ASTM D5241-92(2024)
(Practice)Standard Practice for Micro-Extraction of Water for Analysis of Volatile and Semi-Volatile Organic Compounds in Water
Standard Practice for Micro-Extraction of Water for Analysis of Volatile and Semi-Volatile Organic Compounds in Water
SIGNIFICANCE AND USE
4.1 This practice provides a general procedure for the solvent extraction of volatile and semi-volatile organic compounds from a water matrix. Solvent extraction is used as the initial step in the solvent extraction of organic constituents for the purpose of quantifying extractable organic compounds.
4.2 Typical detection limits that can be achieved using micro-extraction techniques with gas chromatography (GC) with flame ionization detector (FID), electron capture detector (ECD), or with a mass spectrometer (GC/MS) range from milligrams per litre (mg/L) to nanograms per litre (ng/L). The detection limit, linear concentration range, and sensitivity of the test method for a specific organic compound will depend upon the sample clean-up, injection volume, solvent to sample ratio, solvent concentration methods used, and the determinative technique employed.
4.3 Micro-extraction has the advantage of speed, simple extraction devices, and the use of small amounts of sample and solvents.
4.3.1 Selectivity can be improved by the choice of solvent (usually hexane or pentane) or mixed solvents, extraction time and temperature, and ionic strength of the solution.
4.3.2 Extraction devices can vary from the sample container itself to commercial devices specifically designed for micro-extraction. See 7.1 and 7.2.
4.3.3 A list of chlorinated organic compounds that can be determined by this practice includes both high and low boiling compounds or chemicals (see Table 1). (A) Based on the injection of chlorinated compounds in pentane solution, taking into consideration the 100:1 concentration of a water sample by the microextraction technique.
SCOPE
1.1 This practice covers standard procedures for extraction of volatile and semi-volatile organic compounds from water using small volumes of solvents.
1.2 The compounds of interest must have a greater solubility in the organic solvent than the water phase.
1.3 Not all of the solvents that can be used in micro extraction are addressed in this practice. The applicability of a solvent to extract the compound(s) of interest must be demonstrated before use.
1.4 This practice provides sample extracts suitable for any technique amenable to solvent injection such as gas chromatography or high performance liquid chromatography (HPLC).
1.5 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.6 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use. For specific hazard statements, see Section 9.
1.7 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
General Information
Relations
Standards Content (Sample)
This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: D5241 − 92 (Reapproved 2024)
Standard Practice for
Micro-Extraction of Water for Analysis of Volatile and Semi-
Volatile Organic Compounds in Water
This standard is issued under the fixed designation D5241; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope D1193 Specification for Reagent Water
D3370 Practices for Sampling Water from Flowing Process
1.1 This practice covers standard procedures for extraction
Streams
of volatile and semi-volatile organic compounds from water
D3694 Practices for Preparation of Sample Containers and
using small volumes of solvents.
for Preservation of Organic Constituents
1.2 The compounds of interest must have a greater solubil-
D3856 Guide for Management Systems in Laboratories
ity in the organic solvent than the water phase. 3
Engaged in Analysis of Water (Withdrawn 2024)
D3973 Test Method for Low-Molecular Weight Halogenated
1.3 Not all of the solvents that can be used in micro
extraction are addressed in this practice. The applicability of a Hydrocarbons in Water
D4210 Practice for Intralaboratory Quality Control Proce-
solvent to extract the compound(s) of interest must be demon-
strated before use. dures and a Discussion on Reporting Low-Level Data
(Withdrawn 2002)
1.4 This practice provides sample extracts suitable for any
D4448 Guide for Sampling Ground-Water Monitoring Wells
technique amenable to solvent injection such as gas chroma-
D5175 Test Method for Organohalide Pesticides and Poly-
tography or high performance liquid chromatography (HPLC).
