sample
bottles from the container.
7.2 SAMPLE PRESERVATION
7.2.1 Adjust the pH of the duplicate samples to <2 by carefully
adding one drop of 1:1 HC1 for each 20 mL of sample
volume.(6) Seal the sample bottles, PFTE-face down, and
shake vigorously for one minute.
7.2.2 The samples must be chilled to 4"C on the day of collection
and maintained at that temperature until analysis. Field
samples that will not be received at the laboratory on the
day of collection must be packaged for shlpment^with
sufficient Ice to ensure that they will be at 4"C on arrival
at the laboratory.
7.3 SAMPLE STORAGE
7.3.1 Store samples at 4'C until analysis. The sample stcrige
area must be free of organic solvent vapors.
7.3.2 Analyze all samoles within 14 days of collection. Samples
not analyzed within this period must be discarded and
replaced.
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8. calibration and standardization
8.1 PREPARATION OF CALIBRATION STANOAROS
8.1.1 A set of at least five calibration standards containing the
method analytes is needed. One calibration standard should
contain each analyte at a concentration approaching but
greater than the method detection limit (Table 1) for that
compound; the other calibration standards should contain
analytes at concentrations that define the range of the
method.
8.1.2 To prepare a calibration standard, add an appropriate volume
of a secondary dilution standard solution to an aliquot of
reagent water 1n a volumetric flask. Use a mlcrosyrlnge and
rapidly inject the alcoholic standard Into the expanded area
of the filled volumetric flask. Remove the needle as
quickly as possible after Injection. Mix by Inverting the
flask three times only. Discard the contents contained 1n
the neck of the flask. Aqueous standards are not stable and
should be discarded after one hour unless sealed and stored
as described 1n Sect. 7.2.
8.2 CALIBRATION
8.2.1 After meeting the BFB criteria 1n Sect. 10.1, analyze each
calibration standard according to Sect. 10, adding 10 uL of
Internal standard spiking solution directly to the syringe.
For each analyte, select a significant characteristic ion.
When feasible, use the most intense ion in the mass
spectrum; when a less intense 1on 1s more characteristic and
sufficiently Intense to provide necessary sensitivity, use
that 1on to avoid possible Interferences. Tabulate area
response of the characteristic m/z versus the concentration
for each analyte and Internal standard. Calculate response
factors (RF) for each analyte using Equation 1:
RF - (V Equation 1
where:
As ¦ Area of the characteristic m/z for the analyte to be
measured;
Ais • Area of the characteristic m/z for the internal
standard;
-------
Cis ¦ Concentration of the internal standard, in ug/l.
Cs a Concentration of the analyte to be measured, in ug/l.
The choice of which internal standard to use for an analyte
1s left to the analyst.
8.2.2 Prepare a calibration curve for each analyte.
Alternatively, 1f the RF for an analyte is :nstant (less
than 10S RSO) over the working range, the average RF can be
used for that analyte.
8.2.3 The working calibration curve or average response factor
must be verified on each working day by the measurement of
one or more calibration standards. If the quantitation ion
area for any analyte varies from the response determined for
that standard concentration from the calibration curve or
average RF established 1n Sect. 8.2.2 by more than *202,
repeat steps 8.2.1 and 8.2.2.
8.2.4 Calibration for vinyl chloride using a -**ed gaseous
mixture of vinyl chloride 1n nitrogen can oe accomplished by
the following steps.
8.2.4.1 Fill the purging device with 25.0 mL of reagent
water or aqueous calibration standard.
8.2.4.2 Start to purge the aqueous mixture. Inject a known
volume (between 100 and 2000 vL) of the calibration
gas (at room temperature) directly Into the purging
device with a gas tight syringe. Slowly Inject the
gaseous sample through a septum seal at the top of
the purging device at 2000 ul/rain. Oo not Inject
the standard through the aqueous sample inlet
needle. Inject the gaseous standard before five min
of the 11-flrfn purge time have elapseo.
8.2.4.3 Oetermine the aqueous equivalent concentration of
vinyl chloride standard, in ug/L, injected with the
equation:
S-- 0.102 (C)(V) Equation 2
where S ¦ Aqueous equivalent concentration
of vinyl chloride standard in ug/L;
C ¦ Concentration of gaseous standard in ppm;
V ¦ Volume of standard injected in milli-
liters.
