United States
Environmental Protection
\r ^1 M^k. Agency
Office of Water
www.epa.gov May 1991
Method 525.1, Revision 2.2:
Determination of Organic
Compounds in Drinking Water by
Liquid-Solid Extraction and
Capillary Column Gas
Chromatography/Mass
Spectrometry
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Note: This method is no longer approved for compliance monitoring
associated with the Safe Drinking Water Act, but it is approved for
Clean Water Act compliance monitoring associated with certain
pesticide active ingredients. See Table IG at 40 CFR Part 136.
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Method 525.1
Determination of Organic Compounds
in Drinking Water
by Liquid-Solid Extraction
and Capillary Column
Gas Chromatography/Mass Spectrometry
Revision 2.2—EPA EMSL-Ci
May 1991
J.W. Eichelberger, T.D. Behymer, W.L. Budde—
Method 525,
Revision 1.0, 2.0, 2.1 (1988)
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Method 525.1
Determination of Organic Compounds in Drinking Water by
Liquid-Solid Extraction and Capillary Column Gas
Chromatography/Mass Spectrometry
1. Scope and Application
1.1 This is a general purpose method that provides procedures for determination of
organic compounds in finished drinking water, raw source water, or drinking water
in any treatment stage. The method is applicable to a wide range of organic
compounds that are efficiently partitioned from the water sample onto a C18 organic
phase chemically bonded to a solid silica matrix in a cartridge or disk, and sufficiently
volatile and thermally stable for gas chromatography. Single-laboratory accuracy and
precision data have been determined at two concentrations with two instrument
systems for the following compounds:
Compound MW
Acenaphthylene 152
Alachlor 269
Aldrin 362
Anthracene 178
Atrazine 215
Benz [a] anthracene 228
Benzo [b]fluoranthene 252
Benzo [ic] fluoranthene 252
Benzo[a]pyrene 252
Benzo [g,h,i] perylene 276
Butylbenzyl phthalate 312
Chlordane Components
a-Chlordane 406
y-Chlordane 406
trans-Nonachlor 440
2-Chlorobiphenyl 188
Chrysene 228
Dibenz [a, h] anthracene 278
Di-n-butyl phthalate 278
2,3-dichlorobiphenyl 222
Diethyl phthalate 222
Bis(2-ethylhexyl) adipate 222
Bis(2-ethylhexy) phthalate 390
Dimethyl phthalate 194
Endrin 378
Fluorene 166
Heptachlor 370
Heptachlor epoxide 386
2,2'3,3',4,4',6-Heptachlorobiphenyl 392
CAS No.
208-96-8
15972-60-8
309-00-2
120-12-7
1912-24-9
56-55-3
205-99-2
207-08-9
50-32-8
191-24-2
85-68-7
5103-71-9
5103-74-2
39765-80-5
2051-60-7
218-01-9
53-70-3
84-72-2
16605-91-7
84-66-2
103-23-1
117-81-7
131-11-3
72-20-8
86-73-7
76-44-8
1024-57-3
52663-71-5
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Method 525.1
Compound
Hexachlorobenzene
MW
282
358
270
276
288
344
426
324
264
178
202
201
290
CAS No.
118-74-1
6-145-22-4
2,2',4,4/,5,6/-Hexachlorobiphenyl
Hexachlorocyclopentadiene
Indeno[l,2,3,c,d]pyrene
Lindane
Methoxychlor
2,2/,3,3',4,5/,6,6/-Octachlorobiphenyl
2,2,3',4,6-Pentachlorobiphenyl
Pentachlorophenol
Phenanthrene
Pyrene
Simazine
40186-71-8
60233-25-2
87-86-5
85-01-8
129-00-0
122-34-9
2437-79-8
8001-35-2
77-47-4
193-39-5
58-89-9
72-43-5
2,2',4,4/-Tetrachlorobipheneyl
Toxaphene mixture
2,4,5 -T r ichlor obipheny 1
256
15862-07-4
aMonoisotopic molecular weight calculated from the atomic masses of the
isotopes with the smallest masses.
A laboratory may use this method to identify and measure additional analytes after
the laboratory obtains acceptable (defined in Section 10) accuracy and precision data
for each added analyte.
1.2 Method detection limit (MDL) is defined as the statistically calculated minimum
amount that can be measured with 99% confidence that the reported value is greater
than zero.1 The MDL is compound dependent and is particularly dependent on
extraction efficiency and sample matrix. For the listed analytes, MDLs vary from
0.01-15 Hg/L. The concentration calibration range of this method is 0.1-10 Hg/L.
2. Summary of Method
2.1 Organic compound analytes, internal standards, and surrogates are extracted from a
water sample by passing 1 L of sample water through a cartridge or disk containing a
solid inorganic matrix coated with a chemically bonded C18 organic phase (liquid-solid
extraction, LSE). The organic compounds are eluted from the LSE cartridge or disk
with a small quantity of methylene chloride, and concentrated further by evaporation
of some of the solvent. The sample components are separated, identified, and
measured by injecting an aliquot of the concentrated methylene chloride extract into a
high resolution fused silica capillary column of a gas chromatography/mass
spectrometry (GC/MS) system. Compounds eluting from the GC column are
identified by comparing their measured mass spectra and retention times to reference
spectra and retention times in a data base. Reference spectra and retention times for
analytes are obtained by the measurement of calibration standards under the same
conditions used for samples. The concentration of each identified component is
measured by relating the MS response of the quantitation ion produced by that
compound to the MS response of the quantitation ion produced by a compound that
is used as an internal standard. Surrogate analytes, whose concentrations are known
in every sample, are measured with the same internal standard calibration procedure.
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Method 525.1
3. Definitions
3.1 Internal standard: A pure analyte(s) added to a solution in known amount(s) and
used to measure the relative responses of other method analytes and surrogates that
are components of the same solution. The internal standard must be an analyte that
is not a sample component.
3.2 Surrogate analyte: A pure analyte(s), which is extremely unlikely to be found in any
sample, and which is added to a sample aliquot in known amount(s) before extraction
and is measured with the same procedures used to measure other sample
components. The purpose of a surrogate analyte is to monitor method performance
with each sample.
3.3 Laboratory duplicates (LD1 and LD2): Two sample aliquots taken in the analytical
laboratory and analyzed separately with identical procedures. Analyses of LD1 and
LD2 give a measure of the precision associated with laboratory procedures, but not
with sample collection, preservation, or storage procedures.
3.4 Field duplicates (FD1 and FD2): Two separate samples collected at the same time and
place under identical circumstances and treated exactly the same throughout field and
laboratory procedures. Analyses of FD1 and FD2 give a measure of the precision
associated with sample collection, preservation, and storage, as well as with
laboratory procedures.
3.5 Laboratory reagent blank (LRB): An aliquot of reagent water that is treated exactly as
a sample including exposure to all glassware, equipment, solvents, reagents, internal
standards, and surrogates that are used with other samples. The LRB is used to
determine if method analytes or other interferences are present in the laboratory
environment, the reagents, or the apparatus.
3.6 Field reagent blank (FRB): Reagent water placed in a sample container in the
laboratory and treated as a sample in all respects, including exposure to sampling site
conditions, storage, preservation, and all analytical procedures. The purpose of the
FRB is to determine if method analytes or other interferences are present in the field
environment.
3.7 Laboratory performance check solution (LPC): A solution of method analytes,
surrogate compounds, and internal standards used to evaluate the performance of the
instrument system with respect to a defined set of method criteria.
3.8 Laboratory fortified blank (LFB): An aliquot of reagent water to which known
quantities of the method analytes are added in the laboratory. The LFB is analyzed
exactly like a sample, and its purpose is to determine whether the methodology is in
control, and whether the laboratory is capable of making accurate and precise
measurements at the required method detection limit.
3.9 Laboratory fortified sample matrix (LFM): An aliquot of an environmental sample to
which known quantities of the method analytes are added in the laboratory. The
LFM is analyzed exactly like a sample, and its purpose is to determine whether the
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Method 525.1
sample matrix contributes bias to the analytical results. The background
concentrations of the analytes in the sample matrix must be determined in a separate
aliquot and the measured values in the LFM corrected for background concentrations.
3.10 Stock standard solution: A concentrated solution containing a single certified
standard that is a method analyte, or a concentrated solution of a single analyte
prepared in the laboratory with an assayed reference compound. Stock standard
solutions are used to prepare primary dilution standards.
3.11 Primary dilution standard solution: A solution of several analytes prepared in the
laboratory from stock standard solutions and diluted as needed to prepare calibration
solutions and other needed analyte solutions.
3.12 Calibration standard (CAL): A solution prepared from the primary dilution standard
solution and stock standard solutions of the internal standards and surrogate analytes.
The CAL solutions are used to calibrate the instrument response with respect to
analyte concentration.
3.13 Quality control sample (QCS): A sample matrix containing method analytes or a
solution of method analytes in a water miscible solvent which is used to fortify
reagent water or environmental samples. The QCS is obtained from a source external
to the laboratory, and is used to check laboratory performance with externally
prepared test materials.
4. Interferences
4.1 During analysis, major contaminant sources are reagents and liquid-solid extraction
columns. Analyses of field and laboratory reagent blanks provide information about
the presence of contaminants.
4.2 Interfering contamination may occur when a sample containing low concentrations of
compounds is analyzed immediately after a sample containing relatively high
concentrations of compounds. Syringes and splitless injection port liners must be
cleaned carefully or replaced as needed. After analysis of a sample containing high
concentrations of compounds, a laboratory reagent blank should be analyzed to
ensure that accurate values are obtained for the next sample.
5. Safety
5.1 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 in this
method. Additional references to laboratory safety are cited.2-4
5.2 Some method analytes have been tentatively classified as known or suspected human
or mammalian carcinogens. Pure standard materials and stock standard solutions of
these compounds should be handled with suitable protection to skin, eyes, etc.
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Method 525.1
6. Apparatus and Equipment
6.1 All glassware must be meticulously cleaned. This may be accomplished by washing
with detergent and water, rinsing with water, distilled water, or solvents, air-drying,
and heating (where appropriate) in an oven. Volumetric glassware is never heated.
6.2 Sample containers. 1 L or 1 qt amber glass bottles fitted with a Teflon-lined screw
cap. (Bottles in which high purity solvents were received can be used as sample
containers without additional cleaning if they have been handled carefully to avoid
contamination during use and after use of original contents.)
