ASTM D5790-95(2012)
(Test Method)Standard Test Method for Measurement of Purgeable Organic Compounds in Water by Capillary Column Gas Chromatography/Mass Spectrometry
Standard Test Method for Measurement of Purgeable Organic Compounds in Water by Capillary Column Gas Chromatography/Mass Spectrometry
SIGNIFICANCE AND USE
Purgeable organic compounds have been identified as contaminants in treated drinking water, wastewater, ground water, and Toxicity Characteristic Leaching Procedure (TCLP) leachate. These contaminants may be harmful to the environment and to people. Purge and trap sampling is a generally applicable procedure for concentrating these components prior to gas chromatographic analysis.
SCOPE
1.1 This test method covers the identification and simultaneous measurement of purgeable volatile organic compounds. It has been validated for treated drinking water, wastewater, and ground water. This test method is not limited to these particular aqueous matrices; however, the applicability of this test method to other aqueous matrices must be demonstrated.
1.2 This test method is applicable to a wide range of organic compounds that have sufficiently high volatility and low water solubility to be efficiently removed from water samples using purge and trap procedures. Table 1 lists the compounds that have been validated for this test method. This test method is not limited to the compounds listed in Table 1; however, the applicability of the test method to other compounds must be demonstrated.
1.3 Analyte concentrations up to approximately 200 μg/L may be determined without dilution of the sample. Analytes that are inefficiently purged from water will not be detected when present at low concentrations, but they can be measured with acceptable accuracy and precision when present in sufficient amounts.
1.4 Analytes that are not separated chromatographically, but that have different mass spectra and noninterfering quantitation ions, can be identified and measured in the same calibration mixture or water sample. Analytes that have very similar mass spectra cannot be individually identified and measured in the same calibration mixture or water sample unless they have different retention times. Coeluting compounds with very similar mass spectra, such as structural isomers, must be reported as an isomeric group or pair. Two of the three isomeric xylenes are examples of structural isomers that may not be resolved on the capillary column, and if not, must be reported as an isomeric pair.
1.5 It is the responsibility of the user to ensure the validity of this test method for untested matrices.
1.6 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.
1.7 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 and health practices and determine the applicability of regulatory limitations prior to use.
General Information
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Standards Content (Sample)
NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation: D5790 − 95 (Reapproved 2012)
Standard Test Method for
Measurement of Purgeable Organic Compounds in Water by
Capillary Column Gas Chromatography/Mass Spectrometry
This standard is issued under the fixed designation D5790; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope 1.6 The values stated in SI units are to be regarded as the
standard. The values given in parentheses are for information
1.1 This test method covers the identification and simulta-
only.
neous measurement of purgeable volatile organic compounds.
1.7 This standard does not purport to address all of the
It has been validated for treated drinking water, wastewater,
safety concerns, if any, associated with its use. It is the
and ground water. This test method is not limited to these
responsibility of the user of this standard to establish appro-
particular aqueous matrices; however, the applicability of this
priate safety, health, and environmental practices and deter-
test method to other aqueous matrices must be demonstrated.
mine the applicability of regulatory limitations prior to use.
1.2 Thistestmethodisapplicabletoawiderangeoforganic
1.8 This international standard was developed in accor-
compounds that have sufficiently high volatility and low water
dance with internationally recognized principles on standard-
solubility to be efficiently removed from water samples using
ization established in the Decision on Principles for the
purge and trap procedures. Table 1 lists the compounds that
Development of International Standards, Guides and Recom-
havebeenvalidatedforthistestmethod.Thistestmethodisnot
mendations issued by the World Trade Organization Technical
limited to the compounds listed in Table 1; however, the
Barriers to Trade (TBT) Committee.
applicability of the test method to other compounds must be
demonstrated.