-------
9. QUALITY CONTROL
9.1 Each laboratory that uses this method is required to operate a
formal quality control program. The minimum requirements of this
program consist of an initial demonstration of laboratory cap-
ability and an ongoing analysis of spiked samples to evaluate and
document data quality. The laboratory must maintain records to
document the quality of data that 1s generated. Ongoing data
quality checks are compared with established performance criteria
to determine if the results of analyses meet the performance
characteristics of the method. A quality control check standard
must be analyzed to confirm that the measurements were performed in
an in-control mode of operation.
9.1.1 The analyst must make an initial, one-time, demonstration of
the ability to generate acceptable accuracy and precision
with this method. This ability 1s established as described
1n Section 9.2.
9.1.2 In recognition of advances that are occurring in chromato-
graphy, the analyst 1s permitted certain options (detailed
in Section 10.2.2) to improve the separations or lower the
cost of measurements. Each time such a modification 1s made
to the method, the analyst 1s required to repeat the
procedure in Section 9.2.
9.1.3 Each day, the analyst must analyze a reagent water blank to
demonstrate that interferences from the analytical system
are under control.
9.1.4 The laboratory must, on an ongoing basis, demonstrate
through the analyses of quality control check standards that
the operation of the measurement system 1s 1n control. This
procedure is described 1n Section 9.3. The frequency of the
check standard analyses 1s equivalent to 102 of all samples
analyzed but at least two samples per month.
9.1.5 On a weekly basis, the laboratory must demonstrate the
ability to analyze low level samples. A procedure for low
level check samples is described in Section 9.4.
9.1.6 The laboratory must maintain performance records to document
the quality of data that 1s generated. This procedure is
described in Section 9.5.
9.2 To establish the ability to generate acceptable accuracy and
precision, the analyst must perform the following operations.
-------
9.2.1 A quality control (QC) check sample concentrate is required
containing each regulated analyte, and any additional
analyte wnich is to be reported, at a concentration of 500
times the MCI or 5 ug/mL, whichever is smaller, in
methanol. The QC check sample must be prepared by the
laboratory using stock standards prepared independently from
those used for calibration.
9.2.2 Analyze seven 25-mL QC check samples at 1/5 MCt or 2 ug/L
according to the method beginning 1n Sect. 10. Each sample
is produced by Injecting 10 uL of QC check sample
concentrate into 25 mL of reagent water in a glass syringe
through the syringe valve.
9.2.3 Calculate the average recovery (7) in ug/L, and the standard
deviation of the recovery (s) 1n yg/L for each analyte using
the seven results. Calculate the MOL for each analyte as
specified 1n Ref. 2. The calculated MOL must be less than
the spike level.
9.2.4 For each analyte, (7) must be between 90% and 1105 of the
true value. Additionally, s must be ^ 35% of 7. If s and 7
for all analytes meet the criteria, the system performance
1s acceptable and analysis of actual samples can begin. If
any s exceeds the precision limit or any 7 falls outside the
range for accuracy, the system performance is unacceptable
for that analyte.
NOTE: The large number of analytes present a substantial
probability that one or more will fall at least one of the
acceptance criteria when all analytes are analyzed.
9.2.5 When one or more of the analytes tested fail at least one of
the acceptance criteria, the analyst must proceed according
to Section 9.2.2 only for the analytes which failed the test.
The laboratory must demonstrate on a regular basis as outlined 1n
Section 9.1.4 that the measurement system 1s 1n control by
analyzing a quality control check sample for all analytes of
interest at the MCL or 10 ug/L, whichever 1s smaller.
9.3.1 Prepare a QC check standard by adding 50 uL of QC check
sample concentrate to 25 ni. of regent water 1n a glass
syringe.
9.3.2 Analyze the QC check according to Section 10, and calculate
the recovery for each analyte. The recovery must be between
60% and 140% of the expected value.
-------
9.3.3 If the recovery for any analyte falls outside the designated
range, the analyte has failed the acceptance criteria. A
check standard containing each analyte that failed must be-
re-analyzed.
9.4 On a weekly basis, the laboratory must demonstrate the ability to
analyze low level samples.
9.4.1 Prepare a low level check sample by spiking 10 UL of QC
check sample concentrate to 25 iri. of reagent water and
analyze according to the method in Sect. 10.