6.3 Separatory funnels. 2 L and 100 mL with a Teflon stopcock.
6.4 Liquid chromatography column reservoirs. Pear-shaped 100 mL or 125 mL vessels
without a stopcock but with a ground glass outlet joint sized to fit the liquid-solid
extraction column. (Lab Glass, Inc. part no. ML-700-706S, with a 24/40 top outer joint
and a 14/35 bottom inner joint, or equivalent). A 14/35 outlet joint fits some
commercial cartridges.
6.5 Syringe needles. No. 18 or 20 stainless steel.
6.6 Vacuum flasks. 1 L or 2 L with solid rubber stoppers.
6.7 Volumetric flasks, various sizes.
6.8 Laboratory or aspirator vacuum system. Sufficient capacity to maintain a slight
vacuum of 13 cm (5 in.) of mercury in the vacuum flask.
6.9 Micro syringes, various sizes.
6.10 Vials. Various sizes of amber vials with Teflon-lined screw caps.
6.11 Drying column. Approximately 1.2 cm x 40 cm with 10 mL graduated collection vial.
6.12 Analytical balance. Capable of weighing 0.0001 g accurately.
6.13 Fused silica capillary gas chromatography column. Any capillary column that
provides adequate resolution, capacity, accuracy, and precision (Section 10) can be
used. A 30 m x 0.25 mm id fused silica capillary column coated with a 0.25 |im
bonded film of polyphenylmethylsilicone is recommended (J&W DB-5 or equivalent).
6.14 Gas chromatograph/mass spectrometer/data system (GC/MS/DS)
6.14.1 The GC must be capable of temperature programming and be equipped for
splitless/split or on-column capillary injection. The injection tube liner should
be quartz and about 3 mm in diameter. The injection system must not allow
the analytes to contact hot stainless steel or other metal surfaces that promote
decomposition.
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Method 525.1
6.14.2 The GC/MS interface should allow the capillary column or transfer line exit to
be placed within a few mm of the ion source. Other interfaces, for example
the open split interface, are acceptable as long as the system has adequate
sensitivity (see Section 9 for calibration requirements).
6.14.3 The mass spectrometer must be capable of electron ionization at a nominal
electron energy of 70 eV. The spectrometer must be capable of scanning from
45-450 amu with a complete scan cycle time (including scan overhead) of
1.5 sececonds or less. (Scan cycle time = Total MS data acquisition time in
seconds divided by number of scans in the chromatogram). The spectrometer
must produce a mass spectrum that meets all criteria in Table 1 when 5 ng or
less of DFTPP is introduced into the GC. An average spectrum across the
DFTPP GC peak may be used to test instrument performance.
6.14.4 An interfaced data system is required to acquire, store, reduce, and output
mass spectral data. The computer software must have the capability of
processing stored GC/MS data by recognizing a GC peak within any given
retention time window, comparing the mass spectra from the GC peak with
spectral data in a user-created data base, and generating a list of tentatively
identified compounds with their retention times and scan numbers. The
software must also allow integration of the ion abundance of any specific ion
between specified time or scan number limits, calculation of response factors as
defined in Section 9.2.6 (or construction of a second or third order regression
calibration curve), calculation of response factor statistics (mean and standard
deviation), and calculation of concentrations of analytes using either the
calibration curve or the equation in Section 12.
6.15 Millipore Standard Filter Apparatus, All Glass. This will be used if the disks are to be
used to carry out the extraction instead of the cartridges.
7. Reagents And Consumable Materials
7.1 Helium carrier gas, as contaminant free as possible.
7.2 Liquid-solid extraction (LSE) cartridges. Cartridges are inert non- leaching plastic, for
example polypropylene, or glass, and must not contain plasticizers, such as phthalate
esters or adipates, that leach into methylene chloride. The cartridges are packed with
about 1 gram of silica, or other inert inorganic support, whose surface is modified by
chemically bonded octadecyl (C18) groups. The packing must have a narrow size
distribution and must not leach organic compounds into methylene chloride. One
liter of water should pass through the cartridge in about two hours with the
assistance of a slight vacuum of about 13 cm (5 in.) of mercury. Section 10 provides
criteria for acceptable LSE cartridges which are available from several commercial
suppliers. The extraction disks contain approximately 0.5 grams of 8 |im octadecyl
bonded silica uniformly enmeshed in a matrix of inert PFTE fibrils. The size of the
disks is 47mm x 0.5mm. As with cartridges, the disks should not contain any organic
compounds, either from the PFTE or the bonded silica, which will leach into the
methylene chloride eluant. One liter of reagent water should pass through the disks
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Method 525.1
in 5-20 minutes using a vacuum of about 66 cm (26 in.) of mercury. Section 10
provides criteria for acceptable LSE disks which are available commercially.
7.3 Solvents
7.3.1 Methylene chloride, acetone, toluene and methanol. High purity pesticide
quality or equivalent.
7.3.2 Reagent water. Water in which an interferent is not observed at the method
detection limit of the compound of interest. Prepare reagent water by passing
tap water through a filter bed containing about 0.5 kg of activated carbon or
by using a water purification system. Store in clean, narrow-mouth bottles
with Teflon-lined septa and screw caps.
7.4 Hydrochloric acid. 6N.
7.5 Sodium sulfate, anhydrous. (Soxhlet extracted with methylene chloride for a
minimum of four hours)
7.6 Stock standard solutions. Individual solutions of analytes, surrogates, and internal
standards may be purchased as certified solutions or prepared from pure materials.
To prepare, add 10 mg (weighed on an analytical balance to 0.1 mg) of the pure
material to 1.9 mL of methanol or acetone in a 2 mL volumetric flask, dilute to the
mark, and transfer the solution to an amber glass vial. If the analytical standard is
available only in quantities smaller than 10 mg, reduce the volume of solvent
accordingly. Some polycyclic aromatic hydrocarbons are not soluble in methanol or
acetone, and their stock standard solutions are prepared in toluene. Methylene
chloride should be avoided as a solvent for standards because its high vapor pressure
leads to rapid evaporation and concentration changes. Methanol and acetone are not
as volatile as methylene chloride, but their solutions must also be handled with care
to avoid evaporation. Compounds 10, 11, and 35 in Table 2 are soluble in acetone.
Compounds 12, 13, and 20 in Table 2 are soluble in toluene. If compound purity is
certified by the supplier at >96%, the weighed amount can be used without correction
to calculate the concentration of the solution (5 |ig/|_iL). Store the amber vials in a
dark cool place.
7.7 Primary dilution standard solution. The stock standard solutions are used to prepare
a primary dilution standard solution that contains multiple analytes. The
recommended solvent for this dilution is acetone. Aliquots of each of the stock
standard solutions are combined to produce the primary dilution in which the
concentration of the analytes is at least equal to the concentration of the most
concentrated calibration solution, that is, 10 ng/|iL. Store the primary dilution
standard solution in an amber vial in a dark cool place, and check frequently for signs
of deterioration or evaporation, especially just before preparing calibration solutions.
7.8 Fortification solution of internal standards and surrogates. Prepare a solution of
acenaphthene-D10, phenanthrene-D10, chrysene-D12, and perylene-E)2 in methanol or
acetone at a concentration of 500 \ig/mL of each. This solution is used in the
preparation of the calibration solutions. Dilute a portion of this solution by
10-50 |ig/mL and use this solution to fortify the actual water samples (see
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Method 525.1
Section 11.2). Other surrogates, for example, caffeine-15N2 and pyrene-D10 may be
included in this solution as needed (a 100 |iL aliquot of this 50 |ig/mL solution added
to 1 liter of water gives a concentration of 5 Hg/L of each internal standard or
surrogate). Store this solution in an amber vial in a dark cool place.
7.9 MS performance check solution. Prepare a 5 ng/|iL solution of DFTPP in methylene
chloride. Store this solution in an amber vial in a dark cool place.
7.10 Calibration solutions (CAL1 through CAL6). Prepare a series of six concentration
calibration solutions in acetone which contain all analytes except pentachlorophenol
and toxaphene at concentrations of 10 ng/|iL, 5 ng/|iL, 2 ng/|iL, 1 ng/|iL, 0.5 ng/|iL,
and 0.1 ng/|iL, with a constant concentration of 5 ng/|iL of each internal standard
and surrogate in each CAL solution. CAL1 through CAL6 are prepared by combining
appropriate aliquots of the primary dilution standard solution (Section 7.7) and the
fortification solution (500 |ig/mL) of internal standards and surrogates (Section 7.8).
Pentachlorophenol is included in this solution at a concentration four times the other
analytes. Toxaphene CAL solutions should be prepared as separate solutions at
concentrations of 250 ng/|iL, 200 ng/|iL, 100 ng/|iL, 50 ng/|iL, 25 ng/|iL, and
10 ng/|iL. Store these solutions in amber vials in a dark cool place. Check these
solutions regularly for signs of deterioration, for example, the appearance of
anthraquinone from the oxidation of anthracene.
7.11 Reducing agents. Sodium sulfite or sodium arsenite. Sodium thiosulfate is not
recommended as it may produce a residue of elemental sulfur that can interfere with
some analytes.
7.12 Fortification solution for optional recovery standard. Prepare a solution of
terphenyl-D14 in methylene chloride at a concentration of 500 \ig/mL. An aliquot of
this solution may be added (optional) to the extract of the LSE cartridge to check on
the recovery of the internal standards in the extraction process.
8. Sample Collection, Preservation, and Handling
8.1 Sample collection. When sampling from a water tap, open the tap and allow the
system to flush until the water temperature has stabilized (usually about two to
five minutes). Adjust the flow to about 500 mL/min and collect samples from the
flowing stream. Keep samples sealed from collection time until analysis. When
sampling from an open body of water, fill the sample container with water from a
representative area. Sampling equipment, including automatic samplers, must be free
of plastic tubing, gaskets, and other parts that may leach analytes into water.
Automatic samplers that composite samples over time must use refrigerated glass
sample containers.
8.2 Sample dechlorination and preservation. All samples should be iced or refrigerated at
4°C from the time of collection until extraction. Residual chlorine should be reduced
at the sampling site by addition of a reducing agent. Add 40-50 mg of sodium sulfite
or sodium arsenite (these may be added as solids with stirring until dissolved) to each
liter of water. Hydrochloric acid should be used at the sampling site to retard the
microbiological degradation of some analytes in unchlorinated water. The sample pH
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Method 525.1
is adjusted to <2 with 6 N hydrochloric acid. This is the same pH used in the
extraction, and is required to support the recovery of pentachlorophenol.
