EPA
United States Environmental Protection Agency
Office of Water Regulations and Standards
Industrial Technology Division
Office of Water
July 1989
Method 1618: Organo-halide Pesticides,
Organo-phosphorus Pesticides, and
Phenoxy-acid Herbicides by Wide Bore
Capillary Column Gas Chromatography
with Selective Detectors
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Introduction
Method 1618 was developed by the Industrial Technology
Division (ITD) within the United States Environmental
Protection Agency's (USEPA) Office of Water Regulations and
Standards (OURS) to provide improved precision and accuracy of
analysis of pollutants in aqueous and solid matrices. The ITD
is responsible for development and promulgation of nationwide
standards setting limits on pollutant levels in industrial
discharges.
Method 1618 is a wide bore capillary column gas chromatography
method for analysis of organo-halide and organo-phosphorus
pesticides, phenoxy-acid herbicides and herbicide esters, and
other compounds amenable to extraction and analysis by wide
bore capillary column gas chromatography with halogen-specific
and organo-phosphorus detectors.
Questions concerning the method or its application should be
addressed to:
W. A. Telliard
USEPA
Office of Water Regulations and Standards
401 M Street SU
Washington, DC 20460
202/382-7131
OR
USEPA OURS
Sample Control Center
P.O. Box 1407
Alexandria, Virginia 22313
703/557-5040
Publication date: July 1989
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Method 1618 Revision A July 1989
Organo-halide Pesticides, Organo-phosphorus Pesticides, and
Phenoxy-acid Herbicides by Wide Bore Capillary Column
Gas Chromatography with Selective Detectors
1 SCOPE AND APPLICATION
1.1 This method is designed to meet the survey
requirements of the USEPA ITD. The method
is used to determine the organo-halide
pesticides and poI/chlorinated biphenyls
(PCB's), the organo-phosphorus pesticides,
and the phenoxyacid herbicides and
herbicide esters, associated with the
Clean Water Act (as amended 1987); the
Resource Conservation and Recovery Act (as
amended 1986); the Comprehensive
Environmental Response, Compensation and
Liability Act (as amended 1986); and other
compounds amenable to extraction and
analysis by automated, wide bore capillary
column gas Chromatography (GC) with
halogen specific and organo-phosphorus
detectors.
1.2 The chemical compounds listed in Tables 1
3 may be determined in waters, soils,
sediments, and sludges by this method.
The method is a consolidation of EPA
Methods 608, 608.1, 614, 615, 617, 622,
and 701. For waters, the sample
extraction and concentration steps are
essentially the same as in these methods.
However, the extraction and concentration
steps have been extended to other sample
matrices. The method should be applicable
to other pesticides and herbicides. The
quality assurance/quality control require-
ments in Section 8.6 of this method give
the steps necessary to determine its
applicability.
1.3 When this method is applied to analysis of
unfamiliar samples, compound identity
shall be supported by at least one
additional qualitative technique. This
method describes analytical conditions for
a second gas chromatographic column that
can be used to confirm measurements made
with the primary column. Gas
chromatography-mass spectrometry (GCMS)
can be used to confirm compounds in
extracts produced by this method when
analyte levels are sufficient.
1.4 The detection limits of this method are
usually dependent on the level of
interferences rather than instrumental
limitations. The limits in Tables A 6
typify the minimum quantities that can be
detected with no interferences present.
1.5 This method is for use by or under the
supervision of analysts experienced in the
use of a gas chromatograph and in the
interpretation of gas chromatographic
data. Each laboratory that uses this
nethod must demonstrate the ability to
generate acceptable results using the
procedure in Section 8.2.
2 SUMMARY OF METHOD
2.1 Extraction
2.1.1 The percent solids content of a sample is
determined.
2.1.2 Aqueous samples containing 1 - 30 percent
solids - The sample is diluted to one
percent solids, if necessary. The
pesticides and PCB's are extracted from a
one liter sample with methylene chloride
using continuous extraction techniques.
For the herbicides, the pH of the sample
is raised to 12 - 13 to hydrolyze esters,
the sample is back-extracted to remove
basic and neutral species, the pH is then
reduced to less than 2, and the sample is
extracted with diethyl ether using
separatory funnel techniques.
2.1.3 Samples containing greater than 30 percent
solids -- The sample is extracted with
acetonitrile and then methylene chloride
using ultrasonic techniques. The extract
is back extracted with two percent (w/v)
sodium sulfate in reagent water to remove
water soluble interferences and residual
acetonitrile. Samples in which phenoxy-
acid herbicides are to be determined are
acidified prior to extraction.
2.2 Concentration and cleanup -- For samples
in which pesticides are to be determined,
each extract is dried over sodium sulfate,
concentrated using a Kuderna-Danish
evaporator, cleaned up (if necessary)
using gel permeation Chromatography (GPC),
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and/or adsorption chromatography, and/or
solid phase extraction, and then re-
concentrated to one ml. Sulfur is removed
from the extract, if required. For
samples in which the herbicides are to be
determined, each extract is dried over
acidified sodium sulfate and the acids are
derivatized to form the methyl esters.
The solution containing the methyl esters
is cleaned up (if necessary) using
adsorption chromatography and concentrated
to one ml.
2.3 Gas chromatography -- A one uL aliquot of
the extract is injected into the gas
chromatograph (GC). The compounds are
separated on a wide bore, fused silica
capillary column. The organo-halide
compounds, including the derivatized
phenoxy-acid herbicides, are detected by
an electron capture, microcoulometric, or
electrolytic conductivity detector. The
phosphorus containing compounds are
detected using a flame photometric
detector.
2.4 Identification of a pollutant (qualitative
analysis) is performed by (1) comparing
the GC retention times of the compound on
two dissimilar columns with the respective
retention times of an authentic standard,
and (2) comparing the concentrations of
the compound determined on the primary and
confirmatory GC systems. Compound
identity is confirmed when the retention
times and amounts agree within their
respective windows.
2.5 Quantitative analysis is performed by
using an authentic standard to produce a
calibration factor or calibration curve,
and using the calibration data to
determine the concentration of a pollutant
in the extract. The concentration in the
sample is calculated using the sample
weight or volume and the extract volume.
2.6 The quality of the analysis is assured
through reproducible calibration and
testing of the extraction and GC systems.
3 CONTAMINATION AND INTERFERENCES
3.1 Solvents, reagents, glassware, and other
sample processing hardware may yield
artifacts and/or elevated baselines
causing misinterpretation of chroma-
tograms. All materials used in the
analysis shall be demonstrated to be free
from interferences under the conditions of
analysis by running method blanks as
described in Section 8.5.
3.2 Glassware and, where possible, reagents
are cleaned by solvent rinse and baking at
450 °C for one hour minimum in a muffle
furnace or kiln. Some thermally stable
materials, such as PCBs, may not be
eliminated by this treatment and thorough
rinsing with acetone and pesticide quality
hexane may be required.
3.3 Specific selection of reagents and
purification of solvents by distillation
in all-glass systems may be required.
3.4 Interference by phthaiate esters can pose
a major problem in pesticide analysis when
using the electron capture detector.
Phthalates usually appear in the
chromatogram as large, late eluting peaks.
Phthalates may be leached from common
flexible plastic tubing and other plastic
materials during the extraction and clean-
up processes. Cross-contamination of
clean glassware routinely occurs when
plastics are handled during extraction,
especially when solvent wetted surfaces
are handled. Interferences from
phthalates can best be minimized by
avoiding the use of plastics in the
laboratory, or by using a microcoulometric
or electrolytic conductivity detector.
3.5 The acid forms of the herbicides are
strong acids that react readily with
alkaline substances and can be lost during
analysis. Glassware and glass wool must
be acid rinsed with dilute hydrochloric
acid and the sodium sulfate must be
acidified with sulfuric acid prior to use.
3.6 Organic acids and phenols cause the most
direct interference with the herbicides.
Alkaline hydrolysis and subsequent
extraction of the basic solution can
remove many hydrocarbons and esters that
may interfere with the herbicide analysis.
3.7 Interferences coextracted from samples
will vary considerably from source to
source, depending on the diversity of the
site being sampled. The cleanup
procedures given in this Method can be
used to overcome many of these
interferences, but unique samples may
require additional cleanup to achieve the
minimum levels given in Tables 4-6.
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SAFETY
APPARATUS AND MATERIALS
4.1 The toxicity or carcinogenic!ty of each
compound or reagent used in this method
has not been precisely determined;
however, each chemical compound should be
treated as a potential health hazard.
Exposure to these compounds should be
reduced to the lowest possible level. The
laboratory is responsible for maintaining
a current awareness file of OSHA
regulations regarding the safe handling of
the chemicals specified in this method. A
reference file of material handling sheets
should also be made available to all
personnel involved in these analyses.
Additional information on laboratory
safety can be found in References 1-3.
4.2 The following compounds covered by this
method have been tentatively classified as
known or suspected human or mammalian
carcinogens: 4,4'-DDD, 4,4'-DDT, the BHCs
and the PCBs. Primary standards of these
compounds shall be prepared in a hood, and
a NIOSH/MESA approved toxic gas respirator
should be worn when high concentrations
are handled.
4.3 Diazomethane is a toxic carcinogen which
can decompose or explode under certain
conditions. Solutions decompose rapidly
in the presence of solid materials such as
copper powder, calcium chloride, and
boiling chips. The following operations
may cause explosion: heating above 90 °C;
use of grinding surfaces such as ground
glass joints, sleeve bearings, and glass
stirrers; and storage near alkali metals.
Diazomethane shall be used only behind a
safety screen in a well ventilated hood
and should be pipetted with mechanical
devices only.
4.4 Mercury vapor is highly toxic. If mercury
is used for sulfur removal, all operations
involving mercury shall be performed in a
hood.
4.5 Unknown samples may contain high
concentrations of volatile toxic
compounds. Sample containers should be
opened in a hood and handled with gloves
that will prevent exposure. The oven used
for sample drying to determine percent
moisture should be located in a hood so
that vapors from samples do not create a
health hazard in the laboratory.
5.1 Sampling equipment for discrete or
composite sampling.
5.1.1 Sample bottles and caps
5.1.1.1 Liquid samples (waters, sludges and
similar materials that contain less than
five percent solids) -- Sample bottle,
amber glass, 1 liter or 1 quart, with
screw cap.
5.1.1.2 Solid samples (soils, sediments, sludges,
filter cake, compost, and similar
materials that contain more than five
percent solids) -- Sample bottle, wide
mouth, amber glass, 500 mL minimum.
5.1.1.3 If amber bottles are not available,
samples shall be protected from light.
5.1.1.4 Bottle caps -- Threaded to fit sample
bottles. Caps shall be lined with Teflon.
5.1.1.5 Cleaning
5.1.1.5.1 Bottles are detergent water washed, then
solvent rinsed or baked at 450 °C for one
hour minimum before use.
5.1.1.5.2 Liners are detergent water washed, then
reagent water and solvent rinsed, and
baked at approx 200 °C for one hour
minimum prior to use.
5.1.2 Compositing equipment -- Automatic or
manual compositing system incorporating
glass containers cleaned per bottle
cleaning procedure above. Sample
containers are kept at 0 - 4 °C during
sampling. Glass or Teflon tubing only
shall be used. If the sampler uses a
peristaltic pump, a minimum length of
compressible silicone rubber tubing may be
used in the pump only. Before use, the
tubing shall be thoroughly rinsed with
methaneI, followed by repeated rinsings
with reagent water to minimize sample
contamination. An integrating flow meter
is used to collect proportional composite
samples.
5.2 Equipment for determining percent moisture
5.2.1 Oven, capable of being temperature
controlled at 110 ±5 *C.
5.2.2 Dessicator
5.2.3 Crucibles, porcelain
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5.2.4 Weighing pans, aluminum
5.3 Extraction equipment
5.3.1 Equipment for ultrasonic extraction
5.3.1.1 Sonic disrupter -- 375 watt with pulsing
capability and 1/2 or 3/4 in. disrupter
horn (Ultrasonics, Inc. Model 375C, or
equivalent).
5.3.1.2 Sonabox (or equivalent), for use with
disrupter.
5.3.2 Equipment for liquid-liquid extraction
5.3.2.1 Continuous liquid-liquid extractor
Teflon or glass connecting joints and
stopcocks without lubrication, 1.5-2
liter capacity (Hershberg-Wolf Extractor,
Cat-Glass, Costa Mesa, California, 1000 or
2000 ml continuous extractor, or
equivalent).
5.3.2.2 Round-bottom flask, 500 ml, with heating
mantle.