9.4.2 For each analyte, the recovery must be between 60S and 140S
of the expected value.
9.4.3 When one or more analytes fail the test, the analyst must
repeat the test only for those analytes which failed to meet
the criteria. • Repeated failure, however, win confirm a
general problem with the measurement system. If this
occurs, locate and correct the source of the problem and
repeat the test for all compounds of interest beginning with
9.4.1.
9.5 It 1s recotmtended that the laboratory adopt additional quality
assurance practices for use with this method. The specific
practices that are most productive depend upon the needs of the
laboratory and the nature of the samples. Field duplicates may be
analyzed to assess the precision of the environmental measurements.
Whenever possible, the laboratory should analyze standard reference
materials and participate in relevant performance evaluation
studies.
PROCEDURE
10.1 OAILY GC/MS PERFORMANCE TESTS
10.1.1 At the beginning of each day that analyses are to be
performed, the GC/MS system must be checked to see if
acceptable performance criteria are achieved for BF3 (7).
The performance test must be passed before any samples,
blanks, or standards are analyzed.
10.1.2 At the beginning of each day. Inject 2 uL (50 ng) of BFB
solution directly on the column. Alternatively, add 2 ul of
BFB solution to 25.0 mL of reagent water or calibration
standard and analyze the solution according to Sect. 10.
Obtain a background-corrected mass spectrum of 8FB and
confirm that all the key m/z criteria in Table 3 are
achieved. If all the criteria are not achieved, the analyst
must retune the mass spectrometer and repeat the test until
all criteria are achieved.
-------
10.2 INITIAL C0N0ITI0NS
10.2.1 Acquire GC/MS data for performance tests, standards and
samples using the following instrumental analytes:
Electron Energy:
Mass Range:
Scan Time:
70 V (nominal)
35 to 300 amu
To give at least 5 scans per peak but
not to exceed 2 s per scan.
10.2.2 The operating conditions for the gas chromatograph are
summarized under Sections 5.3.2 through 5.3.4.. Tables 1
and 2 11st the retention times and MOL that can be achieved
under these conditions. Examples of separations achieved
with this method are shown 1n Figures 5-7. Other columns or
chromatographic conditions may be used 1f the requirements
of Section 9 are met.
10.3 SAMPLE INTRODUCTION AND PURGING
10.3.1 Adjust the purge gas (nitrogen or helium) flow rate to 40
mL/m1n. Attach the trap Inlet to the purging device and
open the syringe valve on the purging device.
10.3.2 Remove the plungers front two 25-mL syringes and attach a
closed syringe valve to each. Warm the sample to room
temperature, open the sample (or standard) bottle, and
carefully pour the sample into one of the syringe barrels to
Just short of overflowing. Replace the syringe plunger,
Invert the syringe, and compress the sample, "r^n the
syringe valve and vent any residual air whlit _;-'ng the
sample volume to 25.0 mL. Add 10 uL of the 1n
standard spiking solution (Section 6.5) to the .
through the syringe valve. Close the valve. Fill tne
second syringe 1n an identical manner from the same sample
bottle. Reserve this second syringe for a reanalysis if
necessary.
10.3.3 Attach the sample syringe valve to the syringe valve on the
purging device. 8e sure that the trap 1s cooler than 25*C,
then open the sample syringe valve and inject the sample
Into the purging chamber. Close both valves and Initiate
purging. Purge the sample for 11.0 * 0.1 m1n at ambient
temperature (F1g. 3).
10.4 SAMPLE OESORPTIGN - The mode of sample desorptlon is determined by
the type of capillary column employed for the analysis. When using
a wide-bore capillary column, follow the desorption conditions of
Sect. 10.4.1. The conditions for using narrow bore columns is
described in Sect. 10.4.2.
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10.4.1 Sample Oesorption for wide-Sore Capillary Column
Under most conditions, this type of column must be
interfaced to the »MS through an all-glass jet separator.
10.4.1.1 After the 11-min purge, attach the trap to the
chromatography adjust the purge and trap system to
the desorb mode (Fig. 4) and Initiate the
temperature program sequence of the gas
chromatograph and start data acquisition.