8.3 Holding time. Samples must be extracted within seven days and the extracts
analyzed within 30 days of sample collection.
8.4 Field blanks
8.4.1 Processing of a field reagent blank (FRB) is recommended along with each
sample set, which is composed of the samples collected from the same general
sample site at approximately the same time. At the laboratory, fill a sample
container with reagent water, seal, and ship to the sampling site along with the
empty sample containers. Return the FRB to the laboratory with filled sample
bottles.
8.4.2 When hydrochloric acid is added to samples, use the same procedures to add
the same amount to the FRB.
9. Calibration
9.1 Demonstration and documentation of acceptable initial calibration is required before
any samples are analyzed and is required intermittently throughout sample analysis
as dictated by results of continuing calibration checks. After initial calibration is
successful, a continuing calibration check is required at the beginning of each
eight-hour period during which analyses are performed. Additional periodic
calibration checks are good laboratory practice.
9.2 Initial Calibration
9.2.1 Calibrate the mass and abundance scales of the MS with calibration
compounds and procedures prescribed by the manufacturer with any
modifications necessary to meet the requirements in Section 9.2.2.
9.2.2 Inject into the GC a 1 |iL aliquot of the 5 ng/|iL DFTPP solution and acquire a
mass spectrum that includes data for m/z 45-450. Use GC conditions that
produce a narrow (at least five scans per peak) symmetrical peak. If the
spectrum does not meet all criteria (Table 1), the MS must be retuned and
adjusted to meet all criteria before proceeding with calibration. An average
spectrum across the GC peak may be used to evaluate the performance of the
system.
9.2.3 Inject a 1 |iL aliquot of a medium concentration calibration solution, for
example 0.5-2 Hg/L, and acquire and store data from m/z 45-450 with a total
cycle time (including scan overhead time) of 1.5 seconds or less. Cycle time
should be adjusted to measure at least five or more spectra during the elution
of each GC peak.
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Method 525.1
9.2.3.1 Multi-ramp temperature program GC conditions. Adjust the helium
carrier gas flow rate to about 33 cm/sec. Inject at 45°C and hold in
splitless mode for one minute. Heat rapidly to 130°C. At
three minutes, start the temperature program: 130-180°C at 12°/min;
180-240°C at 7°/min; 240-320°C at 12°/min. Start data acquisition at
five minutes.
9.2.3.2 Single ramp linear temperature program. Adjust the helium carrier gas
flow rate to about 33 cm/sec. Inject at 40°C and hold in splitless mode
for one minute. Heat rapidly to 160°C. At three minutes, start the
temperature program: 160-320°C at 6°/min; hold at 320° for
two minutes. Start data acquisition at three minutes.
9.2.4 Performance criteria for the medium calibration. Examine the stored GC/MS
data with the data system software. Figure 1 shows an acceptable total ion
chromatogram.
9.2.4.1 GC performance. Anthracene and phenanthrene should be separated
by baseline. Benz[a] anthracene and chrysene should be separated by a
valley whose height is less than 25% of the average peak height of
these two compounds. If the valley between benz [a] anthracene and
chrysene exceeds 25%, the GC column requires maintenance. See
Section 9.3.6.
9.2.4.2 MS sensitivity. The GC/MS/DS peak identification software should be
able to recognize a GC peak in the appropriate retention time window
for each of the compounds in calibration solution, and make correct
tentative identifications. If fewer than 99% of the compounds are
recognized, system maintenance is required. See Section 9.3.6.
9.2.4.3 Lack of degradation of endrin. Examine a plot of the abundance of
m/z 67 in the region of 1.05-1.3 of the retention time of endrin. This is
the region of elution of endrin aldehyde, a product of the thermal
isomerization of endrin. Confirm that the abundance of m/z 67 at the
retention time of endrin aldehyde is <10% of the abundance of m/z 67
produced by endrin. If more than 10% endrin aldehyde is observed,
system maintenance is required to correct the problem. See
Section 9.3.6.
9.2.5 If all performance criteria are met, inject a 1 |iL aliquot of each of the other
CAL solutions using the same GC/MS conditions.
9.2.6 Calculate a response factor (RF) for each analyte and surrogate for each CAL
solution using the internal standard whose retention time is nearest the
retention time of the analyte or surrogate. Table 2 contains suggested internal
standards for each analyte and surrogate, and quantitation ions for all
compounds. This calculation is supported in acceptable GC/MS data system
software (Section 6.14.4), and many other software programs. RF is a unitless
number, but units used to express quantities of analyte and internal standard
must be equivalent.
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Method 525.1
Equation 1
(A ) (Q,J
RF ="(Als) (OJ
where:
A = intergrated abundance of the quantitation ion of the analyte.
Ais = integrated abundance of the quantitation ion internal standard.
Q = quantity of analyte injected in ng or concentration units.
Qis = quantity of internal injected in ng or concentration units.
9.2.6.1 For each analyte and surrogate, calculate the mean RF from the
analyses of the six CAL solutions. Calculate the standard deviation
(SD) and the relative standard deviation (RSD) from each mean: RSD =
100 (SD/M). If the RSD of any analyte or surrogate mean RF exceeds
30%, either analyze additional aliquots of appropriate CAL solutions to
obtain an acceptable RSD of RFs over the entire concentration range, or
take action to improve GC/MS performance. See Section 9.2.7.
9.2.7 As an alternative to calculating mean response factors and applying the RSD
test, use the GC/MS data system software or other available software to
generate a linear, second, or third order regression calibration curve.
9.3 Continuing calibration check. Verify the MS tune and initial calibration at the
beginning of each eight hour work shift during which analyses are performed using
the following procedure.
9.3.1 Inject a 1 |iL aliquot of the 5 ng/|iL DFTPP solution and acquire a mass
spectrum that includes data for m/z 45-450. If the spectrum does not meet all
criteria (Table 1), the MS must be retuned and adjusted to meet all criteria
before proceeding with the continuing calibration check.
9.3.2 Inject a 1 |iL aliquot of a medium concentration calibration solution and
analyze with the same conditions used during the initial calibration.
9.3.3 Demonstrate acceptable performance for the criteria shown in Section 9.2.4.
9.3.4 Determine that the absolute areas of the quantitation ions of the internal
standards and surrogate (s) have not decreased by more than 30% from the
areas measured in the most recent continuing calibration check, or by more
than 50% from the areas measured during initial calibration. If these areas
have decreased by more than these amounts, adjustments must be made to
restore system sensitivity. These adjustments may require cleaning of the MS
ion source, or other maintenance as indicated in Section 9.3.6, and
recalibration. Control charts are useful aids in documenting system sensitivity
changes.
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Method 525.1
9.3.5 Calculate the RF for each analyte and surrogate from the data measured in the
continuing calibration check. The RF for each analyte and surrogate must be
within 30% of the mean value measured in the initial calibration.
Alternatively, if a second or third order regression is used, the point from the
continuing calibration check for each analyte and surrogate must fall, within
the analyst's judgement, on the curve from the initial calibration. If these
conditions do not exist, remedial action must be taken which may require
reinitial calibration.
9.3.6 Some possible remedial actions. Major maintenance such as cleaning an ion
source, cleaning quadrupole rods, etc. require returning to the initial
calibration step.
9.3.6.1 Check and adjust GC and/or MS operating conditions; check the MS
resolution, and calibrate the mass scale.
9.3.6.2 Clean or replace the splitless injection liner; silanize a new injection
liner.
9.3.6.3 Flush the GC column with solvent according to manufacturer's
instructions.
9.3.6.4 Break off a short portion (about 1 meter) of the column from the end
near the injector; or replace GC column. This action will cause a
change in retention times.
9.3.6.5 Prepare fresh CAL solutions, and repeat the initial calibration step.
9.3.6.6 Clean the MS ion source and rods (if a quadrupole).
9.3.6.7 Replace any components that allow analytes to come into contact with
hot metal surfaces.
9.3.6.8 Replace the MS electron multiplier, or any other faulty components.
10. Quality Control
10.1 Quality control (QC) requirements are the initial demonstration of laboratory
capability followed by regular analyses of laboratory reagent blanks, laboratory
fortified blanks, and laboratory fortified matrix samples. The laboratory must
maintain records to document the quality of the data generated. Additional quality
control practices are recommended.
10.2 Initial demonstration of low system background and acceptable particle size and
packing. Before any samples are analyzed, or any time a new supply of cartridges or
disks is received from a supplier, it must be demonstrated that a laboratory reagent
blank (LRB) is reasonably free of contamination that would prevent the determination
of any analyte of concern. In this same experiment, it must be demonstrated that the
-------
Method 525.1
particle size and packing of the LSE cartridge or disk are acceptable. Consistent flow
rate is an indication of acceptable particle size distribution and packing.
10.2.1 A major source of potential contamination is the liquid-solid extraction (LSE)
cartridge which could contain phthalate esters, silicon compounds, and other
contaminants that could prevent the determination of method analytes.5
Although disks are made of a teflon matrix, they may still contain phthalate
materials. Generally, phthalate esters will be leached from the cartridges into
methylene chloride and produce a variable background that is equivalent to
<2 Hg/L in the water sample. If the background contamination is sufficient to
prevent accurate and precise analyses, the condition must be corrected before
proceeding with the initial demonstration. Figure 2 shows unacceptable
background contamination from a poor quality commercial LSE cartridge. The
background contamination is the large broad peak, and the small peaks are
method analytes present at a concentration equivalent to 2 Hg/L. Several
sources of LSE cartridges may be evaluated before an acceptable supply is
identified.
10.2.2 Other sources of background contamination are solvents, reagents, and
glassware. Background contamination must be reduced to an acceptable level
before proceeding with the next section. In general, background from method
analytes should be below the method detection limit.
10.2.3 One liter of water should pass through a cartridge in about two hours with a
partial vacuum of about 13 cm (5 in.) of mercury. The flow rate through a
disk should be about 5-20 minutes for a liter of drinking water, using full
aspirator or pump vacuum. The extraction time should not vary unreasonably
among a set of LSE cartridges or disks.
10.3 Initial demonstration of laboratory accuracy and precision. Analyze four to seven
replicates of a laboratory fortified blank containing each analyte of concern at a
concentration in the range of 2-5 Hg/L (see regulations and maximum contaminant
levels for guidance on appropriate concentrations).
10.3.1 Prepare each replicate by adding an appropriate aliquot of the primary
dilution standard solution, or another certified quality control sample, to
reagent water. Analyze each replicate according to the procedures described
in Section 11 and on a schedule that results in the analyses of all replicates
over a period of several days.