5.3.2.3 Condenser, Graham, to fit extractor.
5.3.2.4 pH meter, with combination glass
electrode.
5.3.2.5 pH paper, wide range (Hydrion Papers, or
equivalent).
5.3.3 Separatory funnels -- 250, 500, 1000, and
2000 ml, with Teflon stopcocks.
5.3.4 Filtration apparatus
5.3.4.1 Glass powder funnels -- 125 - 250 ml
5.3.4.2 Filter paper for above (Whatman 41, or
equivalent)
5.3.5 Beakers
5.3.5.1 1.5 - 2 liter, calibrated to one liter
5.3.5.2 400 - 500 mL
5.3.6 Spatulas -- Stainless steel or Teflon
5.3.7 Drying column -- 400 mm x 15 to 20 mm i.d.
Pyrex chromatographic column equipped with
coarse glass frit or glass wool plug.
5.3.7.1 Pyrex glass wool -- Solvent extracted or
baked at 450 °C for one hour minimum.
5.4 Evaporation/concentration apparatus
5.4.1
5.4.1.1
5.4.1.2
5.4.1.3
5.4.1.4
5.4.1.5
5.4.1.5.1
5.4.1.5.2
5.4.2
5.4.3
5.4.4
5.5
5.5.1
5.5.2
5.6
5.6.1
5.6.1.1
Kuderna-Danish (K-D) apparatus
Evaporation flask -- 500 ml (Kontes K-
570001-0500, or equivalent), attached to
concentrator tube with springs (Kontes K-
662750-0012).
Concentrator tube -- 10 ml, graduated
(Kontes K-570050-1025, or equivalent) with
calibration verified. Ground glass
stopper (size 19/22 joint) is used to
prevent evaporation of extracts.
Snyder column -- Three ball macro (Kontes
K-503000-0232, or equivalent).
Snyder column -- Two ball micro (Kontes K-
469002-0219, or equivalent).
Boiling chips
Glass or silicon carbide -- Approx 10/40
mesh, extracted with methylene chloride
and baked at 450 "C for one hr minimum.
Teflon (optional)
methylene chloride.
Extracted with
Water bath -- Heated, with concentric ring
cover, capable of temperature control (±2
°C), installed in a fume hood.
Nitrogen evaporation device -- Equipped
with heated bath that can be maintained at
35 - 40 °C (N-Evap, Organomation
Associates, Inc., or equivalent).
Sample vials -- Amber glass, 1 - 5 ml with
Teflon-lined screw or crimp cap, to fit GC
autosampler.
Balances
Analytical -- Capable of weighing 0.1 rug.
Top loading -- Capable of weighing 10 mg.
Apparatus for sample cleanup.
Automated gel permeation chromatograph
(Analytical Biochemical Labs, Inc,
Columbia, MO, Model GPC Autoprep 1002, or
equivalent).
Column -- 600 - 700 mn x 25 mm i.d.,
packed with 70 g of SX-3 Bio-beads (Bio-
Rad Laboratories, Richmond, CA, or
equivalent).
5.6.1.2 Syringe, 10 ml, with Luer fitting.
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5.6.1.3 Syringe filter holder, stainless steel,
and glass fiber or Teflon filters (Gelman
Acrodisc-CR, 1-5 micron, or equivalent).
5.6.1.4 UV detectors -- 254-mu, preparative or
semi-prep flow cell: (Isco, Inc., Type 6;
Schmadzu, 5 mm path length; Beckman-Altex
152U, 8 uL micro-prep flow cell, 2 mm
path; Pharmacia UV-1, 3 mm flow cell; LDC
Milton-Roy UV-3, monitor #1203; or
equivalent).
5.6.2 Vacuum system and cartridges for solid
phase extraction (SPE)
5.6.2.1 Vacuum system -- Capable of achieving 0.1
bar (house vacuum, vacuum pump, or water
aspirator), with vacuum gauge.
5.6.2.2 VacElute Manifold (Analytichem
International, or equivalent).
5.6.2.3 Vacuum trap -- Hade from 500 ml sidearm
flask fitted with single hole rubber
stopper and glass tubing.
5.6.2.4 Rack for holding 50 ml volumetric flasks
in the manifold.
5.6.2.5 Column -- Mega Bond Elut, Non-polar, C18
Octadecyl, 10 g/60 ml (Analytichem
International Cat. No. 607H060, or
equivalent).
5.6.3 Chromatographic column -- 400 mm x 22 mm
i.d., with Teflon stopcock and coarse frit
(Kontes K-42054, or equivalent).
5.6.4 Sulfur removal tubes -- 40 50 mL bottle
or test tube with Teflon lined screw cap.
5.7 Centrifuge apparatus
5.7.1 Centrifuge -- Capable of rotating 500 ml
centrifuge bottles or 15 mL centrifuge
tubes at 5,000 rpm minimum
5.7.2 Centrifuge bottles -- 500 ml, with screw
caps, to fit centrifuge
5.7.3 Centrifuge tubes -- 12-15 mL, with screw
caps, to fit centrifuge
5.7.4 Funnel, Buchner, 15 cm.
5.7.4.1 Flask, filter, for use with Buchner funnel
5.7.4.2 Filter paper, 15 cm (Whatman #41, or
equivalent).
5.8 Oerivatization apparatus -- Diazald kit
with clear seal joints for generation of
diazomethane (Aldrich Chemical Co.
210,025-0, or equivalent).
5.9 Miscellaneous glassware
5.9.1 Pipettes, glass, volumetric, 1.00, 5.00,
and 10.0 mL
5.9.2 Syringes, glass, with Luerlok tip, 0.1,
1.0 and 5.0 mL. Needles for syringes, two
inch, 22 gauge.
5.9.3 Volumetric flasks, 10.0, 25.0, and 50.0 mL
5.9.4 Scintillation vials, glass, 20 - 50 mL,
with Teflon-lined screw caps.
5.10 Gas chromatographs -- Two GC's shall be
employed. Both shall have split less or
on-column simultaneous automated injection
into separate capillary columns with a
halide specific detector or flame
photometric detector at the end of each
column, temperature program with
isothermal holds, data system capable of
recording simultaneous signals from the
two detectors, and shall meet all of the
performance specifications in Section 14.
5.10.1
5.10.1.1
5.10.1.2
5.10.1.3
5.10.2
GC columns -- Bonded phase fused silica
capillary
Primary for organo-halide compounds -- 30
±3 m x 0.5 ±0.05 mm i.d. DB-608, or
equivalent).
Primary for organo-phosphate compounds --
DB-1 (or equivalent) with same dimensions
as column for organo-halide compounds.
Confirmatory -- DB-1701, or equivalent,
with same dimensions as primary column.
Data system -- Shall collect and record GC
data, store GC runs on magnetic disk or
tape, process GC data, compute peak areas,
store calibration data including retention
times and calibration factors, identify GC
peaks through retention times, compute
concentrations, and generate reports.
5.10.2.1 Data acquisition -- GC data shall be
collected continuously throughout the
analysis and stored on a mass storage
device.
5.10.2.2 Calibration factors and calibration curves
-- The data system shall be used to record
and maintain lists of calibration factors,
and multi-point calibration curves
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(Section 7). Computations of relative
standard deviation (coefficient of
variation) are used for testing
calibration linearity. Statistics on
initial (Section 8.2) and ongoing (Section
14.6) performance shall be computed and
maintained.
5.10.2.3 Data processing -- The data system shall
be used to search, locate, identify, and
quantify the compounds of interest in each
GC analysis. Software routines shall be
employed to compute and record retention
times and peak areas. Displays of
chromatograms and library comparisons are
required to verify results.
5.10.3 Detectors
5.10.3.1 Halide specific -- Electron capture or
electrolytic conductivity (Hicoulometric,
Hall, O.I., or equivalent), capable of
detecting 8 pg of aldrin under the
analysis conditions given in Table 4.
5.10.3.2 Flame photometric -- Capable of detecting
11 pg of ma I athi on under the analysis
conditions given in Table 5.
5.10.4 Chromatographs may be configured in one of
two ways: (1) Two halide specific
detectors (HSD's) in one GC; two flame
photometric detectors (FPD's) in the
other. With this configuration, the
primary and confirmatory columns and
detectors are in the same GC. (2) One HSD
and one FPD in each GC. With this
configuration, the primary columns and
detectors are in one GC, the confirmatory
columns and detectors are in the other.
6 REAGENTS AND STANDARDS
6.1 Sample preservation -- Sodium thiosulfate
(ACS), granular.
6.2 pH adjustment
6.2.1 Sodium hydroxide -- Reagent grade.
6.2.1.1 Concentrated solution (10N) -- Dissolve 40
g NaOH in 100 ml reagent water.
6.2.1.2 Dilute solution (0.1H) -- Dissolve 4 g
NaOH in 1 liter of reagent water.
6.2.2 Sulfuric acid (1 + 1) -- Reagent grade, 6N
in reagent water. Slowly add 50 ml H.SO,
(specific gravity 1.84) to 50 ml reagent
water.
6.2.3 Potassium hydroxide 37 w/v percent.
Dissolve 37 g KOH in 100 mL reagent water.
6.3 Solution drying and back extraction
6.3.1 Sodium sulfate, reagent grade, granular
anhydrous (Baker 3375, or equivalent),
rinsed with methylene chloride (20 mL/g),
baked at 450 °C for one hour minimum,
cooled in a dessicator, and stored in a
pre-cleaned glass bottle with screw cap
which prevents moisture from entering.
6.3.2 Acidified sodium sulfate -- Add 0.5 mL
H.SO, and 30 mL ethyl ether to 100 g
sodium sulfate. Mix thoroughly. Allow
the ether to evaporate completely.
Transfer the mixture to a clean container
and store at 110 ±5 °C.
6.3.3 Sodium sulfate solution -- Two percent
(w/v) in reagent water, pH adjusted to 8.5
- 9.0 with KOH or H2S04.
6.3.4 Sodium sulfate, reagent grade, powdered
anhydrous (Baker 73898, or equivalent),
rinsed with methylene chloride (20 mL/g),
baked at 450 °C for one hour minimum,
cooled in a dessicator, and stored in a
pre-cleaned glass bottle with screw cap
which prevents moisture from entering.
NOTE: The powdered sodium sulfate is used
only in ultrasonic extraction of samples
containing 30 percent solids or greater,
and not for drying of sample extracts.
Use of granular sodium sulfate during
ultrasonic extraction may lead to poor
recovery of analytes.
6.4 Solvents -- Methylene chloride, hexane,
ethyl ether, acetone, acetonitrile,
isooctane, and methanol; pesticide
quality; lot certified to be free of
interferences.
6.4.1 Ethyl ether must be shown to be free of
peroxides before it is used, as indicated
by EM Laboratories Quant Test Strips
(Scientific Products P1126-8, or
equivalent). Procedures recommended for
removal of peroxides are provided with the
test strips. After cleanup, 20 mL of
ethyl alcohol is added to each liter of
ether as a preservative.
6.5 GPC calibration solution -- Solution
containing 300 mg/mL corn oil, 15 mg/mL
bis(2-ethylhexyl) phthalate, 1.4 mg/mL
pentachlorophenol, 0.1 mg/mL perylene, and
0.5 mg/mL sulfur
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6.6 Sample cleanup
6.6.1 Florisil - PR grade, 60/100 mesh,
activated at 650 - 700 °C, stored in the
dark in glass container with Teflon-lined
screw cap. Activate at 130 °C for 16
hours minimum immediately prior to use.
Alternatively, 500 mg cartridges (J.T.
Baker, or equivalent) may be used.
6.6.2 Solid phase extraction
6.6.2.1 SPE cartridge calibration solution --
2,4,6-trichlorophenol, 0.1 ug/mL in
acetone.
6.6.2.2 SPE elution solvent - Methylene
chloride:acetonitrile:hexane (50:3:47).
6.6.3 Alumina, neutral, Brockman Activity I, 80
- 200 mesh (Fisher Scientific Certified,
or equivalent). Heat for 16 hours at 400
- 450 °C. Seal and cool to room
temperature. Add 7 percent w/w reagent
water and mix for 10 - 12 hours. Keep
bottle tightly sealed.
6.6.4 Silicic acid, 100 mesh
6.6.5 Sulfur removal -- Mercury (triple
distilled), copper powder (bright, non-
oxidized), or TEA sodium sulfite. If
mercury is used, observe the handling
precautions in Section 4.
6.7 Derivatization -- Diazald reagent [N-
methyl-(N-nitroso-p-toluene sulfanamide)],
fresh and high purity (Aldrich Chemical
Co.)