Introduce the trapped materials to the GC column by
rapidly heating the trap to 180"C while
backflushlng the trap with an inert gas at 15
mL/nrfn for 4.0 * 0.1 min. While the extracted
sample 1s being Introduced Into the gas
chromatograph, empty the purging device using the
sample syringe and wash the chamber with two 25-mL
flushes of reagent water. After the purging device
has been emptied, leave the syringe valve open to
allow the purge gas to vent through the sample
Introduction needle.
10.4.1.2 Gas Chromatography - Hold the column temperature at
10#C for 5 rain, then program at 6"C/m1n to 160"C
and hold until all analytes elute.
10.4.1.3 Trap Reconditioning - After desorbing the sample
for 4 min, recondition the trap by returning the
purge and trap system to the purge mode. Wait 15
s, then close the syringe valve on the purging
device to begin ga£ flow through the#trap.
Maintain the trap temperature at 180*C. After
approximately 7 rain, turn off the trap heater and
open the syringe valve to stop the gas flow through
the trap. When the trap 1s cool, the next sample
can be analyzed.
10.4.2 Sample Oesorption for Narrow-8ore Capillary Column
Under normal operating conditions, most narrow-bore
capillary columns can be interfaced directly to the MS
without a jet separator.
10.4.2.1 Sample Oesorption - After the 11 min purge, attach
the trap to the cryogenically cooled interface at
-150*C and adjust the purge and trap system to the
desorb mode (F1g. 4). Introduce the trapped
materials to the interface by rapidly heating the
trap to 180*C while backflushing the trap with an
-------
inert gas at 4 mL/min for 3.0 * 0.1 m1n. While the
extracted sample is being introduced into the
interface, empty the purging device using the
sample syringe and rinse the chamber witn two 25-mL
flushes of reagent water. After the purging device
has been emptied, leave the syringe valve open to
allow the purge gas to vent through the sample
Introduction needle. After desorbing for 5 urin,
flash heat the Interface to ESO'C and quickly
introduce the sample on the chromatographic
column. Start the temperature program sequence,
and Initiate data acquisition.
10.4.2.2 Gas Chromatography - Hold the column temperature at
10'C for 5 min, then program at 6*C/m1n to 7Q*C and
then at 15"/rain to 145*C.
10.3.2.3 Trap Reconditioning - After desorbing the sample
for 5 m1n, recondition the trap by returning the
purge and trap system to the purge mode. Wait 15
s, then close the syringe valve on the purging
device to begin gas flow through the^trap.
Maintain the trap temperature at 180"C. After
approximately 15 m1n, turn off the trap heater and
open the syringe valve to stop the gas flow through
the trap. When the trap 1s cool, the next sample
can be analyzed.
10.5 TERMINATION OF DATA ACQUISITION - When sample components have
eluted from the GC, terminate MS data acquisition and store data
files on the data system storage device. Use appropriate data
output software to display full range mass spectra and appropriate
EICPs. If any 1on abundance exceeds the system working range,
dilute the sample aliquot In the second syringe with reagent water
and analyze the diluted aliquot.
QUALITATIVE IDENTIFICATION
11.1 IDENTIFICATION PROCEDURES CRITERIA — Tentatively identify a sample
component by comparison of its mass spectrum (after background
subtraction) to a reference spectrum in a collection. Use the
following criteria to confirm a tentative identification:
11.1.1 The GC retention time of the sample component must be within
10 s of the time observed for that same compound when a
calibration solution was analyzed.
11.1.2 All ions that are present above 105 relative abundance in
the mass spectrum of the standard inust be present in the
-------
mass spectrum of the sample component and should agree
within absolute 105. For example, if an ion has a relative
abundance of 305 in the standard spectrum, its abundance in
the sample spectrum should be in the range of 20 to 405.
11.1.3 Identification 1s hampered when sample components are not
resolved chromatographically and produce mass spectra
containing 1ons contributed by more than one analyte.
Because purgeable organic compounds are relatively small
molecules and produce comparatively simple mass spectra,
this 1s not a significant problem for most method analytes.
When GC peaks obviously represent more than one sample com-
ponent (i.e., broadened peak with shoulder(s) or valley
between two or more maxima), appropriate analyte spectra and
background spectra can be selected by examining EICPs of
characteristic 1ons for tentatively Identified components.