chlorinated Biphenyls in Water by Microextraction and
1.5 The values stated in SI units are to be regarded as
Gas Chromatography
standard. No other units of measurement are included in this
standard. 3. Summary of Practice
1.6 This standard does not purport to address all of the 3.1 This practice employs liquid/liquid extraction to isolate
safety concerns, if any, associated with its use. It is the
compounds of interest. The sample is added to an extraction
responsibility of the user of this standard to establish appro- device. The solvent may be added to the sample container or an
priate safety, health, and environmental practices and deter- extraction device and extracted for a period of 5 min. The
mine the applicability of regulatory limitations prior to use.
solvent is then ready for analysis. If required, the pH may be
For specific hazard statements, see Section 9. adjusted and salt may be added prior to extraction to increase
1.7 This international standard was developed in accor-
the extraction specificity and efficiency.
dance with internationally recognized principles on standard-
3.2 The solvent extract may be further processed using
ization established in the Decision on Principles for the
sample clean-up and concentration techniques. The analytes in
Development of International Standards, Guides and Recom-
the solvent may be analyzed using instrumental methods for
mendations issued by the World Trade Organization Technical
specific volatile or semivolatile organic compounds. This
Barriers to Trade (TBT) Committee.
practice does not include sample extract clean-up methods.
2. Referenced Documents
4. Significance and Use
2.1 ASTM Standards:
4.1 This practice provides a general procedure for the
D1129 Terminology Relating to Water
solvent extraction of volatile and semi-volatile organic com-
pounds from a water matrix. Solvent extraction is used as the
This practice is under the jurisdiction of ASTM Committee D19 on Water and
initial step in the solvent extraction of organic constituents for
is the direct responsibility of Subcommittee D19.06 on Methods for Analysis for
Organic Substances in Water. the purpose of quantifying extractable organic compounds.
Current edition approved April 1, 2024. Published April 2024. Originally
4.2 Typical detection limits that can be achieved using
approved in 1992. Last previous edition approved in 2017 as D5241 – 92 (2017).
DOI: 10.1520/D5241-92R24. micro-extraction techniques with gas chromatography (GC)
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Standards volume information, refer to the standard’s Document Summary page on The last approved version of this historical standard is referenced on
the ASTM website. www.astm.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D5241 − 92 (2024)
with flame ionization detector (FID), electron capture detector 5.1.2 Plastics other than PTFE-fluorocarbon should be
(ECD), or with a mass spectrometer (GC/MS) range from avoided. They are a significant source of interference and can
milligrams per litre (mg/L) to nanograms per litre (ng/L). The adsorb some organics.
detection limit, linear concentration range, and sensitivity of 5.1.3 A field blank prepared from water and carried through
the test method for a specific organic compound will depend sampling, subsequent storage, and handling can serve as a
upon the sample clean-up, injection volume, solvent to sample check on sources of interferences from the containers.
ratio, solvent concentration methods used, and the determina-
5.2 When performing analyses for specific organic
tive technique employed.
compounds, matrix interferences may be caused by materials
4.3 Micro-extraction has the advantage of speed, simple and constituents that are coextracted from the sample. The
extraction devices, and the use of small amounts of sample and extent of such matrix interferences will vary considerably
solvents. depending on the sample and the specific instrumental analysis
4.3.1 Selectivity can be improved by the choice of solvent method used. Matrix interferences may be reduced by the
(usually hexane or pentane) or mixed solvents, extraction time choice of extracting solvent, or by using a clean-up technique
and temperature, and ionic strength of the solution.
on the extract.
4.3.2 Extraction devices can vary from the sample container
itself to commercial devices specifically designed for micro- 6. Selection of the Extraction Solvent
extraction. See 7.1 and 7.2.
6.1 The selection of solvent for extraction will depend upon
4.3.3 A list of chlorinated organic compounds that can be
many factors, including the following:
determined by this practice includes both high and low boiling
6.1.1 Solvent compatibility with analytical instrumentation,
compounds or chemicals (see Table 1).