6.8 Reference matrices
6.8.1 Reagent water -- Water in which the
compounds of interest and interfering
compounds are not detected by this method.
6.8.2 High solids reference matrix -- Playground
sand or similar material in which the
compounds of interest and interfering
compounds are not detected by this method.
May be prepared by extraction with
methylene chloride and/or baking at 450 °C
for 4 hours minimum.
6.9 Standard solutions -- Purchased as
solutions or mixtures with certification
to their purity, concentration, and
authenticity, or prepared from materials
of known purity and composition. If
compound purity is 96 percent or greater,
the weight may be used without correction
to compute the concentration of the
standard. When not being used, standards
are stored in the dark at -20 to -10 °C in
screw-capped vials with Teflon-lined lids.
A mark is placed on the vial at the level
of the solution so that solvent
evaporation loss can be detected. The
vials are brought to room temperature
prior to use. Any precipitate is
redissolved and solvent is added if
solvent loss has occurred.
6.10 Preparation of stock solutions -- Prepare
in isooctane per the steps below. Observe
the safety precautions in Section 4.
6.10.1 Dissolve an appropriate amount of assayed
reference material in solvent. For
example, weigh 10 mg aldrin in a 10 ml
ground glass stoppered volumetric flask
and fill to the mark with isooctane.
After the aldrin is completely dissolved,
transfer the solution to a 15 ml vial with
Teflon-lined cap.
6.10.2 Stock standard solutions should be checked
for signs of degradation prior to the
preparation of calibration or performance
test standards. Quality control check
samples that can be used to determine the
accuracy of calibration standards are
available from the USEPA, Environmental
Monitoring and Support Laboratory,
Cincinnati, Ohio 45268.
6.10.3 Stock standard solutions shall be replaced
after six months, or sooner if comparison
with quality control check standards
indicates a change in concentration.
6.11 Secondary mixtures -- Using stock
solutions (Section 6.10), prepare mixtures
at the levels required for calibration and
calibration verification (Sections 7.3 and
14.5), for initial and ongoing precision
and recovery (Sections 8.2 and 14.6), and
for spiking into the sample matrix
(Section 8.4).
6.12 Surrogate spiking solutions
6.12.1 Chlorinated pesticides -- Prepare dibutyl
chlorendate at a concentration of 2 ug/mL
in acetone.
6.12.2 Phosphorus containing pesticides
Prepare tributyl phosphate and triphenyl
phosphate each at a concentration of 2
ug/ml in acetone.
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6.12.3 Phenoxyacid herbicides -- Prepare 2,4-
dichlorophenyI acetic acid at a
concentration of 2 ug/mL in acetone.
6.13 DDT and endrin decomposition solution --
Prepare a solution containing endrin at a
concentration of 1 ug/mL and DDT at a
concentration of 2 ug/mL.
6.14 Stability of solutions -- All standard
solutions (Sections 6.9 - 6.13) shall be
analyzed within 48 hours of preparation
and on a monthly basis thereafter for
signs of degradation. Standards will
remain acceptable if the peak area remains
within ±15 percent of the area obtained in
the initial analysis of the standard.
7 SETUP AND CALIBRATION
7.1 Configure the GC systems in one of the two
ways given in Section 5.10.4 and establish
the operating conditions in Tables 4-5.
7.2 Attainment of Method Detection Limit (MDL)
and DDT/Endrin decomposition requirements
-- Determine that each column/detector
system meets the MDL's (Tables 4-6) and
that the organohalide systems meet the DDT
and Endrin decomposition test (Section
14.4).
7.3 Calibration
7.3.1 Calibration solutions -- Prepare
calibration standards at a minimum of
three concentration levels for each
compound of interest by adding volumes of
one or more stock standards to a
volumetric flask and diluting to volume
with hexane or isooctane. The lowest
concentration solution should be at a
concentration near, but above, the MDL's
(Tables 4-6). The highest concentration
solution should be near, but below, the
maximum linear range of the analytical
system. The other concentration(s) should
be ideally equally spaced on a logarithmic
scale between the lowest and highest
concentration solutions. The ratio
between the highest and lowest
concentration should be 100 or greater.
Note: the GC retention time overlap
between analytes requires that the
compounds separated and analyzed as
groups. Divide the single component
analytes into three or four calibration
groups each for the organo-halide and
organo-phosphorus compounds with an
approximately equal number of analytes per
group. The compound pairs specified for
GC resolution (Section 14.3) shall be in
the same group. PCB 1254 or 1260 and
Toxaphene are calibrated separately.
7.3.2 Inject the calibration solutions into the
GC column/detector pairs appropriate for
the mixture, beginning with the lowest
level mixture and proceeding to the
highest. For each compound, compute and
store, as a function of the concentration
injected, the retention time and peak area
on each column/detector system (primary
and confirmatory). For the multicomponent
analytes (PCB's, toxaphene), store the
retention time and peak area for the five
largest peaks.
7.3.3 Retention time -- The polar nature of some
analytes causes the retention time to
decrease as the quantity injected
increases. To compensate this effect, the
retention time for compound identification
is correlated with the analyte level.
7.3.3.1 If the difference between the maximum and
minimum retention times for any compound
is less than five seconds over the
calibration range, the retention time for
that compound can be considered constant
and an average retention time may be used
for compound identification.
7.3.3.2 Retention time calibration curve
(retention time vs amount) -- If the
retention time for a compound in the
lowest level standard is more than five
seconds greater than the retention time
for the compound in the highest level
standard, a retention time calibration
curve shall be used for identification of
that compound.
7.3.4 Calibration factor (ratio of area to
amount injected)
7.3.4.1 Compute the coefficient of variation
(relative standard deviation) of the
calibration factor over the calibration
range for each compound on each
column/detector system.
7.3.4.2 Linearity -- If the calibration factor for
any compound is constant (Cv < 20 percent)
over the calibration range, an average
calibration factor nay be used for that
compound; otherwise, the complete
calibration curve (area vs amount) for
that compound shall be used.
8
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7.4 Combined OC standards -- To preclude
periodic analysis of all of the individual
calibration groups of compounds (Section
7.3.1), the GC systems are calibrated with
combined solutions as a final step. Not
all of the compounds in these standards
will be separated by the GC columns used
in this method. Retention times and
calibration factors are verified for the
compounds that are resolved, and
calibration factors are obtained for the
unresolved peaks. These combined OC
standards are prepared at the level of the
mid-range calibration standard (7.3.1).
7.4.1 Analyze the combined OC standards on their
respective column/detector pairs.
7.4.1.1 For those compounds that exhibit a single,
resolved GC peak, the retention time shall
be within ±5 seconds of the retention time
of the peak in the medium level
calibration standard (Section 7.3.1), and
the calibration factor using the primary
column shall be within ±20 percent of the
calibration factor in the medium level
standard (Section 7.3.4).
7.4.1.2 For the peaks containing two or more
compounds, compute and store the retention
times at the peak maxima on both columns
(primary and confirmatory), and also
compute and store the calibration factors
on both columns. These results will be
used for calibration verification (Section
14.2 and 14.5) and for precision and
recovery studies (Section 14.6).
7.5 Florisil calibration -- The cleanup
procedure in Section 11 utilizes florisil
colim chromatography. Florisil from
different batches or sources may vary in
adsorptive capacity. To standardize the
amount of florisil that is used, the use
of the lauric acid value (Reference 4) is
suggested. The referenced procedure
determines the adsorption of lauric acid
(in mg/g of florisil) from hexane
solution. The amount of florisil to be
used for each column is calculated by
dividing 110 by this ratio and multiplying
by 20 g.
8 QUALITY ASSURANCE/QUALITY CONTROL
8.1 Each laboratory that uses this method is
required to operate a formal quality
assurance program (Reference 5). The
minimum requirements of this program
consist of en initial demonstration of
laboratory capability, an ongoing analysis
of standards and blanks as tests of
continued performance, and analysis of
matrix spike and matrix spike duplicate
(HS/HSO) samples to assess accuracy and
precision. Laboratory performance is
compared to established performance
criteria to determine if the results of
analyses meet the performance
characteristics of the method. If the
method is to be applied routinely to
samples containing high solids with very
little moisture (e.g., soils, compost),
the high solids reference matrix (Section
6.8.2) is substituted for the reagent
water (Section 6.8.1) in all performance
tests, and the high solids method (Section
10) is used for these tests.
8.1.1 The analyst shall make an initial
demonstration of the ability to generate
acceptable accuracy and precision with
this method. This ability is established
as described in Section 8.2.
8.1.2 The analyst is permitted to modify this
method to improve separations or lower the
costs of measurements, provided all
performance requirements are met. Each
time a modification is made to the method
or a cleanup procedure is added, the
analyst is required to repeat the
procedure in Section 8.2 to demonstrate
method performance.
8.1.3 The laboratory shall spike all samples
with at least one surrogate compound to
monitor method performance. This test is
described in Section 8.3. When results of
these spikes indicate atypical method
performance for samples, the samples are
diluted to bring method performance within
acceptable limits (Section 17).
8.1.4 The laboratory shall, on an ongoing basis,
demonstrate through calibration
verification and the analysis of the
combined OC standard (Section 7.4) that
the analysis system is in control. These
procedures are described in Sections 14.1,
14.5, and 14.6.
8.1.5 The laboratory shall maintain records to
define the quality of data that is
generated. Development of accuracy
statements is described in Section 8.4.
8.1.6 Analyses of blanks are required to
demonstrate freedom from contamination.
-------
The procedures and criteria for analysis
of a blank are described in Section 8.5.
8.1.7 Other analytes may be determined by this
method. The procedure for establishing a
preliminary quality control limit for a
new analyte is given in Section 8.6.
8.2 Initial precision and accuracy -- To
establish the ability to generate
acceptable precision and accuracy, the
analyst shall perform the following
operations.
8.2.1 For analysis of samples containing low
solids (aqueous samples), extract,
concentrate, and analyze one set of four
one-liter aliquots of reagent water spiked
with the combined OC standard (Section
7.4) according to the procedure in Section
10. Alternatively, sets of four
replicates of the individual calibration
groups (Section 7.3) may be used. For
samples containing high solids, sets of
four 30 gram aliquots of the high solids
reference matrix are used.
8.2.2 Using results of the set of four analyses,
compute the average percent recovery (X)
and the coefficient of variation (Cv) of
percent recovery (s) for each compound.
8.2.3 For each compound, compare s and X with
the corresponding limits for initial
precision and accuracy in Tables 7-9.
For coeluting compounds, use the coeluted
compound with the least restrictive
specification (largest Cv and widest
range). If s and X for all compounds meet
the acceptance criteria, system
performance is acceptable and analysis of
blanks and samples may begin. If,
however, any individual s exceeds the
precision limit or any individual X falls
outside the range for accuracy, system
performance is unacceptable for that
compound. In this case, correct the
problem and repeat the test.
8.3 The laboratory shall spike all samples
with at least one surrogate compound to
assess method performance on the sample
matrix.
8.3.1 Analyze each sample according to the
method beginning in Section 10.
8.3.2 Compute the percent recovery (P) of the
surrogate compound(s).
8.3.3 The recovery of the surrogate compound
shall be within the limits of 40 to 120
percent. If the recovery of any surrogate
falls outside of these limits, method
performance is unacceptable for that
sample, and the sample is complex. Water
samples are diluted, and smaller amounts
of soils, sludges, and sediments are
reanalyzed per Section 17.
8.4 Method accuracy and precision -- The
laboratory shall spike (matrix spike) at
least ten percent of the samples from a
given site type (e.g., influent to
treatment, treated effluent, produced
water, river sediment) in duplicate
(MS/MSD). If only one sample from a given
site type is analyzed, two aliquots of
that sample shall be spiked.
8.4.1 The concentration of the analytes spiked
into the MS/MSD shall be determined as
follows.
8.4.1.1 If, as in compliance monitoring, the
concentration of a specific analyte in the
sample is being checked against a
regulatory concentration limit, the
spiking level shall be at that limit or at
one to five times higher than the
background concentration determined in
Section 8.4.2, whichever concentration is
larger.
8.4.1.2 If the concentration of an analyte in the
sample is not being checked against a
limit specific to that analyte, the matrix
spike shall be at the concentration of the
combined QC standard (Section 7.4) or at
one to five times higher than the
background concentration, whichever
concentration is larger.
8.4.1.3 If it is impractical to determine the
background concentration before spiking
(e.g., maximum holding times will be
exceeded), the matrix spike concentration
shall be the regulatory concentration
limit, if any; otherwise, the larger of
either five times the expected background
concentration or at the concentration of
the combined OC standard (Section 7.4).