10.3.2 Calculate the measured concentration of each analyte in each replicate, the
mean concentration of each analyte in all replicates, and mean accuracy (as
mean percentage of true value) for each analyte, and the precision (as relative
standard deviation, RSD) of the measurements for each analyte. Calculate the
MDL of each analyte using the procedures described in Section 13.1.2.1
10.3.3 For each analyte and surrogate, the mean accuracy, expressed as a percentage
of the true value, should be 70-130% and the RSD should be <30%. Some
analytes, particularly the polycyclic aromatic hydrocarbons with molecular
weights >250, are measured at concentrations below 2 Hg/L, with a mean
-------
Method 525.1
accuracy of 35-130% of true value. The MDLs should be sufficient to detect
analytes at the regulatory levels. If these criteria are not met for an analyte,
take remedial action and repeat the measurements for that analyte to
demonstrate acceptable performance before samples are analyzed.
10.3.4 Develop and maintain a system of control charts to plot the precision and
accuracy of analyte and surrogate measurements as a function of time.
Charting of surrogate recoveries is an especially valuable activity since these
are present in every sample and the analytical results will form a significant
record of data quality.
10.4 Monitor the integrated areas of the quantitation ions of the internal standards and
surrogates in continuing calibration checks (see Section 9.3.4). In laboratory fortified
blanks or samples, the integrated areas of internal standards and surrogates will not
be constant because the volume of the extract will vary (and is difficult to keep
constant). But the ratios of the areas should be reasonably constant in laboratory
fortified blanks and samples. The addition of 10 |iL of the recovery standard,
terphenyl-D14 (500 |ig/mL), to the extract is optional, and may be used to monitor the
recovery of internal standards and surrogates in laboratory fortified blanks and
samples. Internal standard recovery should be in excess of 70%.
10.5 Laboratory reagent blanks. With each batch of samples processed as a group within a
work shift, analyze a laboratory reagent blank to determine the background system
contamination. Any time a new batch of LSE cartridges or disks is received, or new
supplies of other reagents are used, repeat the demonstration of low background
described in Section 10.2.
10.6 With each batch of samples processed as a group within a work shift, analyze a single
laboratory fortified blank (LFB) containing each analyte of concern at a concentration
as determined in Section 10.3. If more than 20 samples are included in a batch,
analyze a LFB for every 20 samples. Use the procedures described in Section 10.3.3 to
evaluate the accuracy of the measurements, and to estimate whether the method
detection limits can be obtained. If acceptable accuracy and method detection limits
cannot be achieved, the problem must be located and corrected before further samples
are analyzed. Add these results to the on-going control charts to document data
quality.
10.7 Determine that the sample matrix does not contain materials that adversely affect
method performance. This is accomplished by analyzing replicates of laboratory
fortified matrix samples and ascertaining that the precision, accuracy, and method
detection limits of analytes are in the same range as obtained with laboratory fortified
blanks. If a variety of different sample matrices are analyzed regularly, for example,
drinking water from groundwater and surface water sources, matrix independence
should be established for each. A laboratory fortified sample matrix should be
analyzed for every 20 samples processed in the same batch.
10.8 With each set of field samples a field reagent blank (FRB) should be analyzed. The
results of these analyses will help define contamination resulting from field sampling
and transportation activities.
-------
Method 525.1
10.9 At least quarterly, replicates of laboratory fortified blanks should be analyzed to
determine the precision of the laboratory measurements. Add these results to the
on-going control charts to document data quality (as in Section 10.3).
10.10 At least quarterly, analyze a quality control sample from an external source. If
measured analyte concentrations are not of acceptable accuracy (Section 10.3.3), check
the entire analytical procedure to locate and correct the problem source.
10.11 Numerous other quality control measures are incorporated into other parts of this
procedure, and serve to alert the analyst to potential problems.
11. Procedure
11.1 Cartridge Extraction
11.1.1 Setup the extraction apparatus shown in Figure 3A. The reservoir is not
required, but recommended for convenient operation. Water drains from the
reservoir through the LSE cartridge and into a syringe needle which is inserted
through a rubber stopper into the suction flask. A slight vacuum of 13 cm
(5 in.) of mercury is used during all operations with the apparatus. The
pressure used is critical as a vacuum greater than 13 cm may result in poor
precision. About two hoursis required to draw a liter of water through the
system.
11.1.2 Pour the water sample into the 2 L separatory funnel with the stopcock closed,
add 5 mL methanol, and mix well. Residual chlorine should not be present as
a reducing agent should have been added at the time of sampling. Also the
pH of the sample should be about 2. If residual chlorine is present and/or the
pH is >2, the sample may be invalid. Add a 100 |iL aliquot of the fortification
solution (50 \ig/mL) for internal standards and surrogates, and mix
immediately until homogeneous. The concentration of these compounds in the
water should be 5 Hg/L.
11.1.3 Flush each cartridge with two 10 mL aliquots of methylene chloride, followed
by two 10 mL aliquots of methanol, letting the cartridge drain dry after each
flush. These solvent flushes may be accomplished by adding the solvents
directly to the solvent reservoir in Figure 3A. Add 10 mL of reagent water to
the solvent reservoir, but before the reagent water level drops below the top
edge of the packing in the LSE cartridge, open the stopcock of the separatory
funnel and begin adding sample water to the solvent reservoir. Close the
stopcock when an adequate amount of sample is in the reservoir.
11.1.4 Periodically open the stopcock and drain a portion of the sample water into
the solvent reservoir. The water sample will drain into the cartridge, and from
the exit into the suction flask. Maintain the packing material in the cartridge
immersed in water at all times. After all of the sample has passed through the
LSE cartridge, wash the separatory funnel and cartridge with 10 mL of reagent
water, and draw air through the cartridge for 10 minutes.
-------
Method 525.1
11.1.5 Transfer the 125 mL solvent reservoir and LSE cartridge (from Figure 3A) to
the elution apparatus (Figure 3B). The same 125 mL solvent reservoir is used
for both apparatus. Wash the 2 L separatory funnel with 5 mL of methylene
chloride and collect the washings. Close the stopcock on the 100 mL
separatory funnel of the elution apparatus, add the washings to the reservoir
and enough additional methylene chloride to bring the volume back up to
5 mL and elute the LSE cartridge. Elute the LSE cartridge with an additional
5 mL of methylene chloride (10 mL total). A small amount of nitrogen
positive pressure may be used to elute the cartridge. Small amounts of
residual water from the LSE cartridge will form an immiscible layer with the
methylene chloride in the 100 mL separatory funnel. Open the stopcock and
allow the methylene chloride to pass through the drying column packed with
anhydrous sodium sulfate (1 in) and into the collection vial. Do not allow the
water layer to enter the drying column. Remove the 100 mL separatory funnel
and wash the drying column with 2 mL of methylene chloride. Add this to
the extract. Concentrate the extract to 1 mL under a gentle stream of nitrogen.
If desired, gently warm the extract in a water bath to evaporate to between
0.5-1.0 mL (without gas flow). Do not concentrate the extract to less than
0.5 mL (or dryness) as this will result in losses of analytes. If desired, add an
aliquot of the recovery standard to the concentrated extract to check the
recovery of the internal standards (see Section 10.4).
11.2 Disk Extraction (This may be manual or automatic)
11.2.1 Preparation of Disks
11.2.1.1 Insert the disk into the 47 mm filter apparatus as shown in
Figure 4. Wash the disk with 5mL methylene chloride (MeC12)
by adding the MeC12 to the disk, drawing about half through
the disk, allowing it to soak the disk for about a minute, then
drawing the remaining MeC12 through the disk.
11.2.1.2 Pre-wet the disk with 5 mL methanol (MeOH) by adding the
MeOH to the disk and allowing it to soak for about a minute,
then drawing most of the remaining MeOH through. A layer of
MeOH must be left on the surface of the disk, which should not
be allowed to go dry from this point until the end of the sample
extraction. THIS IS A CRITICAL STEP FOR A UNIFORM
FLOW AND GOOD RECOVERY.
11.2.1.3 Rinse the disk with 5 mL reagent water by adding the water to
the disk and drawing most through, again leaving a layer on the
surface of the disk.
11.2.2 Add 5 mL MeOH per liter of water sample. Mix well.
11.2.3 Add the water sample to the reservoir and turn on the vacuum to begin the
extraction. Full aspirator vacuum may be used. Particulate-free water may
pass through the disk in as little as ten minutes or less. Extract the entire
sample, draining as much water from the sample container as possible.
-------
Method 525.1
11.2.4 Remove the filtration top from the vacuum flask, but do not disassemble the
reservoir and fritted base. Empty the water from the flask, and insert a
suitable sample tube to contain the eluant. The only constraint on the sample
tube is that it fit around the drip tip of the fritted base. Reassemble the
apparatus.
11.2.5 Add 5 mL methylene chloride to the sample bottle, and rinse the inside walls
thoroughly. Allow the methylene chloride to settle to the bottom of the bottle,
and transfer to the disk with a pipet or syringe, rinsing the sides of the glass
filtration reservoir in the process. Draw about half of the methylene chloride
through the disk, release the vacuum, and allow the disk to soak for a minute.
Draw the remaining methylene chloride through the disk.
11.2.6 Repeat the above step twice. Pour the combined eluates through a small
funnel with filter paper containing three grams of anhydrous sulfate. Rinse
the test tube and sodium sulfate with two 5 mL portions of methylene
chloride. Collect all the extract and washings in a concentrator tube.
11.2.7 Concentrate the extract to 1 mL under a gentle stream of nitrogen. If desired,
gently warm the extract in a water bath or heating block to concentrate to
between 0.5 mL and 1 mL. Do not concentrate the extract to less than 0.5 mL,
since this will result in losses of analytes.
11.3 Analyze a 1-2 |iL aliquot with the GC/MS system under the same conditions used for
the initial and continuing calibrations (Section 9.2.3).
11.4 At the conclusion of data acquisition, use the same software that was used in the
calibration procedure to tentatively identify peaks in retention time windows of
interest. Use the data system software to examine the ion abundances of components
of the chromatogram. If any ion abundance exceeds the system working range, dilute
the sample aliquot and analyze the diluted aliquot.
11.5 Identification of analytes. Identify a sample component by comparison of its mass
spectrum (after background subtraction) to a reference spectrum in the user-created
data base. The GC retention time of the sample component should be within
10 seconds of the time observed for that same compound when a calibration solution
was analyzed.