When analytes coelute (I.e., only one GC peak 1s apparent),
the Identification criteria described 1n Section 11.1.2 can
be met but each analyte spectrum will contain extraneous
1ons contributed by the coeluting compound.
11.1.4 Structural Isomers that produce very similar mass spectra
can be explicitly Identified only 1f they have sufficiently
different GC retention times. Acceptable resolution Is
achieved 1f the height of the valley between two Isomer
peaks 1s less than 255 of the sum of the two peak heights.
Otherwise, structural Isomers are identified as Isomeric
pairs.
CALCULATIONS
12.1 When an analyte has been identified, the quantitation of that
analyte should be based on the Integrated abundance from the EICP
of the primary characteristic m/z given 1n Table 6. If the sample
produces an Interference for the primary m/z, use a secondary
characteristic m/z to quantltate. Instrument calibration for
secondary 1ons 1s performed, as necessary, using the data and
procedures described 1n Sect. 8.2.
12.2 Calculate the concentration 1n the sample using the calibration
curve or average response factor (RF) determined in Sect. 8.2.2 and
Equation 3:
Concentration (ug/L) ¦
(A1sHRF)
Equation 3.
-------
where:
As ¦ Area of the characteristic m/z for the analyte
to be measured;
A1s^ Area 0-ff the characteristic m/z for the internal
standard;
C-js— Concentration of the internal standard, in ug/L.
12.3 Report results in ug/L. All qc data obtained should be reported
with the sample results.
13. ACCURACY ANO PRECISION
13.1 This method has been tested 1n a single laboratory using spiked
reagent water. Using a w1de-bore capillary column, water was
spiked at concentrations between 0.5 and 10 ug/L (8). Single
laboratory accuracy and precision data are presented for the method
analytes in Table 4. Calculated MOLs are presented 1n Table 1.
13.2 The method was tested using reagent water spike at 0.1 to 0.5 ug/L
and analyzed on a cryofocused narrow-bore column. The accuracy and
precision data for these compounds are presented 1n Table 5 (9).
MOL values were also calculated from these data ana are presented
1n Table 2.
14. REFERENCES
1. A. A1ford-Stevens, J.W. Elchelberger, W.L. 8udde, "Purgeable Organic
Compounds in Water by Gas Chromatography/Mass Spectrometry, Method
524." Environmental Monitoring and Support Laboratory, U.S.
Environmental Protection Agency, Cincinnati, Ohio, February 1983.
2. Glaser, J.A., O.L. Foerst, 6.0. McKee, S.A. Quave, and W.L. 8udde,
"Trace Analyses for Wastewaters," Environ. Sc1. Techno!., 15, 1426, 1981.
3. "Carcinogens-Working with Carcinogens," Department of Health, Education,
and Welfare, Public Health Service, Center for Disease Control, National
Institute for Occupational Safety and Health, Publication No. 77-206,
August, 1977.
4. "OSHA Safety and Health Standards, General Industry," (29CFR1910),
Occupational Safety and Health Administration, OSHA 2206, (Revised,
January 1976).
5. "Safety in Academic Cheirfstry Laboratories,'* American Chemical Society
Publication, Committee on Chemical Safety, 3rd Edition, 1979.
-------
6. Bellar, T.A. and J.J. Lichtenberg, "The Determination of Synthetic
Organic Compounds in Water by Purge and Sequential Trapping Capillary
Column Gas Chromatography," U.S. Environmental Protection Agency,
Environmental Monitoring and Support Laboratory, Cincinnati, Ohio,
January 1985.
7. Budde, W.l. and Elchelberger, J.W., "Performance Tests for the
Evaluation of Computerized Gas Chromatography/Mass Spectrometry
Equipment and Laboratories," EPA-600/4-80-025, U. S. Environmental
Protection Agency, Environmental Monitoring and Support Laboratory,
Cincinnati, OH 45268.
8. Slater, R.W., 'Method Detection Limits for Drinking Water VolatHes,"
Unpublished report, June 1986.
9. Madding, C., Memorandum to H. 8rass, June 1986.
-------
OPTIONAL
FOAM R-—EXIT V* IN.
TRAP 0. D.
—14MM 0. D.
Wjy INLET 7* IN.
fcp— 0. D.
% IN.
0. 0. EOT
SAMPLE INLET
2-WAY STRINGS VALVE
17CM. 20 GAUGE SYRINGE NEEDLE
^6MM. 0. 0. RUBBER SEPTUM
-1QMM. 0. 0.