8.4.2 Analyze one sample aliquot to determine
the background concentration (B) of each
analyte. If necessary, prepare a standard
solution appropriate to produce a level in
the sample one to five times the
background concentration. Spike two
additional sample aliquots with the
10
-------
8.4.3
standard solution and analyze them to
determine the concentrations after spiking
(A) of each analyte. Calculate the
percent recovery (P) of each analyte in
each aliquot:
P = 100 (A - B) / T
where T is the true value of the spike.
Compare the percent recovery for each
analyte with the corresponding OC
acceptance criteria in Tables 7-9. If
any analyte fails the acceptance criteria
for recovery, the sample is complex and
must be diluted and reanalyzed per Section
17.
Determine the precision of the MS/MSD
analyses by comparing the recoveries
calculated in 8.4.2 of each spiked analyte
in both aliquots. Calculate the relative
percent difference (RPD) of the recoveries
(not the concentrations) of each analyte
with MS/MSD aliquots as:
RPD
P P
MS MSP
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of the analytes of interest into samples
may be required to assess the precision
and accuracy of the sampling and sample
transporting techniques.
9 SAMPLE COLLECTION, PRESERVATION, AND
HANDLING
9.1 Collect samples in glass containers
following conventional sampling practices
(Reference 6), except that the bottle
shall not be prerinsed with sample before
collection. Aqueous samples which flow
freely are collected in refrigerated
bottles using automatic sampling
equipment. Solid samples are collected as
grab samples using wide nouth jars.
9.2 Maintain samples at 0 - 4 °C from the time
of collection until extraction. If the
samples will not be extracted within 72
hours of collection, adjust the sample to
a pH of 5.0 to 9.0 using sodium hydroxide
or suIfuric acid solution. Record the
volume of acid or base used. If residual
chlorine is present in aqueous samples,
add 80 mg sodium thiosulfate per liter of
water. EPA Methods 330.4 and 330.5 may be
used to measure residual chlorine
(Reference 7).
9.3 Begin sample extraction within seven days
of collection, and analyze all extracts
within 40 days of extraction.
10 SAMPLE EXTRACTION AND CONCENTRATION
Figure 1 outlines the extraction and
concentration steps. Samples containing
one percent solids or less are extracted
directly using continuous liquid/liquid
extraction techniques (Section 10.2.1).
Samples containing one through 30 percent
solids are diluted to the one percent
level with reagent water (Section 10.2.2)
and extracted using continuous
liquid/liquid extraction techniques.
Samples containing greater than 30 percent
solids are extracted using ultrasonic
techniques (Section 10.2.5). For
determination of the phenoxy-acid
herbicides, a separate sample aliquot is
extracted, derivatized, and cleaned up.
The derivatized extract may be combined
with the organo-chlorine extract for gas
chromatography.
10.1 Determination of percent solids
10.1.1 Weigh 5 - 10 g of sample into a tared
beaker. Record the weight to three
significant figures.
10.1.2 Dry overnight (12 hours minimum) at 110 *5
°C, and cool in a dessicator.
10.1.3 Determine percent solids as follows:
weight of dry sample
10.2.2.2
10.2.2.3
X solids =
weight of wet sample
x 100
10.2 Preparation of samples for extraction
10.2.1 Samples containing one percent solids or
less -- Pesticides and PCB samples are
extracted directly using continuous
liquid/liquid extraction techniques;
herbicides are extracted using separatory
funnel techniques.
10.2.1.1 Shake the samples to ensure thorough
mixing and measure 1.00 ±0.01 liter of
each sample into a separate clean 1.5 -
2.0 liter beaker. Measure a separate one
liter aliquot for each sample to be tested
for the phenoxy-acid herbicides.
10.2.1.2 Spike 0.5 mL of the surrogate spiking
solution (Section 6.12) into the sample
aliquot. For the phenoxy-acid herbicides,
spike 0.5 mL of the herbicide surrogate
spiking solution into the herbicide
aliquot. Proceed to preparation of the OC
aliquots for low solids samples (Section
10.2.3).
10.2.2 Samples containing one to 30 percent
solids -- Samples are diluted to one
percent solids and then extracted.
10.2.2.1 Mix sample thoroughly.
Using the percent solids found in 10.1.3,
determine the weight of sample required to
produce one liter of solution containing
one percent solids as follows:
sample weight
1000 grams
X solids
Place the weight of sample as determined
in 10.2.2.2 in a clean 1.5 - 2.0 liter
beaker. For the phenoxy-acid herbicides,
place a separate aliquot in a clean
beaker. Discard all sticks, rocks, leaves
and other foreign material prior to
weighing.
12
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10.2.2.4 Bring the sample aliquot(s) to 100 - 200
mL volune with reagent water.
10.2.2.5 Spike 0.5 ml of the appropriate surrogate
spiking solution (Section 6.12) into each
sample aliquot.
10.2.2.6 Using a clean metal spatula, break any
solid portions of the sample into small
pieces.
10.2.2.7 Place the 3/4 in. horn on the ultrasonic
probe approx 1/2 in. below the surface of
each sample aliquot and pulse at 50
percent for three minutes at full power.
If necessary, remove the probe from the
solution and break any large pieces using
the metal spatula or a stirring rod and
repeat the sonication. Clean the probe
with methylene chloride:acetone (1:1)
between samples to preclude cross-
contamination.
10.2.2.8
10.2.3
10.2.3.1
Bring the sample volume to 1.0 ±0.1 liter
with reagent water.
Preparation of OC aliquots for samples
containing <30 percent solids.
For each sample or sample lot (to a
maximum of 20) to be extracted at the same
time, place two 1.0 lO.OI liter aliquots
of reagent water in clean 1.5 - 2.0 liter
beakers. For the phenoxy-aeid herbicides,
place two additional one liter aliquots in
clean beakers.
10.2.3.2 To serve as a blank, spike 0.5 ml of the
pesticide surrogate spiking solution
(Section 6.12.1 and 6.12.2) into one
reagent water aliquot, and 0.5 ml of the
herbicide surrogate spiking solution
(Section 6.12.3) into a second reagent
water aliquot.
10.2.3.3 Spike the combined OC standard (Section
7.4) into a reagent water aliquot. For
the herbicides. spike the herbicide
standard into the remaining reagent water
aliquot.
10.2.3.4 If a matrix spike is required, prepare an
aliquot at the concentrations specified in
Section 8.4.
10.2.4 Stir and equilibrate all sample and QC
solutions for 1 - 2 hours. Extract the
samples and QC aliquots per Section 10.3.
10.2.5 Samples containing 30 percent solids or
greater
10.2.5.1 Nix the sample thoroughly
10.2.5.2 Weigh 30 ±0.3 grams into a clean 400 - 500
ml beaker. For the herbicides, weigh an
additional two 30 gram aliquots into clean
beakers. Discard all sticks, rocks,
leaves and other foreign material prior to
weighing.
10.2.5.3 Herbicide acidification Add 50 ml of
reagent water to one of the herbicide
sample aliquots and stir on a stirring
plate for one hour minimum. Using a pH
meter, determine and record the sample pH
while stirring. Slowly add HjSO^ while
stirring and determine and record the
amount of acid required to acidify the
sample to pH <2. Discard this aliquot.
The volune of H.SO^ will be used during
the extraction of the samples in Section
10.4.6.
10.2.5.4 Spike 0.5 ml of the appropriate surrogate
spiking solution (Section 6.12) into the
pesticide and herbicide aliquots.
10.2.5.5 QC aliquots -- For each sample or sample
lot (to a maximum of 20) to be extracted
at the same time, place two 30 ±0.3 gram
aliquots of the high solids reference
matrix in clean 400 - 500 ml beakers. For
the herbicides, place three additional
aliquots in clean beakers and use one of
these to determine the amount of acid
required for acidification per step
10.2.5.3. Discard this aliquot.
10.2.5.6 To serve as a blank, spike 0.5 ml of the
pesticide surrogate spiking solution
(Section 6.12.1 and 6.12.2) into one
aliquot of the high solids reference
matrix, and 0.5 ml of the herbicide
surrogate spiking solution (Section
6.12.3) into a second aliquot of the high
solids reference matrix.
10.2.5.7 Spike the combined QC standard (Section
7.4) into a high solids reference matrix
aliquot. For the herbicides, spike the
herbicide standard into the remaining high
solids reference matrix aliquot. Extract
the high solids samples per Section 10.4.
10.3 Extraction of low solids (aqueous) samples
10.3.1 Continuous extraction of pesticides/PCB's
- Place 100 150 ml methylene chloride
in each continuous extractor and 200 - 300
nL in each distilling flask.
13
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10.3.1.1
10.3.1.2
10.3.1.3
10.3.1.4
10.3.2
Pour the sample(s), blank, and standard
atiquots into the extractors. Rinse the
glass containers with 50 - 100 ml
methylene chloride and add to the
respective extractors. Include all solids
in the extraction process.
Extraction -- Adjust the pH of the waters
in the extractors to 5 - 9 with NaOH or
H-SO, while monitoring with a pH meter.
Begin the extraction by heating the flask
until the methylene chloride is boiling.
When properly adjusted, 1-2 drops of
methylene chloride per second will fall
from the condenser tip into the water.
Test and adjust the pH of the waters
during the first 1-2 hours of
extraction. Extract for 18 - 24 hours.
Remove the distilling flask, estimate and
record the volume of extract (to the
nearest 100 ml), and pour the contents
through a prerinsed drying column
containing 7 to 10 cm of anhydrous sodium
sulfate (acidified sodium sulfate for the
herbicides). Rinse the distilling flask
with 30 - 50 ml of methylene chloride and
pour through the drying column. For
pesticide extracts and for herbicide
extracts to be cleaned up using GPC,
collect the solution in a 500 ml K-D
evaporator flask equipped with a 10 ml
concentrator tube. Seal, label, and
concentrate per Sections 10.5 through
10.7.
Hydrolysis
herbicides
and back-extraction
of
10.3.2.1 Pour the sample and QC atiquots into
separate 1.5 - 2 L separator/ funnels.
Add 250 g NaCl and shake to dissolve.
10.3.2.2 Add 17 ml of 6 N NaOH to each separatory
funnel and shake to mix thoroughly. Check
the pH of the sample and QC aliquots and
adjust to >12 if required. Periodically
shake the aliquots during a 1 - 2 hour
hydrolysis period.
10.3.2.3 Rinse each beaker used for measurement of
the sample and QC aliquots with 60 ml of
nethylene chloride, add to its respective
separator/ funnel, and extract the sample
by shaking the funnel for two minutes with
periodic venting to release excess
pressure. Allow the organic layer to
separate from the water phase for a
minimum of 10 minutes. If the emulsion
interface between layers is more than one
third the volume of the solvent layer, the
analyst must employ mechanical techniques
to complete the phase separation. The
optimum technique depends upon the sample,
but may include stirring, filtration of
the emulsion through glass wool,
centrifugation, or other physical methods.
Discard the methylene chloride phase. If
the emulsion cannot be broken, continuous
liquid/liquid extraction techniques may be
used. Check and adjust the pH of the
sample to >12 with NaOH if required.
10.3.2.4 Add a second 60 ml volume of methylene
chloride to the sample bottle and repeat
the extraction procedure a second time,
combining the extracts in the Erlenmeyer
flask. Perform a third extraction in the
same manner.
10.3.3 Extraction of the herbicides
10.3.3.1 Add 17 ml of 12 N H-SO^ to the sample and
OC aliquots. Seal and shake to mix.
Caution: some samples require
acidification in a hood because of the
potential for generating hydrogen sulfide.
Check and adjust the pH of the sample to
<2 if required.
10.3.3.2 Add 120 ml ethyl ether to the sample and
QC aliquots. Seal and extract per Section
10.3.2. Drain the aqueous phase
completely into the respective beaker used
for measurement of aliquot volume. Drain
the ether phase into 500 ml round-bottom
flask containing approx 10 g of acidified
sodium sulfate making certain that the
amount of water drained into the flask is
minimized. Periodically, shake the round-
bottom flask to mix the ether solution and
the drying agent.
10.3.3.3 Return the aqueous phase to the separator/
funnel, add a 60 ml volume of ether, and
repeat the extraction a second time.
Drain the aqueous phase completely into
the beaker used for measurement of aliquot
volume and the ether phase into the round-
bottom flask.