11.5.1 In general, all ions that are present above 10% relative abundance in the mass
spectrum of the standard should be present in the mass spectrum of the
sample component and should agree within absolute 20%. For example, if an
ion has a relative abundance of 30% in the standard spectrum, its abundance
in the sample spectrum should be in the range of 10-50%. Some ions,
particularly the molecular ion, are of special importance, and should be
evaluated even if they are below 10% relative abundance.
11.5.2 Identification is hampered when sample components are not resolved
chromatographically and produce mass spectra containing ions contributed by
more than one analyte. When GC peaks obviously represent more than one
sample component (i.e., broadened peak with shoulder(s) or valley between
-------
Method 525.1
two or more maxima), appropriate analyte spectra and background spectra can
be selected by examining plots of characteristic ions for tentatively identified
components. When analytes coelute (i.e., only one GC peak is apparent), the
identification criteria can be met but each analyte spectrum will contain
extraneous ions contributed by the coeluting compound.
11.5.3 Structural isomers that produce very similar mass spectra can be explicitly
identified only if they have sufficiently different GC retention times. See
Section 9.2.4.1. Acceptable resolution is achieved if the height of the valley
between two isomer peaks is less than 25% of the average height of the two
peak heights. Otherwise, structural isomers are identified as isomeric pairs.
Benzo[b] and benzo [k] fluoranthene are measured as an isomeric pair.
11.5.4 Phthalate esters and other background components appear in variable
quantities in laboratory and field reagent blanks, and generally cannot be
accurately measured at levels below about 2 Hg/L. Subtraction of the
concentration in the blank from the concentration in the sample at or below
the 2 Hg/L level is not recommended because the concentration of the
background in the blank is highly variable.
12. Calculations
12.1 Complete chromatographic resolution is not necessary for accurate and precise
measurements of analyte concentrations if unique ions with adequate intensities are
available for quantitation. For example, although two listed analytes,
dibenz[a,h]anthracene and indeno[l,2,3,c,d]pyrene, were not resolved with the GC
conditions used, and produced mass spectra containing common ions, concentrations
(Tables 3-6) were calculated by measuring appropriate characteristic ions.
12.1.1 Calculate analyte and surrogate concentrations.
Equation 2
c _ (A) m
x (A,) & v
where:
Cx = concentration of analyte or surrogate in \ig/L in the water sample.
Ax = integrated abundance of the quantitation ion of the analyte in the sample.
Ajs = integrated abundance of the quantitation ion of the analyte in the sample.
Qis = total quantity (in micrograms) of internal standard added to the water sample.
V = original water sample volume in liters.
RF = mean response factor of analyte from the initial calibration.
12.1.2 Alternatively, use the GC/MS system software or other available proven
software to compute the concentrations of the analytes and surrogates from the
second or third order regression curves.
-------
Method 525.1
12.1.3 Calculations should utilize all available digits of precision, but final reported
concentrations should be rounded to an appropriate number of significant
figures (one digit of uncertainity). Experience indicates that three significant
figures may be used for concentrations above 99 Hg/L, two significant figures
for concentrations between 1-99 Hg/L, and one significant figure for lower
concentrations.
13. Method Performance
13.1 Single laboratory accuracy and precision data (Tables 3-7) for each listed analyte was
obtained at two concentrations with the same extracts analyzed on more than two
different instrument systems. Seven 1 L aliquots of reagent water containing 2 Hg/L
of each analyte, and five to seven 1 L aliquots of reagent water containing 0.2 Hg/L of
each analyte were analyzed with this procedure. Tables 8-10 list data gathered using
C-18 disks. These data were results from different extracts generated by a volunteer
laboratory, Environmental Health Laboratories.
With these data, method detection limits (MDL) were calculated using the formula:
MDL = S t, , , . Q..
(n-l, 1-a = 0. 99)
where:
t, i . ... = student's t value for the 99% confidence level with n-1 degrees of freedom
(n-l,1-a = 0.99) =
n = number of replicates
S = standard deviation of replicate analyses
13.2 Problem Compounds
13.2.1 The common phthalate and adipate esters (Compounds 14, 21, and 23-26),
which are widely used commercially, appear in variable quantities in
laboratory and field reagent blanks, and generally cannot be accurately or
precisely measured at levels below about 2 Hg/L. Subtraction of the
concentration in the blank from the concentration in the sample at or below
the 2 Hg/L level is not recommended because the concentrations of the
background in blanks is highly variable.
13.2.2 Some polycyclic aromatic hydrocarbons are rapidly oxidized and/or
chlorinated in water containing residual chlorine. Therefore residual chlorine
must be reduced before analysis.
13.2.3 In water free of residual chlorine, some polycyclic aromatic hydrocarbons (for
example, Compounds 9, 12, 13, 20, and 35) are not accurately measured
because of low recoveries in the extraction process.
13.2.4 Pentachlorophenol No. 40 and hexachlorocyclopentadiene No. 34 may not be
accurately measured. Pentachlorophenol is a strong acid and elutes as a broad
-------
Method 525.1
weak peak. Hexachlorocyclopentadiene is susceptible to photochemical and
thermal decomposition.
References
1. Glaser, J.A., Foerst, D.L., McKee, G.D., Quave, S.A., and Budde, W.L. "Trace
Analyses for Wastewaters," Environ. Sci. Technol. 1981 Jj3, 1426-1435.
2. "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.
3. "OSHA Safety and Health Standards, General Industry," (29CFi?1910), Occupational
Safety and Health Administration, OSHA 2206, (Revised, January 1976).
4. "Safety in Academic Chemistry Laboratories," American Chemical Society Publication,
Committee on Chemical Safety, 3rd Edition, 1979.
5. Junk, G.A., Avery, M.J., and Richard, J.J. "Interferences in Solid-Phase Extraction
Using C-18 Bonded Porous Silica Cartridges," Anal. Chem. 1988, 60, 1347.
-------
Method 525.1
Table 1. Ion Abundance Criteria for Bis (perfluorophenyl) phenyl Phosphine
(Decafluorotriphenylphosphine, DFTPP)
Mass
(M/z)
Relative Abundance Criteria
Purpose of Checkpoint1
51
10-80% of the base peak
Low mass sensitivity
68
<2% of mass 69
Low mass resolution
70
<2% of mass 69
Low mass resolution
127
10-80% of the base peak
Low-mid mass sensitivity
197
<2% of mass 198
Mid-mass resolution
198
base peak or >50% of 442
Mid-mass resolution and sensitivity
199
5-9% of mass 198
Mid-mass resolution and isotope ratio
275
10-60% of the base peak
Mid-high mass sensitivity
365
>1% of the base peak
Baseline threshold
441
Present and < mass 443
High mass resolution
442
base peak or >50% of 198
High mass resolution and sensitivity
443
15-24% of mass 442
High mass resolution and isotope ratio
'All ions are used primarily to check the mass measuring accuracy of the mass spectrometer
and data system, and this is the most important part of the performance test. The three
resolution checks, which include natural abundance isotope ratios, constitute the next most
important part of the performance test. The correct setting of the baseline threshold, as
indicated by the presence of low intensity ions, is the next most important part of the
performance test. Finally, the ion abundance ranges are designed to encourage some
standardization to fragmentation patterns.
-------
Method 525.1
Table 2. Retention Time Data, Quantitation Ions, and Internal Standard References for
Method Analytes
Retention
Time (min:sec)
Compound
Compound
Number
Bb
Internal
Quantitation Standard
Ion (m/z) Reference
Internal standard
Acenapththene-D10
1
4:49
7:45
164
-
Phenanthrene-D10
2
8:26
11:08
188
-
Chrysene-D12
3
18:14
19:20
240
-
Surrogate
Perylene-D12
4
23:37
22:55
264
3
Target analytes
Acenphthylene
5
4:37
7:25
152
1
Aldrin
6
11:21
13:36
66
2
Anthracene
7
8:44
11:20
178
2
Atrazine
8
7:56
10:42
200/215
1/2
Benz [a] anthracene
9
18:06
19:14
228
3
Benzo [b] fluoranthene
10
22:23
22:07
252
3
Benzo [ic] fluoranthene
11
22:28
22:07
252
3
Benzo[a]pyrene
12
23:28
22:47
252
3
Benzo [g,h,i] perylene
13
27:56
26:44
276
3
Buthylbenzyl phthalate
14
16:40
18:09
149
2/3
Chlordane Components
a-Chlordane
15
13:44
15:42
375
2/3
y-Chlordane
16
13:16
15:18
375
2/3
trans-Nonachlor
17
13:54
15:50
409
2/3
2-Chlorobiphenyl
18
4:56
7:55
188
1
Chrysene
19
18:24
19:23
228
3
Dibenz [a,h] anthracene
20
27:15
25:57
278
3
Di-n-butyl phthalate 2,3-
21
10:58
13:20
149
2
Dichlorobiphenyl
22
7:20
10:12
222
1
Diethyl phthalate
23
5:52
8:50
149
1
Di(2-ethylhexyl)
phthalate
24
19:19
20:01
149
2/3
Di(2-ethylhexyl) adipate
25
17:17
18:33
129
2/3
Dimethyl phthalate
26
4:26
7:21
163
1
Endrin
27
15:52
16:53
81
2/3
Fluorene
28
6:00
8:53
166
1
Heptaclor
29
10:20
12:45
100/160
2
Heptachlor epoxide
30
12:33
14:40
81/353
2
2,2',3,3',4,4',6-Hepta-
chlorobiphenyl
31
18:25
19:25
394/396
3
-------
Method 525.1
Table 2. Retention Time Data, Quantitation Ions, and Internal Standard References for
Method Analytes
Retention
Time (min:sec)
Compound
Internal
Quantitation Standard
Compound
Number
Aa
Bb
Ion (m/z)
Hexachlorobenzene
32
7:37
10:20
284/286
2,2',4,4',5,6'-Hexa-
chlorobiphenyl
33
14:34
16:30
360
Hexachloro-
cyclopentadiene
34
3:36
6:15
237
Indeno[l,2,3,c,d]pyrene
35
27:09
25:50
276
1/2
2
1
3
Table 2. Retention Time Data, Quantitation Ions, and Internal Standard References for
Method Analytes (cont.)