INLET
% IN. 0. 0.
1/18 IN. 0.0.
y STAINLESS STE2.
^71131 MOLECULAR
SIEVE PURGE
V6 GAS FILTER
1
101121 GLASS FRIT
MEDIUM POROSITY
M
PURGE GAS
FLOW
CONTROL
Rgura 1. Purging device
-------
PACKING PROCSURE
CONSTRUCTION
ACTIVATED
CHARCOAL 7.7032
GRADE 15 77aa
siuca Ga7,7aa
TBI AX 7.7 caa
3* OV-1 -
GLASS WOOL
7a/poor
RESISTANCE
HIRE WRAPPED
SOUD
(DOUBLE LAYER)
1SOI.
7^/FOOT.
RESISTANCE
WIRE WRAPP33
SOUD
(SINGLE LATER)
8CSH
TRAP INLET
COMPRESSION
'htting nut
AND FERRULES
THERMOCOUPLE/
CONTROLLER
S0ISOR
BJECTRONIC
TEMPERATURE!
CONTROL
AND
PYROMETER
TUBING 25CM
0.105 IN. I.D.
0.13 IN. O.D.
STAINLESS STEE.
Figure 2. Trap packings and construction to incJude
dftsorfa capability
-------
CAJOtia OAS Flow CONTROL
PRESSURE REGULATOR
PURGE GAS
FLOW CONTROL
13* MOLECUUUt
SIEVE FILTER
5-PCRT
VALVE
UOUIO INJECTION PORTS
COLUMN OVEN
^Lekwy4>-rooeT,cro"
TO OETECTOR
ANALYTICAL COLUMN
OmONAL 4-PORT COLUMN
SELECTION VALVE
TRAP INLET
/ RESISTANCE WIRE
^ 'HEATER CONTROL
—TRAP (OF?)
PURGING
OEVICE
No(a:ALL UNES SETWEBI
TRA* AND GC
SHOULD BE HEATED
TO wc
Figure 3. Purge and trap system • purge mode.
CARRIER GAS
FLOW CONTROL
UOUIO INJECTION PORTS
PRESSURE
REGULATOR.
PURGE GAS
PLOW CONTROL
UJ
13X MOLECULAR
SIEVE FILTB %
COLUMN 0VB1
CCNFIRMATORT COLUMN
« — DETECTOR
J ^-8niWl-Tr —ANALTTICAL COLUMN
N OPTIONAL 4-PORT COLUMN
saecnoN VALVE
•-PORT TRAP INLET
RESISTANCE WIRE
/
VALVE
HEATS
CONTROL
PURGING
OEVICE
Nets;
ALL UNES BETWE9I
TRAP ANO GC
SHOULD 3E HEATED
TOMaC.
Figure 4. Schematic of purge and trap device - desorb mode
-------
COLUMN: 1% SP-1QOO ON CAR80PACX-8
PROGRAM 45°C FOR 3 MIN. 8°C/MIN TO 220°C
DETECTOR: MASS S?SCTROMETB»
III
o
S
d5
o
4
0
IU
3 5 a -
i 2
> Q
d
c
a
^JxAi
§ •:
ui
2
s
o
3
£
s
IAJ
10 12 14 16 1S 20
RETENTION TIME. MIN.
24
Figure 5. Gas chromatogram of volatile organics.
-------
Column 2 - 30n long * 0.53mm 10 00-624 1 jj-j
mega-bore column 3
PnOQROMi 10 C FOR 5 MIN.,
THEN 6 /MIN TO 160 C
J I I I L
E
I
*
i' "r "i" • i'
RETENTION TIME, MIN.
Figure t. Qas chromilogrim of volatile organic*.
-------
HKH9
u
9
10
lX
»
u
II
o.SfM.mamiiQ
»
m
ii
JL
II
v
in...i
u
n
K
4ill
••h S(« f !?•
lire
IIMI
i i.i-«(wfr«orw4f
14 tWMOWIIIIMMRWf
it. mufMi
it •NOMoctaoMomoMMi (mi in)
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it tiimonmnmyMi
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tt. ikiiimniinc
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nr
Figure 7. CHROMATOORAM OF TEST MIXTURE
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