10.3.3.4 Repeat the extraction a third time,
combining the ether with the other
extracts in the round-bottom flask. Allow
the sodium sulfate to remain in contact
with the ether solution for a minimum of
two hours, periodically shaking the round-
bottom flask to nix the ether and the
14
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drying agent. Concentrate the extract to
5 ml per Sections 10.5 through 10.7.
10.4 Ultrasonic extraction of high solids
aliquots
10.A.1 Add 60 g powdered (not granular) anhydrous
sodium sulfate to the sample and the QC
alfquots. Add 100 ±10 mL acetonitrile to
each of the aliquots (Section 10.2.5) and
nix thoroughly, to produce a free-flowing
mixture.
10.4.2 Place the 3/4 in. horn on the ultrasonic
probe approx 1/2 in. below the surface of
the solvent but above the solids layer and
pulse at 50 percent for three minutes at
full power. If necessary, remove the
probe from the solution and break any
large pieces using a metal spatula or a
stirring rod and repeat the sonication.
Clean the horn with five percent aqueous
sodium bicarbonate immediately after
sonicating any of the herbicide aliquots
to prevent acid damage to the horn.
10.4.3 Decant the pesticide and herbicide
extracts through filter paper into 1000 -
2000 mL separator/ funnels.
10.4.4 Repeat the extraction and filtration steps
(Sections 10.4.2 - 10.4.3) using a second
100 *10 mL of acetonitrile.
10.4.5 Repeat the extraction step (Section
10.4.2) using 100 ±10 crt of methylene
chloride. On this final extraction, swirl
the sample or QC aliquot, pour into its
respective filter paper, and rinse with
methylene chloride. Record the total
extract volume.
10.4.6 For each extract, prepare 1.5-2 liters
of reagent water containing two percent
sodium sulfate. For the pesticide
extracts, adjust the pH of the water to
6.0 - 9.0 with NaOH or H.SO^. For the
herbicide extracts, adjust the pH of the
water to <2.
10.4.7 Back extract each extract three times
sequentially with 500 nL of the aqueous
sodium sulfate solution, returning the
bottom (organic) layer to the separator/
funnel the first two times while
discarding the top (aqueous) layer. On
the final back extraction, filter each
pesticide extract through a prerinsed
drying column containing 7 to 10 cm
anhydrous sodium sulfate into a 500 - 1000
nL graduated cylinder. Filter the
herbicide extracts similarly using
acidified sodium sulfate. Record the
final extract volume.
10.4.8 Filter the extracts through Whatman *41
paper into 500 nL K-D evaporator flasks
equipped with 10 mL concentrator tubes.
Rinse the graduated cylinder or centrifuge
tube with 30 - 50 mL of methylene chloride
and pour through the filter to complete
the transfer. Concentrate the extracts
per Sections 10.5 through 10.7.
10.5 Concentration
10.5.1 Concentrate the extracts in separate 500
mL K-D flasks equipped with 10 mL
concentrator tubes. Add 1 to 2 clean
boiling chips to the flask and attach a
three-ball macro Snyder column. Prewet
the column by adding approx one mL of
methylene chloride through the top. Place
the K-D apparatus in a hot water bath so
that the entire lower rounded surface of
the flask is bathed with steam. Adjust
the vertical position of the apparatus and
the water temperature as required to
complete the concentration in 15 to 20
minutes. At the proper rate of
distillation, the balls of the column will
actively chatter but the chambers will not
flood.
10.5.2 When the liquid has reached an apparent
volume of one mL, remove the K-D apparatus
from the bath and allow the solvent to
drain and cool for at least 10 minutes.
10.5.3 If the extract is to be cleaned up using
GPC, remove the Snyder column and rinse
the flask and its lower joint into the
concentrator tube with 1 - 2 mL of
methylene chloride. A 5 mL syringe is
recommended for this operation. Adjust
the final volume to 10 mL and proceed to
GPC cleanup in Section 11.
10.6 Hexane exchange -- Extracts to be
subjected to Florist I or silica gel
cleanup and extracts that have been
cleaned up are exchanged into hexane.
10.6.1 Remove the Snyder column, add
approximately 50 nL of hexane and a clean
boiling chip, and reattach the Snyder
column. Concentrate the extract as in
Section 10.5 except use hexane to prewet
the column. The- elapsed time of the
concentration should be 5 - 10 minutes.
15
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10.6.2 Remove the Snyder column and rinse the
flask and Its lower joint into the
concentrator tube with 1 2 mL of hexane.
Adjust the final volume of extracts that
have not been cleaned up by GPC to 10 mL
and those that have been cleaned up by GPC
to 5 ML (the difference accounts for the
50 percent loss in the GPC cleanup).
Clean up the extracts using the Florisil,
silica gel, and/or sulfur removal
procedures in Section 11.
10.7 Herbicide extracts -- These extracts are
concentrated to 5 - 10 mL and the
herbicides are derivatized per Section 12.
11 CLEANUP AND SEPARATION
11.1 Cleanup procedures nay not be necessary
for relatively clean samples (treated
effluents, grounduater, drinking water).
If particular circumstances require the
use of a cleanup procedure, the analyst
may use any or all of the procedures below
or any other appropriate procedure.
However, the analyst shall first repeat
the tests in Section 8.2 to demonstrate
that the requirements of Section 8.2 can
be met using the cleanup procedure(s) as
an integral part of the method. Figure 1
outlines the cleanup steps.
11.1.1 Gel permeation chromatography (Section
11.2) removes many high molecular weight
interferents that cause GC column
performance to degrade. It is used for
all soil and sediment extracts and may be
used for water extracts that are expected
to contain high molecular weight organic
compounds (e.g., polymeric materials,
humic acids).
11.1.2 The solid phase extraction cartridge
(Section 11.3) removes polar organic
compounds such as phenols. It is used for
cleanup of organo-chlorine and organo-
phosphate extracts.
11.1.3 The Florisil column (Section 11.4) allows
for selected fractionation of the organo-
chlorine compounds and will also eliminate
polar interferences.
11.1.4 Alumina column cleanup (Section 11.5) may
also be used for cleanup of the organo-
chlorine compounds.
11.1.5 Elemental sulfur, which interferes with
the electron capture gas chromatography of
some of the pesticides and herbicides, is
removed using GPC, mercury, or activated
copper. Sulfur removal (Section 11.6)
from extracts containing organo-chlorine
is required when sulfur is known or
suspected to be present. Mercury and
copper should not be used for sulfur
removal from extracts expected to contain
the organo-phosphorus pesticides because
some of these analytes are also removed
(Reference 8).
11.2 Gel permeation chromatography (GPC)
11.2.1 Column packing
11.2.1.1 Place 70 - 75 g of SX-3 Bio-beads in a 400
- 500 ml beaker.
11.2.1.2 Cover the beads with methylene chloride
and allow to swell overnight (12 hours
minimum).
11.2.1.3 Transfer the swelled beads to the column
and pump solvent through the column, from
bottom to top, at 4.5 - 5.5 mL/min prior
to connecting the column to the detector.
11.2.1.4 After purging the column with solvent for
1-2 hours, adjust the column head
pressure to 7 - 10 psig, and purge for 4 -
5 hours to remove air. Maintain a head
pressure of 7 - 10 psig. Connect the
column to the detector.
11.2.2 Column calibration
11.2.2.1 Load 5 mL of the calibration solution
(Section 6.5) into the sample loop.
11.2.2.2 Inject the calibration solution and record
the signal from the detector. The elution
pattern will be corn oil, bis(2-ethyl
hexyl) phthalate, pentachlorophenol,
perylene, and sulfur.
11.2.2.3 Set the "dump time" to allow >85 percent
removal of the corn oil and >85 percent
collection of the phthalate.
11.2.2.4 Set the "collect time" to the peak minimum
between perylene and sulfur.
11.2.2.5 Verify the calibration with the
calibration solution after every 20
extracts. Calibration is verified if the
recovery of the pentachlorophenol is
greater than 85 percent. If calibration
is not verified, the system shall be
recalibrated using the calibration
16
-------
< 30% SOLIDS
Percent Solids
> 30% SOLIDS
Dilute to 1% Solids
1
ACN and CHgCLg Sonication
CH CL2 Liquid/Liquid
Extraction
Kp Back Extraction
Concentrate
I
Concentrate
To Cleanup To Cleanup
Method 1618 - Extraction and Concentration Steps
Gel Permeation Cleanup
ORGANOPHOSPHORUS
Solid Phase Extraction
ORGANO-CHLORINE
GCFPD
Florisil
Remove Sulfur
GCHSD
Method 1618 - Cleanup and Analysis Steps
FIGURE 1 Method 1618 - Extraction, Cleanup, and Analysis
17
-------
solution, and the previous 20 samples
shall be re-extracted and cleaned up using
the calibrated GPC system.
11.2.3 Extract cleanup - GPC requires that the
column not be over loaded. The column
specified in this method is designed to
handle a maximum of 0.5 gram of high
molecular weight material in a 5 ml
extract. If the extract is known or
expected to contain more than 0.5 gran,
the extract is split Into fractions for
GPC end the fractions are combined after
elution from the column. The solids
content of the extract may be obtained
gravimetricly by evaporating the solvent
from a 50 uL aliquot.
11.2.3.1 Filter the extract or load through the
filter holder to remove particulates.
Load the 5.0 mL extract onto the column.
11.2.3.2 Elute the extract using the calibration
data determined in Section 11.2.2.
Collect the eluate in a clean 400 - 500 ml
beaker.
11.2.3.3 Rinse the sample loading tube thoroughly
with methylene chloride between extracts
to prepare for the next sample.
11.2.3.4 If a particularly dirty extract is
encountered, a 5.0 ml methylene chloride
blank shall be run through the system to
check for carry-over.
11.2.3.5 Concentrate the extracts per Sections 10.5
- 10.7.
11.3 Solid phase extraction (SPE)
11.3.1 Setup
11.3.1.1 Attach the Vac-elute manifold to a water
aspirator or vacuum pump with the trap and
gauge installed between the manifold and
vacuum source.
11.3.1.2 Place the SPE cartridges in the manifold,
turn on the vacuum source, and adjust the
vacuum to 5 - 10 psia.
11.3.2 Cartridge washing -- Pre-elute each
cartridge prior to use sequentially with
10 it portions each of hexane, methanol,
and water using vacuum for 30 seconds
after each eluant. Follow this pre-
elution with 1 mL methylene chloride and
three 10 ml portions of the elution
solvent (6.6.2.2) using vacuum for five
minutes after each eluant. Tap the
cartridge lightly while under vacuum to
dry between eluants. The three portions
of elution solvent may be collected and
used as a blank if desired. Finally,
elute the cartridge with 10 ml each of
methanol and water, using the vacuum for
30 seconds after each eluant.
11.3.3 Cartridge certification -- Each cartridge
lot must be certified to ensure recovery
of the compounds of interest and removal
of 2,4,6-trichlorophenol.
11.3.3.1 To make the test mixture, add the
trichlorophenol solution (Section 6.6.2.1)
to the combined calibration standard
(Section 7.4). Elute the mixture using
the procedure in 11.3.4.
11.3.3.2 Concentrate the eluant to 1.0 ml and
inject 1.0 uL of the concentrated eluant
into the GC using the procedure in Section
13. The recovery of all organo-chlorine
or organo-phosphorus analytes (including
the unresolved GC peaks) shall be within
the ranges for recovery specified in
Tables 7-8, and the peak for
trichlorophenol shall not be detectable;
otherwise the SPE cartridge is not
performing properly and the cartridge lot
shall be rejected.
11.3.4 Extract cleanup
11.3.4.1 After cartridge washing (Section 11.3.2),
release the vacuum and place the rack
containing the 50 ml volumetric flasks
(Section 5.6.2.4) in the vacuum manifold.
Reestablish the vacuum at 5 - 10 psia.
11.3.4.2 Using a pi pet or a one mL syringe,
transfer 1.0 mL of extract to the SPE
cartridge. Apply vacuum for five minutes
to dry the cartridge. Tap gently to aid
in drying.
11.3.4.3 Elute each cartridge into its volumetric
flask sequentially with three 10 mL
portions of the elutions solvent
(6.6.2.2), using vacuum for five minutes
after each portion. Collect the eluants
in the 50 mL volumetric flasks.
11.3.4.4 Release the vacuum and remove the 50 mL
volumetric flasks.
11.3.4.5 Concentrate the eluted extracts to 1.0 mL
using the nitrogen blow-down apparatus.
Adjust the final volume to 5 or 10 mL (per
Section 10.6), depending on whether or not
18
-------
the extract was subjected to GPC cleanup,
and proceed to Section 13 for GC analysis.