6.1.2 Solubility of the organic constituent in the solvent
versus its solubility in water. The water/solvent ratio has been
5. Interferences
found to be critical to achieve optimum recovery of some
5.1 Solvents, reagents, glassware, and other sample process-
analytes (see Test Method D3973). Typical solvent to sample
ing hardware may yield discrete artifacts or elevated baselines
ratios are 1 to 10 or 20. The ratio should be optimized for
that can cause poor precision and accuracy. See Terminology
maximum recovery or detection of an analyte, or both,
D1129.
6.1.3 The availability and purity of the solvent,
5.1.1 Glassware should be washed with detergent, rinsed
6.1.4 The boiling point and viscosity of the solvent,
with water, followed by a rinse with distilled in glass acetone.
6.1.5 The tendency of the solvent and matrix to form
Final drying is done by air or 103 °C oven. Additional cleaning
emulsions, and
steps may be required when the analysis requires levels of
6.1.6 Solubility of the solvent in the water.
micrograms per litre or below. Once the glassware has been
6.2 The analyst should analyze sample blank using the
cleaned, it should be used immediately or stored wrapped in
potential solvent and demonstrate a recovery using a spiking
aluminum foil (shiny side out) or by stretching a sheet of
procedure in the matrix of interest before applying this
PTFE-fluorocarbon over the top for storage.
procedure for sample analysis.
7. Apparatus
TABLE 1 Results of Flame Ionization Detector (FID) and Electron
A
Capture Detector (ECD) Detectability
7.1 Volumetric Flasks, 110 mL.
NOTE 1—Lowest levels tested.
7.2 Liquid/Liquid Extractor.
FID (μg/L) ECD (ng/L)
7.3 Vials, auto sampler with septa and caps. Vials should be
Trichloroethene 2 5
compatible with the automatic sample injector and should have
Tetrachloroethene 2 5
Monochlorobenzene 1 500
an internal volume of not greater than 2 mL.
para-Chlorobenzotrifluoride 1 5
ortho-Chlorobenzotrifluoride 1 5 7.4 Vial, crimper.
ortho-Chlorotoluene 1 100
7.5 Bottles, glass narrow mouth with TFE fluorocarbon-
meta-Chlorotoluene 1 100
para-Chlorotoluene 1 100
lined septum screw caps.
1,2,4-Trichlorobenzene 1 5
1,2,3-Trichlorobenzene 1 5 7.6 Shaker, wrist.
Hexachlorobutadiene 1 5
1,2,4,5-Tetrachlorobenzene 1 5
8. Reagents
Hexachlorocyclopentadiene 2 5
2,4,5-Trichlorophenol 2 100
8.1 Purity of Water—Unless otherwise indicated, reference
1,2,3,4-Tetrachlorobenzene 1 5
to water shall be understood to mean reagent water conforming
alpha-Hexachlorocyclohexane 1 5
beta-Hexachlorocyclohexane 1 5
to Type II of Specification D1193.
Hexachlorobenzene 1 5
gamma-Hexachlorocyclohexane 1 5
delta-Hexachlorocyclohexane 1 5
A
Cassia, available from Baxter, 1430 Waukegan Rd., McGaw Park, IL 60085, or
Based on the injection of chlorinated compounds in pentane solution, taking into
equivalent, has been found suitable for this purpose.
consideration the 100:1 concentration of a water sample by the microextraction
Available from J & W Scientific, 91 Blue Ravine Rd., Folsom, CA 95630, or
technique.
equivalent, has been found suitable for this purpose.
D5241 − 92 (2024)
8.2 Chromatographic grade solvents that have been distilled 10.3 Sample Storage:
in glass should be used in all tests. Other grades may be used, 10.3.1 All samples must be iced or refrigerated to 4 °C from
if it is first ascertained that the solvent is of sufficiently high the time of collection until ready for extraction.
purity to permit its use without lessening the accuracy of the 10.3.2 Samples should be stored in a clean dry place away
determination. from samples containing high concentrations of organics.