Retention
Internal
Compound
Time (min.sec)
Quantitation
Standard
Compound
Number
Aa
\ Bb
Ion (m/z)
Reference
Lindane
36
8:17
10:57
181/183
1/2
Methoxychlor
37
18:34
19:30
227
3
2,2',3,3',4,5',6,6'-
Octachlorobiphenyl
38
18:38
19:33
430
3
2,2',3',4,6-Penta-
chlorobiphenyl
39
12:50
15:00
326
2
Pentachlorophenol
40
8:11
10:51
266
2
Phenanthrene
41
8:35
11:13
178
2
Pyrene
42
13:30
15:29
202
2/3
Simazine
43
7:47
10:35
201
1/2
2,2',4,4'-Tetrachloro-
biphenyl
44
11:01
13:25
292
2
Toxaphene
45
11:30-23:30 13:00-21:30
159
2
2,4,5 -T r ichlor obipheny 1
46
9:23
11:59
256
2
Alachlor
47
--
13:19
160
2
aSingle ramp linear temperature program conditions (Section 9.2.3.2).
bMulti-ramp linear temperature program conditions (Section 9.2.3.1).
-------
Method 525.1
Table 3. Accuracy and Precision Data from Seven Determinations of the Method
Analytes at 2 Hg/L With Liquid-Solid Extraction and the Ion Trap Mass Spectrometer
Mean Mean Method Method
Compound
Observed
Rel. Std.
Accuracy
Detection
Number
True Cone.
Cone.
Std. Dev.
Dev.
(% of True
Limit (MDL
(Table 2)
(m/l)
(m/l)
(m/l)
(%)
Cone.)
(m/l)
4
5
5.0
0.3
6.0
100
a
5
2
1.9
0.2
11.
95
a
6
2
1.6
0.2
13.
80
a
7
2
1.7
0.1
5.9
85
a
8
2
2.2
0.3
14.
110
a
9
2
1.8
0.2
11.
90
a
10
2
not separated from No.
11; measured with No. 11
11
2
4.2
0.3
7.1
105
a
12
2
0.8
0.2
25.
40
a
13
2
0.7
0.1
14.
35
a
14
2
2.0
0.3
15.
100
a
15
2
2.0
0.2
10.
100
a
16
2
2.2
0.3
14.
110
a
17
2
2.7
1.0
37.
135
a
18
2
1.9
0.1
5.2
95
a
19
2
2.2
0.1
4.5
110
a
20
2
0.3
0.3
100.
15
a
21
2
2.2
0.3
14.
110
a
22
2
2.3
0.1
4.3
115
a
23
2
2.0
0.3
15.
100
a
24
2
1.9
0.2
11.
95
a
25
2
1.6
0.3
19.
80
a
26
2
1.9
0.2
11.
95
a
27
2
1.8
0.1
5.5
90
a
28
2
2.2
0.2
9.1
110
a
29
2
2.2
0.3
14.
110
a
30
2
2.3
0.2
8.7
115
a
31
2
1.4
0.2
14.
70
a
32
2
1.7
0.2
12.
85
a
33
2
1.6
0.4
25.
80
a
34
2
1.1
0.1
9.1
55
a
35
2
0.4
0.2
50.
20
a
36
2
2.1
0.2
9.5
105
a
37
2
1.8
0.2
11.
90
a
38
2
1.8
0.2
11.
90
a
39
2
1.9
0.1
5.3
95
a
40
8
8.2
1.2
15.
102
a
41
2
2.4
0.1
4.2
120
a
42
2
1.9
0.1
5.3
95
a
43
2
2.1
0.2
9.5
105
a
44
2
1.5
0.1
6.7
75
a
45
25
28.
4.7
17.
112
15.
46
2
1.7
0.1
5.9
85
a
Meanb
2
1.8
0.2
15.
91
0.6
aSee Table 4.
bCompounds 4, 40, and 45 excluded from the means.
-------
Method 525.1
Table 4. Accuracy and Precision Data from Five to Seven Determinations of the Method
Anaytes at 0.2 Hg/L with Liquid-Solid Extraction and the Ion Trap Mass Spectrometer
Compound Mean Rel Std. Mean Method Method
Number True Cone. Observed Std. Dev Dev. Accuracy Detection Limit
(Table 2)
(m/L)
Cone. (\i/L)
(m/l)
(%)
(% of True Cone.)
(MDL) (pig/L)
4
0.5
0.45
0.6
13.
90
0.1
5
0.2
0.13
0.03
23.
65
0.1
6
0.2
0.13
0.03
23.
65
0.1
7
0.2
0.13
0.01
7.7
65
0.04
8
0.2
0.24
0.03
13.
120
0.1
9
0.2
0.14
0.01
7.1
70
0.04
10 0.2 not separated from No. 11; measured with No. 11
11
0.2
0.25
0.04
16.
62
0.2
12
0.2
0.03
0.01
33.
15
0.04
13
0.2
0.03
0.02
67.
15
0.1
14
0.2
0.32
0.07
22.
160
0.3
15
0.2
0.17
0.04
24.
85
0.2
16
0.2
0.19
0.03
16.
95
0.1
17
0.2
0.17
0.08
47.
85
0.3
18
0.2
0.19
0.03
16.
95
0.1
19
0.2
0.21
0.01
4.8
105
0.04
20
0.2
0.03
0.02
67.
150
0.1
21
0.2
0.48
0.09
19.
240
0.3
22
0.2
0.20
0.03
15.
100
0.1
23
0.2
0.45
0.21
47.
225
0.8
24
0.2
0.39
0.16
41.
195
0.6
25
0.2
0.31
0.16
52.
155
0.6
26
0.2
0.21
0.01
4.8
105
0.04
27
0.2
0.12
0.12
100.
60
0.5
28
0.2
0.21
0.05
24.
105
0.2
29
0.2
0.22
0.01
4.5
110
0.04
30
0.2
0.19
0.04
21.
95
0.2
31
0.2
0.19
0.03
16.
95
0.1
32
0.2
0.16
0.04
25.
80
0.1
33
0.2
0.19
0.03
16.
95
0.1
34
0.2
0.04
0.01
25.
20
0.03
35
0.2
0.04
0.03
75.
20
0.1
36
0.2
0.22
0.02
9.1
110
0.1
37
0.2
0.11
0.01
9.1
55
0.04
38
0.2
0.19
0.05
26.
95
0.2
39
0.2
0.13
0.02
15.
65
0.1
40
0.2
0.78
0.08
10.
97
0.3
41
0.2
0.20
0.004
2.0
100
0.01
42
0.2
0.18
0.005
2.8
90
0.02
43
0.2
0.25
0.04
16.
125
0.02
44
0.2
0.14
0.04
29.
70
0.1
45
not measured at this level
46
0.2
0.13
0.02
15.
65
0.06
lean3
0.2
0.18
0.04
25.
95
0.16
aCompounds 4, 40, and 45 excluded from the means.
-------
Method 525.1
Table 5. Accuracy and Precision data From Five to Seven Determinations of the Method
Anaytes at 0.2 Hg/L with Liquid-Solid Extraction and a Magnetic Sector Mass Spectrometer
Compound
Mean
Rel. Std.
Mean Method
Method
Number
True Cone.
Observed
Std. Dev
Dev.
Accuracy
Detection Limit
(Table 2)
(Vg/L)
Cone. (fj/L)
(m/L)
(%)
(% of True Cone.)
|
1
4
5
5.7
0.34
6.0
114
a
5
2
1.9
0.22
12.
95
a
6
2
1.6
0.18
11.
80
a
7
2
2.2
0.67
30.
110
a
8
2
2.4
0.46
19.
120
a
9
2
2.2
0.87
40
110
a
10
2
not separated from No.
11; measured with No. 11
11
2
4.0
0.37
9.3
100
a
12
2
0.85
0.15
18.
43
a
13
2
0.69
0.12
17.
35
a
14
2
2.0
0.20
10.
100
a
15
2
2.2
0.41
19.
110
a
16
2
2.1
0.38
18.
105
a
17
2
1.9
0.10
5.2
95
a
18
2
2.0
0.29
14.
100
a
19
2
2.1
0.32
15.
105
a
20
2
0.75
0.18
24.
38
a
21
2
2.5
0.32
13.
125
a
22
2
2.0
0.23
12.
100
a
23
2
3.5
1.8
51.
175
a
24
2
2.0
0.28
14.
100
a
25
2
1.4
0.16
11.
70
a
26
2
2.9
0.70
24.
145
a
27
2
1.7
0.45
26.
85
a
28
2
2.6
1.0
38.
130
a
29
2
1.2
0.10
8.3
60
a
30
2
2.6
0.42
16.
130
a
31
2
1.5
0.19
13.
75
a
32
2
1.5
0.35
23.
75
a
33
2
1.9
0.17
8.9
95
a
34
2
0.89
0.11
12.
45
a
35
2
0.83
0.072
8.7
42
a
36
2
2.2
0.10
4.5
110
a
37
2
2.0
0.88
44.
100
a
38
2
1.5
0.11
7.3
75
a
39
2
1.6
0.14
00
00
80
a
40
8
12.
2.6
22.
150
a
41
2
2.3
0.18
7.8
115
a
42
2
2.0
0.26
13.
100
a
43
2
2.5
0.34
14.
125
a
44
2
1.6
0.17
11.
80
a
45
25
28.
2.7
10.
112
9.
46
2
1.9
0.073
3.8
95
a
Mean3
2
1.8
0.32
16.
88
1.
aSee Table 4.
bCompound 4, 40, and 45 exluded from the means.
-------
Method 525.1
Table 6. Accuracy and Precision Data from Six or Seven Determinations of the Method
Anaytes at 0.2 Hg/L with Liquid-Solid Extraction and a Magnetic Sector Spectrometer
Compound True Mean Rel. Std. Mean Method Method Detection
Number
Cone.
Observed
Std.Dev
Dev.
Accuracy
Limit (MDL)
(Table 2)
(Vg/L)
Cone. (fj/L)
(m/L)
(%)
(% of True Cone.)
(m/L)
4
0.5
0.67
0.07
9.4
134
0.2
5
0.2
0.11
0.03
24.
55
0.1
6
0.2
0.11
0.02
21.
56
0.1
7
0.2
0.14
0.02
17.
70
0.1
8
0.2
0.26
0.08
31.
130
0.3
9
0.2
0.24
0.06
26.
120
0.2
10
0.2
not separated from No.
11; measured with No. 11
11
0.2
0.40
0.10
25.
100
0.3
12
0.2
0.08
0.02
27.
38
0.1
13
0.2
0.07
0.01
22.
33
0.1
14
0.2
0.33
0.16
48.
160
0.5
15
0.2
0.19
0.02
13.
95
0.1
16
0.2
0.17
0.08
45.