11.4 Florisil column
11.4.1 Place a weight of Florisil (nominally 20
B> predetermined by calibration (Section
7.5) in a chromatographic column. Tap the
column to settle the Florisil and add 1 -
2 cm of anhydrous sodium sulfate to the
top.
11.4.2 Add 60 nL of hexane to wet and rinse the
sodium sulfate and Florisil. Just prior
to exposure of the sodium sulfate layer to
the air, (top the elution of the hexane by
closing the stopcock on the
chromatographic column. Discard the
eluate.
11.4.3 Transfer the concentrated extract (Section
10.6.2) onto the column. Complete the
transfer with two 1-mL hexane rinses.
11.4.4 Place a clean 500 ml K-D flask and
concentrator tube under the column. Drain
the column into the flask until the sodium
sulfate layer is nearly exposed. Elute
fraction 1 with 200 mL of six percent
ethyl ether in hexane (v/v) at a rate of
approx 5 ni/min. Remove the K-D flask.
Elute fraction 2 with 200 ml of 15 percent
ethyl ether in hexane (v/v) into a second
K-D flask. Elute fraction 3 with 200 ml
of 50 percent ethyl ether in hexane (v/v).
11.4.5 Concentrate the fractions as in Section
10.6, except use hexane to preuet the
column. Readjust the final volume to 5 or
10 ml as in Section 10.6, depending on
whether the extract was subjected to GPC
cleanup, and analyze by gas chromatography
per the procedure in Section 13.
11.5 Alumina column
11.5.1 Reduce the volume of the extract to 0.5 nL
and bring to 1.0 nL with acetone.
11.5.2 Add 3 g of activity III neutral alumina to
a 10 nL chromatographic column. Tap the
column to settle the alumina.
11.5.3 Transfer the extract to the top of the
column and collect the eluate in a clean
10 nL concentrator tube. Rinse the
extract container with 1 - 2 nL portions
of hexane (to a total volume of 9 mL) and
add to the alumina column. Do not allow
the column to go dry.
11.5.4 Concentrate the extract to 1.0 mL if
sulfur is to be removed, or adjust the
final volume to 5 or 10 mL as in Section
10.6, depending on whether the extract was
subjected to GPC cleanup, and analyze by
gas chromatography per Section 13.
11.6 Sulfur removal -- Elemental sulfur will
usually elute entirely in fraction 1 of
the Florisil column cleanup.
11.6.1 Transfer the concentrated extract into a
clean concentrator tube or Teflon-sealed
vial. Add 1 - 2 drops of mercury or 100
mg of activated copper powder and seal
(Reference 9). If TBA sulfite is used,
add 1 mL of the TBA sulfite reagent and 2
nL of isopropanol.
11.6.2 Agitate the contents of the vial for 1 - 2
hours on a reciprocal shaker. If the
mercury or copper appears shiny, or if
precipitated sodium sulfite crystals from
the TBA sulfite reagent are present, and
if the color remains unchanged, all sulfur
has been removed; if not, repeat the
addition and shaking.
11.6.3 If mercury or copper is used, centrifuge
and filter the extract to remove all
residual mercury or copper. Dispose of
the mercury waste properly. Bring the
final volume to 1.0 mL and analyze by gas
chromatography per the procedure in
Section 13.
11.6.4 If TBA sulfite is used, add 5 mL of
reagent water and shake for 1 - 2 minutes.
Centrifuge and filter the extract to
remove all precipitate. Transfer the
hexane (top) layer to a sample vial and
adjust the final volume to 5 or 10 mL as
in Section 10.6, depending on whether the
extract was subjected to GPC cleanup, and
analyze by gas chromatography per Section
13.
12 ESTERIFICAT10N OF PHENOXY-ACID HERBICIDES
12.1 Concentrate the extract to approximately 5
mL per Section 10.5 and further
concentrate the extract to near dryness
using the nitrogen blowdown apparatus.
Bring the volume to 5 nL with isooctane.
If desired, the extract nay be transferred
to a 10 nL sample vial and stored at -20
to -10 'C.
19
-------
12.2 Esterification -- Observe the safety
precautions regarding diazomethane in
Section 4.
12.2.1 Set up the diazomethane generation
apparatus as given in the instructions in
the Diazald kit.
12.2.2 Transfer one mL of the isooctane solution
(Section 12.1) to a clean vial and add 0.5
L of met Hanoi and 3 ML of ether. For
extracts that have been cleaned up by GPC,
use 2 H to account for the loss.
12.2.3 Add two ML of diazomethane solution and
let the sample stand for 10 minutes with
occasional swirling. The yellow color of
diazomethane should persist throughout
this period. If the yellow color
disappears, add two mL of diazomethane
solution and allow to stand, with
occasional swirling, for another 10
inutes. Colored or complex samples will
require at least 4 mL of diazomethane to
ensure complete reaction of the
herbicides. Continue adding diazomethane
in 2 mL increments until the yellow color
persists for the entire 10 minute period
or until 10 mL of diazomethane solution
has been added.
12.2.4 Rinse the inside wall of the container
with 0.2 - 0.5 mL of diethyl ether and add
10 - 20 mg of silicic acid to react excess
diazomethane. Filter through Whatman #41
paper into a clean sample vial. If the
solution is colored or cloudy, evaporate
to near dryness using the nitrogen
blowdown apparatus, bring to 10 mL with
hexane, and proceed to Section 11.3 for
SPE cleanup. If the solution is clear and
colorless, evaporate to near dryness,
bring to 1.0 mL with hexane and proceed to
Section 13 for GC analysis.
13 GAS CHROMATOGRAPHY
Tables 4 through 6 summarize the
recommended operating conditions for the
gas chromatographs. Included in these
tables are the retention times and
estimated detection limits that can be
achieved under these conditions. Examples
of the separations achieved by the primary
and confirmatory columns are shown in
Figures 2 through 6.
13.1 Calibrate the system as described in
Section 7.
13.2 Combining pesticide and herbicide extracts
13.2.1 Pesticide extracts cleaned up by solid
phase extraction -- Combine the 1.0 ml
final organo-chlorine pesticide extract
(Section 11.3.4.5 or 11.5.4) with the 1.0
ml final herbicide extract (Section
11.3.4.5 or 11.5.4 if the herbicide
extract required cleanup; Section 12.2.4
if it did not).
13.2.2 Pesticide extracts cleaned up by Florisil
-- Combine 1.0 ml of the 5.0 ml or 10.0 ml
pesticide extract (Section 11.4.5) with
the 1.0 ml final herbicide extract
(Section 11.3.4.5 or 11.5.4 if the
herbicide extract required cleanup;
Section 12.2.4 if it did not).
13.3 Set the injection volume on the
autosampler to inject 1.0 uL of all
standards and extracts of blanks and
samples.
13.4 Set the data system or GC control to start
the temperature program upon sample
injection, and begin data collection after
the solvent peak elutes. Set the data
system to stop data collection after the
last analyte is expected to elute and to
return the column to the initial
temperature.
14 SYSTEM AND LABORATORY PERFORMANCE
14.1 At the beginning of each eight hour shift
during which analyses are performed, GC
system performance and calibration are
verified for all pollutants and surrogates
on all column/detector systems. For these
tests, analysis of the combined OC
standard (Section 7.4) shall be used to
verify all performance criteria.
Adjustment and/or recalibration (per
Section 7) shall be performed until all
performance criteria are met. Only after
all performance criteria are met may
samples, blanks, and precision and
recovery standards be analyzed.
14.2 Retention times -- The absolute retention
times of the peak maxima shall be within
±10 seconds of the retention times in the
initial calibration (Section 7.4.1).
14.3 GC resolution -- Resolution is acceptable
if the valley height between two peaks (as
measured from the baseline) is less than
10 percent of the taller of the two peaks.
20
-------
56 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25
FIGURE 2 Organochlorine Mix A [(A) DDB-608 and (B) DB-1701].
21
-------
(B)
o
» i
(A)
56 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25
FIGURE 3 Organochlorine Mix B [(A) DB-608 and (B) DB-1701].
22
-------
(B)-j
(A)
iupru[iHi|mT|inipmpTn|Miqun|uupiu|Hnpmfnupm[nn|iiii|iiu^
6 7 6 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 26 30 31 32 33 3* 35 36 37 38 39 40 41 42 43 44 45 46 47 48 *9 50 51 52 53 54 55 56
FIGURE 4 Organophosphate Mix A [(A) DB-1 and (B) DB-1701).
23
-------
(B)
K.JL
<
|
s
£
m
i
I AJ
(A)
I I
o
uu
LJ
.-A...
mlHUlM"!""!""!""!""!""!""!""!""!""!""!""!""!"1
6 7 B 9 10 11 12 13 14 15 16 17 18 19 20
II 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 36 39 40 41 42 43 44 45 46 47 46 49 50 51 52 53 54 55 56
FIGURE 5 Organophosphate Mix B [(A) DB-1 and (B) DB-1701].
24
-------
(B)
FIGURE 6 Phenoxy-acid Herbicides [(A) DB-608 and (B) DB-1701]
25
-------
14.3.1 Organo-halide compounds
14.3.1.1 Primary col inn (DB-608) -- DDT and endrin
aldehyde.
14.3.1.2 Confirmatory column (DB-1701) -- Alpha and
gamma chlordane.
14.3.2 Organo-phosphorus compounds
14.3.2.1 Primary column (DB-1) - Ma lath ion and
ethyl parathion.
14.3.2.2 Confirmatory column (DB-1701) -- Terbufos
and diazinon.
14.4 Decomposition of DDT and endrin
14.4.1 Analyze a total of 2 ng DDT and 1 ng
endrin on each organo-chlorine column
using the analytical conditions specified
in Table 4.
14.4.2 Measure the total area of all peaks in the
chromatogram.
14.4.3 The area of peaks other than the sum of
the areas of the DDT and endrin peaks
shall be less than 20 percent the sum of
the areas of these two peaks. If the area
is greater than this sum, the system is
not performing acceptably for DDT and
endrin. In this case, the GC system that
failed shall be repaired and the
performance tests (Sections 14.1 - 14.4)
shall be repeated until the specification
is met. Note: DDT and endrin
decomposition are usually caused by
accumulations of particulates in the
injector and in the front end of the
column. Cleaning and silanizing the
injection port liner, and breaking off a
short Section of the front end of the
column will usually eliminate the
decomposition problem.
14.5 Calibration verification - Calibration is
verified for the combined OC standard
only.
14.5.1 Inject the combined OC standard (Section
7.4)
14.5.2 Compute the percent recovery of each
compound or coeluting compounds, based on
the calibration data (Section 7.4).
14.5.3 For each compound or coeluted compounds,
compare this calibration verification
recovery with the corresponding limits for
ongoing accuracy in Tables 7-9. For
coeluting compounds, use the coeluted
compound with the least restrictive
specification (the widest range). If the
recoveries for all compounds meet the
acceptance criteria, system performance is
acceptable and analysis of blanks and
samples may begin. If, however, any
recovery falls outside the calibration
verification range, system performance is
unacceptable for that compound. In this
case, correct the problem and repeat the
test, or recalibrate (Section 7). If
verification requirements are met, the
calibration is assumed to be valid for the
multicomponent analytes (PCB's and
toxaphene).
14.6 Ongoing precision and recovery
14.6.1
14.6.2
14.6.3
14.6.4
Analyze the extract of the precision and
recovery standard extracted with each
sample lot (Sections 10.2.3.3 and
10.2.5.7).
Compute the percent recovery
analyte and coeluting compounds.
of each
For each compound or coeluted compounds,
compare the percent recovery with the
limits for ongoing recovery in Tables 7 -
9. For coeluted compounds, use the
coeluted compound with the least
restrictive specification (widest range).
If all analytes pass, the extraction,
concentration, and cleanup processes are
in control and analysis of blanks and
samples may proceed. If, however, any of
the analytes fail, these processes are not
in control. In this event, correct the
problem, re-extract the sample lot, and
repeat the ongoing precision and recovery
test.
Add results which pass the specifications
in Section 14.6.3 to initial and previous
ongoing data. Update OC charts to form a
graphic representation of continued
laboratory performance. Develop a
statement of laboratory data quality for
each analyte by calculating the average
percent recovery (R) and the standard
deviation of percent recovery sr. Express
the accuracy as a recovery interval from R
- 2sr to R * 2sr. For example, if R <= 95X
and sr = 5X, the accuracy is 85 - 105X.