8.3 The extraction solvent of choice should be appropriate 10.4 Sample Preservation:
for the matrix and compounds of interest. This choice is 10.4.1 Some compounds are susceptible to rapid biological
dependent upon the chemical properties of the organic con- degradation under certain environmental conditions. If biologi-
stituents of interest and the matrix being extracted. cal activity is expected, adjust the pH of the sample to about 2
by adding HCl. The constituent of concern must be stable
8.4 The spiking, standard materials and surrogates should
under acid conditions. For additional information, see Practices
be reagent or ACS grade or better. When they are not available
D3694.
as reagent grade, they should have an assay of 90 % or better.
10.4.2 If residual chlorine is present, add sodium thiosulfate
8.5 Hydrochloric Acid (HCl) or Sulfuric Acid Solution—
as a preservative (30 mg/4 oz bottle).
(H SO ) (1:1 v:v), prepared by slowly adding 50 mL of acid to
2 4
NOTE 2—Any reagents added to the sample at the time of collection or
50 mL of water.
before analysis must be added to the laboratory blank and standard. See
8.6 Sodium Hydroxide Solution (NaOH), prepared by dis-
11.3.
solving 40 g NaOH in water and diluting to 100 mL.
11. Quality Control
8.7 Sodium Sulfate (Na SO ), reagent grade, granular,
2 4
anhydrous, prepared by heating to 300 °C under a flow of 11.1 Minimum quality control requirements are an initial
nitrogen. demonstration of laboratory capability, analysis of method
blanks, a laboratory fortified blank, a laboratory fortified
NOTE 1—Nitrogen is only required when trace work using ECD is
sample matrix and, if available, quality control samples. For a
required.
general discussion of good laboratory practices, see Guide
8.8 Magnesium Sulfate (MgSO ), reagent grade, granular,
D3856 and Practice D4210.
anhydrous, prepared by heating at 400 °C for a minimum of 4 h
11.2 Select a representative spike concentration (about three
in a shallow tray to eliminate interfering organics.
times the estimated detection limit or expected concentration)
8.9 Sodium Chloride (NaCl), reagent grade, granular.
for each analyte. Extract according to Section 12 and analyze.
8.10 Sodium Thiosulfate—(Na S O ), reagent grade, granu-
2 2 3
11.3 Method blanks must be prepared using reagent grade
lar.
water and contain all the reagents used in sample preservation
and preparation. The blanks must be carried through the entire
9. Hazards
analytical procedure with the samples. Each time a group of
9.1 The toxicity and carcinogenicity of chemicals used or
samples are run that contain different reagents or reagent
that could be used in this practice have not been precisely
concentrations, a new method blank must be run.
defined. Each chemical should be treated as a potential health
11.4 All calibration and quality control standards must be
hazard. Exposure to these chemicals should be minimized.
extracted using the same reagents, procedures, and conditions
Each laboratory is responsible for maintaining awareness of
as the samples.
OSHA regulations regarding safe handling of chemicals used
in this practice.
11.5 Precision and bias must be established for each matrix
and laboratory analytical method.
9.2 If using ether solvents, the hazard of peroxides forma-
11.5.1 Precision should be determined by splitting spiked
tion should be considered by testing for the presence of
samples or analytes in the batch into two equal portions. The
peroxide prior to use.
replicate samples should then be extracted and analyzed.
10. Sample Handling
11.5.2 Bias should be determined in the laboratory by
spiking the samples with the analytes of interest at a concen-
10.1 There are many procedures for acquiring representa-
tration three times the concentration found in the samples or
tive samples of water. The procedure chosen will be site and
less.
analysis specific. There are several guides and practices for
sampling listed in the ASTM subject index under Sampling-
NOTE 3—The bias may be decreased by keeping the temperature,
Water Applications. Two good sources are Practices D3370 shaking speed and time, ionic strength, and solvent
...
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