85
0.3
17
0.2
0.19
0.04
18.
95
0.1
18
0.2
0.17
0.02
13.
85
0.1
19
0.2
0.27
0.08
28.
135
0.3
20
0.2
0.09
0.01
15.
46
0.1
21
0.2
1.1
1.2
109.
550
4.
22
0.2
0.18
0.05
30.
90
0.2
23
0.2
0.29
0.17
59.
145
0.6
24
0.2
0.42
0.23
55.
210
0.8
25
0.2
0.32
0.16
50.
160
0.5
26
0.2
0.20
0.09
47.
100
0.3
27
0.2
0.53
0.30
57.
265
1.
28
0.2
0.18
0.03
15.
90
0.1
29
0.2
0.11
0.05
42.
55
0.2
30
0.2
0.33
0.08
26.
165
0.3
31
0.2
0.17
0.01
7.1
85
0.04
32
0.2
0.11
0.04
40.
55
0.2
33
0.2
0.17
0.03
15.
85
0.1
34
0.2
0.05
0.02
35.
24
0.1
35
0.2
0.08
0.06
8.1
40
0.02
36
0.2
0.27
0.03
11.
135
0.1
37
0.2
0.24
0.09
39.
120
0.3
38
0.2
0.15
0.02
12.
75
0.1
39
0.2
0.13
0.02
13.
65
0.1
40
0.8
1.8
0.82
46.
225
3.
41
0.2
0.21
0.07
33.
105
0.2
42
0.2
0.19
0.04
23.
95
0.1
43
0.2
0.27
0.07
27.
135
0.2
44
0.2
0.13
0.03
22.
65
0.1
45
not measured at this point
46
0.2
0.16
0.04
23.
80
0.12
Mean3
0.2
0.21
0.09
28.
102
0.3
aCompounds 4, 40, and 45 excluded from the means.
-------
Method 525.1
Table 7. Accuracy and Precision Data from Seven Determinations at 2 Hg/L with
Liquid-Solid Extraction and a Quadrupole Mass Spectrometer
Compound True Mean Rel. Std. Mean Method Method Detection
Number Cone. Observed Std. Dev Dev. Accuracy Limit (MDL)
(Table 2) (lig/L) Cone. (fj/L) (lig/L) (%) (% of True Cone.) (pg/L)
47 2 2.4 0.4 16. 122 1.0
-------
Method 525.1
Table 8. Accuracy and Precision Data from Seven Replicates at 0.2 /j,g/L with Liquid-
solid C-18 Disk Extraction and an ion Trap Mass Spectrometer
Compound
Target
Standard
Relative
Number
Concentration
Deviation
Deviation
Mean
Accuracy
(Table 2)
(m/L)
(Vg/L)
(%)
(Vg/L)
(% of target)
1
0.2
0.01
5.3
0.22
110
4
5.0
0.37
7.4
5.55
111
6
0.2
0.03
13.2
0.26
130
7
0.2
0.03
13.7
0.22
108
8
0.2
0.04
22.4
0.21
105
9
0.2
0.07
33.2
0.29
147
10
0.2
0.16
77.6
0.40
199
11
0.2
0.03
13.7
0.21
107
12
0.2
0.04
21.7
0.26
128
13
0.2
0.03
14.9
0.23
115
14
0.2
0.07
32.5
0.37
183
15
0.2
0.12
61.1
0.19
95
16
0.2
0.06
31.9
0.19
93
17
0.2
0.18
91.3
0.55
276
18
0.2
0.01
7.2
0.16
78
19
0.2
0.02
10.9
0.27
136
20
0.2
0.05
22.9
0.18
90
21
0.2
0.08
40.3
0.47
233
22
0.2
0.02
9.7
0.17
87
23
0.2
0.02
11.9
0.27
133
24
0.2
0.50
252.0
1.54
771
25
0.2
0.04
20.8
0.36
180
26
0.2
0.02
7.6
0.23
117
27
0.2
0.05
25.4
0.23
117
28
0.2
0.01
7.3
0.20
101
29
0.2
0.05
22.9
0.28
139
30
0.2
0.08
38.9
0.36
181
31
0.2
0.08
38.0
0.28
141
32
0.2
0.04
17.7
0.22
109
33
0.2
0.06
31.9
0.19
96
34
0.2
0.01
5.2
0.34
170
35
0.2
0.05
27.0
0.29
143
36
0.2
0.01
6.5
0.22
110
37
0.2
0.03
13.4
0.20
100
38
0.2
0.04
21.1
0.20
99
39
0.2
0.03
15.1
0.17
84
40
2.0
41
0.2
0.02
12.2
0.20
102
42
0.2
0.02
10.2
0.24
121
43
0.2
0.04
18.8
0.19
94
44
0.2
0.06
28.1
0.21
107
45
20.0
2.47
12.3
24.80
123
46
0.2
0.04
21.4
0.19
95
47
0.2
0.03
14.7
0.11
55
-------
Method 525.1
Table 9. Accuracy and Precision Data from Seven Replicates at 2.0 /j,g/L with Liquid-
Solid C-18 Disk Extraction and an ion Trap Mass Spectrometer
ible 2)
(m/l)
(m/l)
(%)
(m/L)
(% of target)
1
2
0.18
9.2
2.00
100
4
5
0.45
9.1
5.22
104
6
2
0.30
14.8
2.14
107
7
2
0.17
8.6
2.25
112
8
2
0.47
23.5
2.78
139
9
2
0.21
10.4
2.21
111
10
2
0.62
30.9
2.84
142
11
2
0.57
28.7
2.30
115
12
2
0.31
15.6
2.61
130
13
2
0.28
13.9
2.28
114
14
2
0.33
16.7
2.92
146
15
2
0.62
31.1
1.21
61
16
2
1.02
51.2
1.92
96
17
2
1.39
69.3
3.29
164
18
2
0.22
11.2
2.52
126
19
2
0.23
11.6
1.99
100
20
2
0.27
13.4
2.25
113
21
2
0.23
11.3
2.45
123
22
2
0.38
18.9
2.35
117
23
2
0.22
11.1
2.23
111
24
2
0.38
19.1
3.25
163
25
2
0.26
12.8
2.49
124
26
2
0.69
34.6
1.80
90
27
2
0.12
6.1
1.97
98
28
2
0.19
9.7
2.15
108
29
2
0.30
15.0
2.10
105
30
2
0.15
7.4
2.41
121
31
2
0.64
32.2
2.46
123
32
2
0.85
42.3
1.96
98
33
2
0.52
25.9
2.05
102
34
2
0.22
11.0
1.42
71
35
2
0.37
18.3
2.31
115
36
2
0.42
21.2
2.69
134
37
2
0.34
16.8
2.34
117
38
2
0.77
38.5
0.97
49
39
2
0.29
14.7
2.11
106
40
20
15.16
75.8
19.51
98
41
2
0.20
9.9
2.20
110
42
2
0.17
8.3
2.34
117
43
2
0.27
13.3
2.37
119
44
2
0.15
7.4
2.11
106
45
100
3.36
3.4
98.33
98
46
2
0.58
28.8
1.65
82
47
2
0.07
3.5
1.55
77
-------
Method 525.1
Table 10. Minimum Detection Limits From Seven Replicates Using Liquid-Solid
Extraction C-18 Disks and an Ion Trap Mass Spectrometer
Chemical Name Minimum Detection
Limits
Acenaphytiene
0.033
Alachlor
0.092
Aldrin
0.083
Anthracene
0.086
Atrazine
0.140
Benz [a] anthracene
0.224
Benzo [b] fluoranthene
0.488
Benzo [ic] fluoranthene
0.086
Benzo[a]pyrene
0.137
Benzo [g,h,i] perylene
0.094
Butylbenzyl phthalate
0.204
Chlordane-a
0.384
Chlordane-y
0.200
Chlordane (trans-Nonachlor)
0.574
Chrysene
0.068
Dibenz [a, h] anthracene
0.144
Di-n-butyl phthalate Diethyl
0.253
phthalate
0.075
Di(2-ethylhexyl) phthalate
1.584
Di(2-ethlyhexyl) adipate
0.131
Dimethyl phthalate
0.048
Endrin
0.160
Fluorene
0.046
Heptachlor
0.144
Heptachlorepoxide
0.244
Hexachlorobenzene
0.111
Hexachlorocyclopentadiene
0.039
Indeno[l,2,3,c,d]pyrene
0.170
Lindane
0.041
Methoxychlor
0.084
PCB-mono-Cl-isomer
0.045
PCB-di-Cl-isomer
0.061
PCB-tri-Cl-isomer
0.135
PCB-tetra-Cl-isomer
0.177
PCB-penta-Cl-isomer
0.200
PCB-hepta-Cl-isomer
0.239
PCB-octa-Cl-isomer
0.133
Pentachlorophenol
47.648
Phenanthrene
0.076
Pyrene
0.064
Simazine
0.118
Toxaphene
7.763
-------
Method 525.1
TIC
100
80
60-
40-
20-
34 26
41 46
44
29
k
21
8925696
391642 15
30 I i 1 | 17
33
27
JL
Scan
R.T.
T
100
4:55
300
9:46
400
12:12
5bo
14:38
TIC
100-
80-
25
60-
40-
14
1
20-
1 ll.
Scan 600
R.T. 17:04
a/
10 11
T—1
700
19:29
JU
2513216
13
"T
800
21:55
900
24:21
35 20 I
1000
26:47
62-015-11
Figure 1. Total Ion Chromatogram of Two Nanograms of Analytes
And Five Nanograms of Surrogates and Internal Standard
-------
Method 525.1
ioo%H
— C18 Column Bleed
TOT-
Method Analytes at 2 /^g/l
1200
900
600
300
5:01 10:01 15:01 20:01
52-015-13
Figure 2. Total Ion Chromatogram from a Laboratory Blank
With an Unacceptably High Background
-------
Method 525.1
2 Liter
Separatory Funnel
125 mL
Solvent
Reservoir
Ground Glass
Stopper 14/35
LSE Cartridge
100 mL
Separatory
Funnel
125 mL
Solvent
Reservoir
Ground Glass
Stopper 14/35
LSE Cartridge
Rubber Stopper
Drying Column
(Na2S04)
1.2 cm x 40 cm
No. 18-20 Luer-lok
Syringe Needle
1 Liter
Vacuum Flask
10 mL
Graduated
Vial
52-015-14
A. Extraction Apparatus
Figure 3.