26
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15 QUALITATIVE DETERMINATION
16 QUANTITATIVE DETERMINATION
15.1 Qualitative determination is accomplished
by comparison of data from analysis of a
sample or blank with data from analysis of
the shift standard (Section U.2), and
with data stored in the retention time and
calibration libraries (Section 7.3.3 and
7.3.4.1). Identification is confirmed
when retention time and amounts agree per
the criteria below.
15.2 For each compound on each column/detector
system, establish a retention time window
±20 seconds on either side of the
retention time in the calibration data
(Section 7.3.3). For compounds that have
a retention time curve (Section 7.3.3.2),
establish this window as the minimum -20
seconds and maxinun +20 seconds. For the
multi-component analytes, use the
retention times of the five largest peaks
in the chromatogram from the calibration
data (Section 7.3.3).
15.2.1 Compounds not requiring a retention time
calibration curve -- If a peak from the
analysis of a sample or blank is within a
window (as defined in Section 15.2) on the
primary column/detector system, it is
considered tentatively identified. A
tentatively identified compound is
confirmed when (1) the retention time for
the compound on the confirmatory
column/detector system is within the
retention time window on that system, and
(2) the computed amounts (Section 16) on
each system (primary and confirmatory)
agree within a factor of three.
15.2.2 Compounds requiring a retention time
calibration curve -- If a peak from the
analysis of a sample or blank is within a
window (as defined in Section 15.2) on the
primary column/detector system, it is
considered tentatively identified. A
tentatively identified compound is
confirmed when (1) the retention times on
both systems (primary and confirmatory)
are within ±30 seconds of the retention
times for the computed amounts (Section
16), as determined by the retention time
calibration curve (Section 7.3.3.2), and
(2) the computed amounts (Section 16) on
each system (primary and confirmatory)
agree within a factor of three.
16.1
16.2
16.3
16.4
16.5
Using the GC data system, compute the
concentration of the analyte detected in
the extract (in ug/mL) using the
calibration factor or calibration curve
(Section 7.3.3.2).
Liquid samples -- Compute the
concentration in the sample using the
following equation:
Cs
where,
Cs «
10 =
Cex
Vs =
10 (Cex)
(Vs)
the concentration in the sample
in ug/L.
extract total volume in ml.
concentration in the extract in
ug/mL.
volume of sample extracted in
liters.
Solid samples -- Compute the concentration
in the solid phase of the sample using the
following equation:
Cs « -
where,
Cs
10
Cex
1000
Us
X solids
10 (Cex)
1000 (Us) (X solids)
concentration in the sample
in ug/kg.
extract total volume in ml.
concentration in the extract
in ug/mL.
used to convert grams to
kilograms.
sample weight in grams.
percent solids as determined
in Section 10.1.3.
If the concentration of any analyte
exceeds the calibration range of the
system, the extract is diluted by a factor
of 10, and a one uL aliquot of the diluted
extract is analyzed.
Two or more PCB's in a given sample are
quantitated and reported as total PCB.
16.6 Report results for all pollutants found in
all standards, blanks, and samples to
three significant figures. Results for
samples that have been diluted are
reported at the least dilute level at
which the concentration is in the
calibration range.
27
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17 ANALYSIS OF COMPLEX SAMPLES
17.1 Sane samples nay contain high levels
(>1000 ng/L) of the compounds of interest,
interfering compounds, and/or polymeric
Materials. Some samples may not
concentrate to 10 »L (Section 10.6);
others nay overload the GC column and/or
detector.
17.2 The analyst shall attempt to clean up all
camples using GPC (Section 11.2), and the
SPE cartridge (Section 11.3), and samples
for the organo-halide compounds by
florisil (Section 11.4) or alumina (11.5),
and sulfur removal (Section 11.6). If
these techniques do not remove the
interfering compounds, the extract is
diluted by a factor of 10 and reanalyzed
(Section 16.4).
17.3 Recovery of surrogates -- In most samples,
surrogate recoveries will be similar to
those from reagent water or from the high
solids reference matrix. If the surrogate
recovery is outside the range specified in
Section 8.3, the sample shall be
reextracted and reanalyzed. If the
surrogate recovery is still outside this
range, the sample is diluted by a factor
of 10 and reanalyzed (Section 16.4).
17.4 Recovery of matrix spikes -- In most
samples, matrix spike recoveries will be
similar to those from reagent water or
from the high solids reference matrix. If
the matrix spike recovery is outside the
range specified in Tables 7-9, the
sample shall be diluted by a factor of 10,
respiked, and reanalyzed. If the matrix
spike recovery is still outside the range,
the method does not apply to the sample
being analyzed and the result may not be
reported for regulatory compliance
purposes.
18 METHOD PERFORMANCE
18.1
REFERENCES
1
Development of this method is detailed in
Reference 10.
Working with Carcinogens," DHEU, PHS,
CDC, NIOSH, Publication 77-206, (August
1977).
OSHA Safety and Health Standards, General
Industry* OSHA 2206, 29 CFR 1910 (January
1976).
10
Safety in Academic Chemistry
Laboratories," ACS Committee on Chemical
Safety (1979).
Mills, P. A., "Variation of Florisil
Activity: Simple Method for Measuring
Adsorbent Capacity and Its Use in
Standardizing Florisil Columns," J. Assoc.
Off. Analytical Chemists, 51, 29 (1968).
"Handbook of Analytical Quality Control in
Water and Wastewater Laboratories," USEPA,
EMSL, Cincinnati, OH 45268, EPA-600/4-79-
019 (March 1979).
Standard Practice for Sampling Water,"
ASTM Annual Book of Standards, ASTM,
Philadelphia, PA, 76 (1980).
Methods 330.4 and 330.5 for Total
Residual Chlorine," USEPA, EMSL,
Cincinnati, OH 45268, EPA 600/4-70-020
(March 1979).
"Method Development and Validation, EPA
Method 1618, Cleanup Procedures", Colorado
State University, Department of
Environmental Health, Colorado Pesticide
Center, November 1988 and January 1989.
Goerlitz, D.F., and Law, L.M. "Bulletin
for Environmental Contamination and
Toxicology," 6, 9 (1971).
"Consolidated GC Method for the
Determination of ITD/RCRA Pesticides using
Selective GC Detectors," Report Reference
32145-01, Document R70, S-CUBED, A
Division of Maxwell Laboratories, Inc, PO
Box 1620, La Jolla, CA, 92038-1620
(September 1986).
28
-------
Table 1
ORGANO-HALIDE PESTICIDES DETERMINED BY WIDE BORE,
FUSED SILICA CAPILLARY COLUMN GAS CHROMATOGRAPHY
WITH HALIDE SPECIFIC DETECTOR
Table 2
ORGANO-PHOSPHORUS PESTICIDES DETERMINED BY WIDE BORE,
FUSED SILICA CAPILLARY COLUMN GAS CHROMATOGRAPHY
WITH FLAME PHOTOMETRIC DETECTOR
EGD
No.
089
102
103
105
104
434
433
441
091
431
094
093
092
432
478
090
095
096
097
098
099
435
100
101
437
439
430
438
436
112
108
109
106
110
107
111
440
113
442
Compound
Aldrin
alpha-BHC
beta-BHC
delta-BHC
gannia-BHC (Lindane)
Captafol
Captan
Carbophenothion
Chlordane
Chlorobenzilate
4,4<-DDD
4,4' -DDE
4, 4' -DDT
Dial late
Dichlone
Dieldrin
Endosulfan I
Endosulfan II
Endosulfan sulfate
Endrin
Endrin aldehyde
Endrin ketone
Heptachlor
Heptachlor epoxide
Isodrin
Kepone
Methoxychlor
Mi rex
Nitrofen (TOO
PCB-1016
PCB-1221
PCB-1232
PCB-1242
PCB-1248
PCB -1254
PCB-1260
PCNB (pentachloronitrobenzene)
Toxaphene
Trif luralin
CAS Registry
309-00-2
319-84-6
319-85-7
319-86-8
58-89-9
2425-06-1
133-06-2
786-19-6
57-74-9
510-15-6
72-54-8
72-55-9
50-29-3
2303-16-4
117-80-6
60-57-1
959-98-8
33213-65-9
1031-07-8
72-20-8
7421-93-4
53494-70-5
76-44-8
1024-57-3
465-73-6
143-50-0
72-43-5
2385-85-5
1836-75-5
12674-11-2
11104-28-2
11141-16-5
53469-21-9
12672-29-6
11097-69-1
11096-82-5
82-68-8
8001-35-2
1582-09-8
EGD
No.
468
453
461
469
443
479
471
460
450
455
449
452
458
467
463
446
454
447
464
474
475
456
444
470
459
448
457
465
473
477
476
472
466
445
451
462
NON
Compound
Azinphos ethyl
Azinphos methyl
Chlorfevinphos
Chlorpyrifos
Coumaphos
Crotoxyphos
Demeton
Diazinon
Dichlorvos
Dicrotophos
Dimethoate
Dioxathion
Disulfoton
EPN
Ethion
Famphur
Fensulfothion
Fenth i on
Hexamethylphosphoramide
Leptophos
Ma lath ion
Methyl pa rath ion
Mevinphos
Mooocrotophos
Naled
Parathion
Phorate
Phosmet
Phosphamidon
Sulfotepp
TEPP
Terbufos
Tetrachlorvinphos
Trichlorofon
Tricresylphosphate
Trimethylphosphate
-ITD ORGANO- PHOSPHATE COMPOUNDS
CAS Registry
2642-71-9
86-50-0
470-90-6
2921-88-2
56-72-4
7700-17-6
8065-48-3
333-41-5
62-73-7
141-66-2
60-51-5
78-34-2
298-04-4
2104-64-5
563-12-2
52-85-7
115-90-2
55-38-9
680-31-9
21609-90-5
121-75-5
298-00-0
7786-34-7
6923-22-4
300-76-5
56-38-2
298-02-2
732-11-6
13171-21-6
3689-24-5
107-40-3
13071-79-9
961-11-5
42-68-6
78-30-8
512-56-1
THAT CAN BE
ANALYZED BY THIS METHOD
NON-ITD ORGANO-HALIDE COMPOUNDS THAT CAN BE
ANALYZED BY THIS METHOD
Compound
Chloroneb
Chloropropylate
DBCP
Dicofol
Etridiazole
Perthane (Ethylan)
Propachlor
Strobane
CAS Registry
2675-77-6
5836-10-2
96-12-8
115-32-2
2593-15-9
72-56-0
1918-16-7
8001-50-1
Comxxjnd
Bolster
Dichlorofenthion
Ethoprop
Merphos
Methyl Chlorpyrifos
Methyl trithion
Rormel
Su I prof os
Tokuthion
Trichloronate
CAS Registry
35400-43-2
97-17-6
13194-48-4
150-50-5
5598-
953-
299-84-3
35400-43-2
34643-46-4
327-98-0
13-0
17-3
29
-------
Table 3
PHENOXYACID HERBICIDES DETERMINED BY WIDE BORE,
FUSED SILICA CAPILLARY COLUMN GAS CHROMATOGRAPHY
WITH HALIDE SPECIFIC DETECTOR
EGD
NO.
481
480
482
483
Compound
2,4-D
Dinoseb
2,4,5-T
2,4,5-TP
CAS Registry
94-75-7
88-85-7
93-76-5
93-72-1
NON-ITD PHENOXYACID HERBICIDES THAT CAN BE
ANALYZED BY THIS METHOD
Compound CAS Registry
Dalapon 75-99-0
2,4-DB (Butoxon) 94-82-6
Dicamba 1918-00-9
Dichlorprop 120-36-5
MCPA 94-74-6
MCPP 93-65-2
30
-------
Table 4
GAS CHROMATOGRAPHY OF ORGANO-HALIDE PESTICIDES
EGD
No.
442
432
102
440
104
103
100
478
105
089
437
101
091
095
093
090
433
431
098
436
439
094
096
092
441
099
097
434
438
Retention Time (1)
Compound
Trif luralin
Dialtate-A
Diallate-B
alpha-BHC
PCNB
gamma-BHC (Lindane)
beta-BHC
Heptachlor
Dichlone
delta-BHC
Aldrin
Isodrin
Heptachlor epoxide
ganma-Chlordane
alpha-Chlordane
Endosulfan I
4,4'-DDE
Dieldrin
Captan
Chlorobenzi late
Endrin
Nitrofen (TDK)
Kepone
4.4'-DOO
Endosulfan II
4,4'-DOT
Carbophenothion
Endrin aldehyde
Endosulfan sulfate
Captafol
M i rex
OB-608
5
7
7
8
9
9
9
10
10
11
11
13
13
14
15
15
16
16
16
17
17
17
17
18
18
19
19
19
20
22
22
.16
.15
.42
.14
.03
.52
.86
.66
.80
.20
.84
.47
.97
.63
.24
.25
.34
.41
.83
.58
.80
.86
.92
.43
.45
.48
.65
.72
.21
.51
.75
DB-1701
8
8
8
9
9
10
13
11
14
12
13
15
16
16
15
16
17
17
18
18
19
25
19
19
20
20
21
22
23
21
.58
.05
.58
.45
.91
.84
.58
.56
(3)
.39
.50
.93
.03
.20
.48
.96
.76
.32
.32
.97
.06
.14
.03
.56
.72
.10
.21
.18
.36
.11
.82
HDL (2)
(ng/L)
50 est
45
32
6
6
11
7
5
(4)
5
8
13
12
9
8
11
10
6
(4)
25
4
13
(4)
5
8
12
50
11
7
(4)
4
EGD
No.
430
435
106
109
112
108
110
107
111
113
(1)
Retention Time (1)
Compound
Methoxychlor
Endrin ketone
PCS- 1242
PCS- 1232
PCB-1016
PCB-1221
PCS- 1248
PCB-1254
PCB-1260
Toxaphene
Columns: 30 m x
micron; DB-1701: 1.
DB-608
22.80
23.00
15.44
15.73
16.94
17.28
19.17
16.60
17.37
18.11
19.46
19.69
0.53 mm i
0 micron.
DB-1701
22.34
23.71
14.64
15.36
16.53
18.70
19.92
16.60
17.52
17.92
18.73
19.00
MDL (2)
(ng/L)
30
8
140
910
.d.; DB-608: 0.83
Conditions: 150 °C for 0.5 min, 150 -
°C per minute, 270 °C until endrin
elutes.
270 a 5
ketone
Carrier gas flow rate: approximately 7 mL/min.
(2)
(3)
(4)
40 CFR Part 136,
Detection limits
estimated to be 30
Appendix
for soils
- 100 times
Does not elute from DB-1701
tested.
Not recovered from
B (49 FR 43234).
(in ng/kg) are
this level.
column at level
water at levels tested.
31
-------
Table 5
GAS CHROMATOGRAPHY OF ORGANO-PHOSPHORUS PESTICIDES
EGO
No.
450
444
445
471
459
455
470
477
457
449
452
472
473
458
460
456
475
447
448
469
Retention Time (1)
Compound
Dichlorvos
Mevinphos
Trichlorofon
Demeton-A
Ethoprop
Naled
Dicrotophos
Honocrotophos
Sulfotepp
Phorate
Dimethoate
Demeton-B
Dioxathion
Terbufos
Phosphamidon-E
Disulfoton
Diazinon
Tributyl phosphate
(surr)
Phosphamidon-Z
Methyl parathion
0 i ch I orof ent h i on
Methyl chlorpyrifos
Ronnel
Malathion
Fenthion
Parathion (ethyl)
Chlorpyrifos
Trichloronate
DB-608
6
11
12
17
18
18
19
19
20
20
20
21
22
22
23
23
24
24
25
25
26
26
27
28
.56
.85
.69
.70
.49
.92
.33
.62
.04
.12
.59
.40
.24
.97
.70
.89
.03
.50
.88
.98
.11
.29
.33
.87
29.14
29
29
30
.29
.48
.44
DB-1701
9
16
18
20
21
23
26
29
23
23
29
25
26
24
29
27
26
17
32
32
28
29
30
33
32
34
32
32
.22
.20
.85
.57
.43
.00
.30
.24
.68
.08
.29
.52
.70
.55
.89
.01
.10
.20
.62
.12
.66
.53
.09
.49
.16
.61
.15
.12
MDL (2)
(ng/L)
4
74
150 (3)
19
7
18
81
85
6
10
27
21
121
26
28
32
38
-
116
18
6
13
11
11
22
10
4
14
EGD
No.
461
479
466
454
463
446
465
467
453
474
468
443
(1)
Retention
Compound
Chlorfevinphos
Crotoxyphos
Tokuthion
Tetrachlorvinphos
Merphos-B
Fensulfothion
Methyl trithion
Ethion
Sulprofos (Bolstar)
Famphur
Phosmet
EPN
Azinphos methyl
Leptophos
Azinphos ethyl
Triphenyl phosphate
(surr)
Coumaphos
Columns: 30 m x 0.53
DB-1701: 1.0 micron.
Time (1) MDL
(2)
DB-608 DB-1701 (ng/L)
32.05
32.65
33.30
33.40
35.16
36.58
36.62
37.61
38.10
38.24
41.24
41.94
43.33
44.32
45.55
47.68
48.02
mm i.d.;
36.08
37.58
37.17
37.85
37.37
43.86
40.52
41.67
41.74
46.37
48.22
47.52
50.26
47.36
51.88
40.43
56.44
2
81
2
12
18
104
10
13
6
27
14
9
9
14
22
-
24
DB-1: 1.5 micron;
Conditions: 110 °C for 0.5 min, 110 - 250
(2)
(3)
°C per minute, 250 °C
Carrier gas flow rate:
a 3
until coumaphos e lutes.
approximately 7 mL/min.
40 CFR Part 136, Appendix B (49
Estimated: Detection limits
ng/kg) are estimated
level.
to be 30
FR 43234).
for soils
- 100 times
(in
this
32
-------
Table 6
GAS CHROMATOGRAPHY OF PHENOXY-ACID
HERBICIDES
EGO
No.
481
480
482
483
Compound
2,4-D
D i noseb
2,4, 5-T
2,4,5-TP (SHvex)
Dalapon
2,4-DB (Butoxon)
D i camba
Dichlorprop
MCPA
MCPP
Retention
DB-608
5.85
7.92
6.97
8.74
4.39
5.15
4.74
4.24
Time (1)
DB-1701
6.05
8.20
7.37
9.02
4.39
5.46
4.94
4.55
HDL (2)
(ng/L)
100
100 est
50
40
1000 est
50
110
40
90
56
(1) Columns: Same as for the organo-chlorine
pesticides. See Table 4.
Conditions: 175 °C for 0.5 min, 175 - 270 3 5
°C per minute.
Carrier gas flow rate: approximately 7 mL/min.
(2) 40 CFR Part 136, Appendix B (49 FR 43234).
Detection limits for soils (in ng/kg) are
estimated to be 30 - 100 times this level.
33
-------
Table 7
ACCEPTANCE CRITERIA FOR PERFORMANCE TESTS FOR ORGANO-HALIDE COMPOUNDS
Acceptance Criteria
EGD
No.(1) Compound
089
102
103
105
104
434
433
441
091
431
094
093
092
432
478
090
095
096
097
098
099
435
100
101
437
439
430
438
436
112
108
109
106
110
107
111
440
113
442
Aldrin
alpha-BHC
beta-BHC
delta-BHC
gamma-BHC (Lindane)
Captafol (2)
Captan (2)
Carbophenoth i on
Chlordane-alpha
Chlordane-gamma
Chlorobenzilate
4,4'-DDD
4,4'-DDE
4,4'-DDT
Diallate
Oichlone (2)
Dieldrin
Endosulfan I
Endosulfan II
Endosulfan sulfate
Endrin
Endrin aldehyde
Endrin ketone
Heptachlor
Heptachlor epoxide
Isodrin
Kepone (2)
Methoxychlor
Mi rex
Nitrofen (TDK)
PCB-1016
PCB-1221
PCB-1232
PCB-1242
PCB-1248
PCB-1254
PCB-1260
PCNB
Toxaphene
Trif luralin
Spike
level
(ng/L)
100
100 '
100
100
100
1000
100
100
500
100
200
200
250
100
200
200
100
100
200
100
100
100
100
200
100
200
1000
100
5000
200
Initial
precision
and accuracy
Sec 8.2 (X)
s
12
10
10
24
10
10
10
13
19
12
13
19
16
11
14
19
17
13
13
25
12
13
15
19
23
22
20
11
20
12
X
82 -
57 -
66 -
60 -
66 -
63 -
79 -
32 -
58 -
69 -
66 -
86 -
44 -
79 -
66 -
41 -
78 -
50 -
17 -
0 -
36 -
78 -
63 -
69 -
50 -
25 -
15 -
82 -
49 -
82 -
32 -
Calibration
verification
Sec 14.5
(ug/mL)
108
135
130
122
112
141
122
140
118
117
114
112
120
110
140
133
142
130
149
149
126
104
117
113
136
155
139
112
129
112
148
79 -
69 -
85 -
79 -
75 -
70 -
49 -
79 -
73 -
79 -
54 -
77 -
81 -
77 -
70 -
48 -
78 -
76 -
70 -
5 -
86 -
68 -
80 -
79 -
71 -
47 -
47 -
78 -
59 -
79 -
78 -
68 -
47 -
113
108
102
103
119
107
114
102
102
113
129
109
121
118
124
115
119
119
109
117
117
135
114
117
126
134
128
114
142
126
101
134
134
Recovery
Sec 8.4
Ongoing
accuracy
Sec 14.6
R (%)
76 -
38 -
50 -
45 -
55 -
43 -
69 -
4 -
43 -
57 -
54 -
79 -
24 -
48 -
18 -
62 -
31 -
0 -
0 -
14 -
71 -
49 -
45 -
28 -
0 -
0 -
75 -
29 -
76 -
3 -
114
154
146
136
123
161
133
169
133
129
126
119
139
158
156
158
149
182
190
148
111
131
127
158
188
170
119
149
122
177
(1) Reference numbers beginning with 0 or 1 indicate a pollutant quantified by the internal standard method.
(2) Not recovered.
-------
Table 8
ACCEPTANCE CRITERIA FOR PERFORMANCE TESTS FOR ORGANO-PHOSPHORUS COMPOUNDS
Acceptance Criteria
EGO
No.
468
453
461
469
443
479
471
460
450
455
449
452
458
467
463
446
454
447
464
474
475
456
444
470
459
448
457
465
473
477
476
472
466
445
451
462
Compound
Azinphos ethyl
Azinphos methyl
Chlorfevinphos
Chlorpyrifos
Coumaphos
Crotoxyphos
Demeton-S
Diazinon
Dichlorvos
Dicrotophos (1)
Dimethoate
Dioxathion
Disulfoton
EPN
Ethion
Famphur
Fensulfothion
Fenthion
Hexamethylphosphoramide (1)
Leptophos
Malathion
Methyl parathion
Mevinphos
Monocrotophos (1)
Naled
Parathion
Phorate
Phosmet
Phosphamidon-Z
Sulfotepp
TEPP (1)
Terbufos
Tetrachlorvinphos
Trichlorofon (1)
Tricresylphosphate
Trimethylphosphate (1)
Diehlorofenthion
Ethoprop
Merphos-B
Methyl chlorpyrifos
Methyl trithion
Rome I
Sulprofos (Bolster)
Tokuthion
Trichloronate
Spike
level
59 -
37
37
48 -
72
6 -
16 -
60
39
78 -
22 -
49
33 -
62
47
76
0 -
61
70
80
66 -
61
7 -
19 -
0
61
43
25 -
0 -
58 -
70
47
32 -
70
74 -
70 -
65 -
73
59
83
0 -
71 -
70
65
77
129
127
151
125
110
138
118
120
119
122
100
111
111
136
149
106
141
109
130
110
118
123
107
206
176
121
109
138
100
132
130
123
126
130
114
130
125
109
111
113
166
119
100
113
107
(1) Not recovered.
35
-------
Table 9
ACCEPTANCE CRITERIA FOR PERFORMANCE TESTS FOR PHENOXY-ACID COMPOUNDS
Acceptance Criteria
EGO
No. Compound
Spi ke
level
(ng/L)
Initial
precision
and accuracy
Sec 8.2 (X)
s X
Calibration
verification
Sec 14.5
(ug/mL)
Recovery
Sec 8.4
Ongoing
accuracy
Sec 14.6
R (%)
481 2,4-D
480 Dinoseb
482 2,4,5-T
483 2,4,5-TP (Silvex)
Dalapon
2,4-DB (Butoxon)
Dicamba
Dichlorprop
MCPA
MCPP
200
100
100
100
200
100
200
400
16
17
14
16
18
14
14
14
41 107
30 - 132
36 120
22 118
37 - 145
49 - 133
46 - 130
65 - 149
70 130
70 - 130
70 130
70 130
70 - 130
70 - 130
70 - 130
70 - 130
23 131
5 - 158
15 - 141
0 - 142
10 172
28 154
25 151
42 - 170
36
------- |