-------
Method 525.1
Source
Vacuum
1 Liter
Suction Flask
52-015-15
Figure 4. Disk Extraction Apparatus
-------
Method 525.1
Appendix
Detection Limits for Precision and Accuracy for the Analysis of
Pesticide Compounds by EPA Method 525.1
Table 7. Method 525.1 Detection Limits—507 & 508 Compounds
Target
#
%
MS
ECD-NPD
Compound
(}ig/L)
Reps
Rec
SD
MDL
MDL
Alachlor
0.2
7
73
7
0.044
0.380
Aldrin
0.2
7
33
10
0.060
0.075
Ametryn
0.1
7
68
14
0.043
2.000
Atraton
2.0
7
51
8
0.533
0.600
Atrazine
0.2
7
78
7
0.041
0.130
BHC,a
0.1
7
143
31
0.970
0.025
BHC,|3
0.1
7
76
9
0.027
0.010
BHC, 6
0.1
7
78
9
0.029
0.010
BHC,y
0.2
7
73
12
0.072
0.015
Bromacil
0.1
7
117
13
0.041
2.500
Butachlor
0.1
7
98
8
0.025
0.380
Butylate
0.1
7
78
23
0.071
0.150
Carboxin
0.1
7
65
9
0.027
0.600
Chlordane, a
0.2
7
61
11
0.069
0.002
Chlordane, y
0.2
7
61
11
0.066
0.002
Chloroneb
0.1
7
62
8
0.026
0.500
Chlorobenzilate
0.1
7
315
25
0.077
5.000
Chlorothalonil
0.1
7
77
9
0.028
0.025
Chlorpropham
0.1
7
84
9
0.028
0.500
Cycloate
0.1
7
67
14
0.043
0.025
DCPA
0.1
7
78
23
0.071
0.025
DDD, 4,4'-
0.1
7
73
14
0.045
0.003
DDE, 4,4'-
0.1
7
143
16
0.051
0.010
DDT, 4,4-
0.1
7
74
17
0.052
0.060
Diazinon
0.1
7
98
14
0.043
0.250
Dichlorvos
0.1
7
75
28
0.089
2.500
Dieldrin
2.0
7
86
4
0.265
0.020
Diphenamid
0.1
7
87
7
0.022
0.600
Disulfoton
0.1
7
75
16
0.050
0.300
Disulfoton sulfone
0.1
7
86
8
0.025
3.800
Disulfoton sulfoxide
2.0
7
131
11
0.723
0.380
Endosulfan I
0.1
7
72
10
0.031
0.015
Endosulfan II
0.1
7
101
30
0.096
0.024
Endosulfan sulfate
0.1
7
79
13
0.042
0.015
Endrin
0.2
7
85
16
0.102
0.015
Endrin aldehyde
0.1
7
92
11
0.036
0.025
EPTC
0.1
7
56
20
0.061
0.250
Ethoprop
0.1
7
152
2
0.007
0.250
Etridiazole
0.1
7
61
24
0.076
0.190
Fenamiphos
0.1
7
140
12
0.037
1.000
Fenarimol
0.1
7
136
9
0.028
0.380
Fluridone
2.0
7
105
19
1.166
3.800
Heptachlor
0.2
7
54
12
0.074
0.010
-------
Method 525.1
Table 7. Method 525.1 Detection Limits—507 & 508 Compounds
Target
#
%
MS
ECD-NPD
Compound
(Vg/L)
Reps
Rec
SD
MDL
MDL
Heptachlor epoxide
0.2
7
71
10
0.061
0.015
Hexachlorobenzene
0.2
7
80
16
0.102
0.008
Hexazinone
0.1
7
124
12
0.038
0.760
Merphos
0.1
7
119
15
0.049
0.250
Methoxychlor
0.2
7
15
3
0.020
0.050
Methyl paraoxon
0.1
7
122
11
0.036
2.500
Metolachlor
0.1
7
81
5
0.015
0.750
Metribuzin
0.1
7
49
14
0.045
0.150
Mevinphos
0.1
7
98
14
0.044
5.000
MKG-264
0.1
7
64
4
0.013
0.500
Molinate
0.1
7
64
13
0.041
0.150
Napropamide
0.1
7
89
7
0.021
0.250
Norflurazon
0.1
7
108
7
0.023
0.500
Pebulate
0.1
7
72
19
0.061
0.130
Permethrin, cis-
0.05
7
76
20
0.031
0.500
Permethrin, trans-
0.15
7
80
20
0.095
0.500
Prometon
0.1
7
78
58
0.181
0.300
Prometryn
0.1
7
98
16
0.050
0.190
Pronamide
0.1
7
73
7
0.021
0.760
Propachlor
0.2
7
92
11
0.071
0.500
Propazine
0.1
7
77
5
0.015
0.130
Simazine
0.1
7
81
8
0.026
0.075
Simetryn
0.1
7
82
34
0.108
0.250
Stirofos
0.1
7
101
8
0.025
0.760
Tebuthiuron
0.1
7
114
14
0.044
1.300
Terbacil
0.1
7
104
6
0.019
4.500
Terbufos
0.1
7
162
19
0.060
0.500
Terbutryn
0.1
7
83
12
0.038
0.250
Triademefon
0.1
7
208
84
0.264
0.650
Tricyclazole
2.0
7
150
77
4.861
1.000
Trifluralin
0.2
7
68
13
0.082
0.025
Vernolate
0.1
7
54
14
0.045
0.130
Avg
91
15
0.16
0.67
-------
Method 525.1
Table 9. Method 525.1 —Laboratory Fortified Blank Data, 1 L
Mean
Compound
Target {fig/L)
# Reps
Obser.
SD
% RSD
Accuracy
Alachlor
1.0
13
1.039
0.15
13
104
Aldrin
1.0
13
1.114
0.58
15
111
Ametryn
1.0
13
0.850
0.09
13
85
Atraton
1.0
13
0.313
0.10
13
31
Atrazine
1.0
13
0.932
0.13
14
93
BHC,a
1.0
13
1.070
0.64
12
107
BHC,|3
1.0
13
1.075
0.61
13
108
BHC, 6
1.0
13
1.136
0.66
12
114
BHC,y
1.0
13
1.105
0.67
12
110
Bromacil
1.0
13
0.879
0.21
13
88
Butachlor
1.0
13
1.126
0.27
9
113
Butylate
1.0
13
0.843
0.23
18
84
Carboxin
1.0
13
0.757
0.07
16
76
Chlordane, a
1.0
13
1.017
0.69
9
102
Chlordane, y
1.0
13
1.144
0.61
9
114
Chlorneb
1.0
13
1.018
0.60
10
102
Chlorobenzilate
1.0
13
1.211
0.65
11
121
Chlorothalonil
1.0
13
1.211
0.65
13
121
Chlorpropham
1.0
13
1.121
0.67
15
112
Cycloate
1.0
13
0.639
0.24
10
64
DCPA
1.0
13
0.822
0.16
11
82
DDD, 4,4'-
1.0
13
1.084
0.63
9
108
DDE, 4,4'-
1.0
13
1.221
0.60
13
122
DDT, 4,4'-
1.0
13
1.128
0.66
13
113
Diaznion
1.0
13
1.335
0.84
13
134
Dichlorvos
1.0
13
0.749
0.09
28
75
Dieldrin
1.0
13
0.819
0.12
11
82
Diphenamid
1.0
13
1.383
0.79
12
138
Disulfoton
1.0
13
0.978
0.12
16
98
Disulfoton sulfone
1.0
9
0.880
0.11
17
88
Disulfoton sulfoxide
1.0
13
0.490
0.47
19
49
Endosulfan I
1.0
13
1.229
1.47
24
123
Endosulfan II
1.0
13
1.358
0.67
12
136
Endosulfan sulfate
1.0
13
1.194
0.56
15
119
Endrin
1.0
13
1.223
0.66
11
122
Endrin aldehyde
1.0
13
1.331
0.77
10
133
EPTC
1.0
13
1.159
0.70
14
116
Ethoprop
1.0
13
1.134
0.19
29
113
Etridiazole
1.0
13
0.911
0.11
12
91
Fenamiphos
1.0
13
1.088
0.58
17
109
Fenarimol
1.0
13
1.074
0.47
11
107
Fluridone
1.0
13
1.108
0.20
14
111
Heptachlor
1.0
13
1.102
0.22
14
110
Heptachlor epoxide
1.0
13
1.218
0.63
12
122
Hexachlorobenzene
1.0
13
1.024
0.65
9
102
Hexazinone
1.0
13
0.988
0.60
24
99
Merphos
1.0
13
0.955
0.28
10
95
Methoxychlor
1.0
13
1.182
0.31
20
118
-------
Method 525.1
Table 9. Method 525.1—Laboratory Fortified Blank Data, 1 L
Mean
Compound
Target (pg/L)
# Reps
Obser.
SD
% RSD
Accuracy
Methyl paraoxon
1.0
13
2.334
0.83
34
233
Metolachlor
1.0
13
0.888
0.18
14
89
Metribuzin
1.0
13
1.043
0.15
13
104
Mevinphos
1.0
13
0.727
0.13
18
73
MKG-264
1.0
13
0.822
0.13
21
82
Molinate
1.0
13
0.751
0.19
12
75
Napropamide
1.0
13
0.827
0.18
12
83
Norflurazon
1.0
13
0.972
0.12
12
97
Pebulate
1.0
13
1.043
0.15
11
104
Permethrin, cis-
1.0
13
1.123
0.24
16
112
Permethrin, trans-
1.0
13
0.860
0.96
18
86
Prometon
1.0
13
1.124
0.22
11
112
Prometryn
1.0
13
0.562
0.11
8
56
Pronamide
1.0
13
1.118
0.13
18
112
Propachlor
1.0
13
0.932
0.13
14
93
Propazine
1.0
13
2.179
0.90
14
218
Simazine
1.0
13
0.853
0.20
14
85
Simetryn
1.0
13
0.708
0.06
9
71
Stirofos
1.0
13
1.043
0.21
13
104
Tebuthiuron
1.0
13
1.036
0.23
30
104
Terbacil
1.0
13
1.119
0.18
17
112
Terbufos
1.0
13
0.913
0.13
13
91
Terbutryn
1.0
13
0.908
0.10
13
91
Triademefon
1.0
13
1.172
0.19
15
117
Tricyclazole
1.0
13
0.931
0.42
54
93
Trifluralin
1.0
13
2.215
0.78
15
221
Vernolate
1.0
13
0.901
0.18
16
90
Avg
1.05
0.40
15
105
------- |