2. Referenced Documents
1.3 Analyte concentrations up to approximately 200 µg/L
2.1 ASTM Standards:
may be determined without dilution of the sample. Analytes
D1129Terminology Relating to Water
that are inefficiently purged from water will not be detected
D2777Practice for Determination of Precision and Bias of
when present at low concentrations, but they can be measured
Applicable Test Methods of Committee D19 on Water
with acceptable accuracy and precision when present in suffi-
D3871Test Method for Purgeable Organic Compounds in
cient amounts.
Water Using Headspace Sampling
D3973TestMethodforLow-MolecularWeightHalogenated
1.4 Analytesthatarenotseparatedchromatographically,but
Hydrocarbons in Water
thathavedifferentmassspectraandnoninterferingquantitation
D4210Practice for Intralaboratory Quality Control Proce-
ions, can be identified and measured in the same calibration
dures and a Discussion on Reporting Low-Level Data
mixture or water sample.Analytes that have very similar mass
(Withdrawn 2002)
spectra cannot be individually identified and measured in the
E355PracticeforGasChromatographyTermsandRelation-
same calibration mixture or water sample unless they have
ships
different retention times. Coeluting compounds with very
2.2 Other Document:
similar mass spectra, such as structural isomers, must be
Code of Federal Regulations40 CFR Part 261
reportedasanisomericgrouporpair.Twoofthethreeisomeric
xylenes are examples of structural isomers that may not be
3. Terminology
resolved on the capillary column, and if not, must be reported
3.1 Definitions—For definitions of terms used in this test
as an isomeric pair.
method, refer to Definitions D1129 and Practice E355.
1.5 It is the responsibility of the user to ensure the validity
of this test method for untested matrices.
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
This test method is under the jurisdiction ofASTM Committee D19 on Water Standards volume information, refer to the standard’s Document Summary page on
andisthedirectresponsibilityofSubcommitteeD19.06onMethodsforAnalysisfor the ASTM website.
Organic Substances in Water. The last approved version of this historical standard is referenced on
Current edition approved June 15, 2012. Published June 2012. Originally www.astm.org.
approved in 1995. Last previous edition approved in 2006 as D5790–95 (2006). Available from the Superintendent of Documents, U.S. Government Printing
DOI: 10.1520/D5790-95R12. Office, Washington, DC 20402.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D5790 − 95 (2012)
3.2 Definitions of Terms Specific to This Standard: reagent blank is used to determine if test method analytes or
other interferences are present in the laboratory environment,
3.2.1 calibration standard—a solution prepared from the
the reagents, or the apparatus.
primarydilutionstandardsolutionandstockstandardsolutions
oftheinternalstandardsandsurrogateanalytes.Thecalibration
3.2.10 primary dilution standard solution—a solution of
standards are used to calibrate the instrument response with
severalanalytespreparedinthelaboratoryfromstockstandard
respect to analyte concentration.
solutionsanddilutedasneededtopreparecalibrationsolutions
and other needed analyte solutions.
3.2.2 field duplicates —two separate samples collected at
the same time and place under identical circumstances and
3.2.11 purgeable organic—any organic material that is re-
treated exactly the same throughout field and laboratory
moved from aqueous solution under the purging conditions
procedures. Analysis of field duplicates gives an indication of
described in this test method.
the precision associated with sample collection, preservation,
3.2.12 quality control sample—a sample matrix containing
and storage, as well as with laboratory procedures.
test method analytes or a solution of method analytes in a
3.2.3 field reagent blank—reagent water placed in a sample water-miscible solvent that is used to fortify reagent water or
container,takentothefieldalongwiththesamples,andtreated environmental samples.The quality control sample is obtained
asasampleinallrespects,includingexposuretosamplingsite from a source external to the laboratory and is used to check
conditions,storage,preservation,andallanalyticalprocedures. laboratoryperformancewithexternallypreparedtestmaterials.
The purpose of the field reagent blank is to determine if test
3.2.13 stock standard solution—a concentrated solution
method analytes or other interferences are present in the field
containing a single certified standard that is a test method
environment.
analyte prepared in the laboratory with an assayed reference
compound. Stock standard solutions are used to prepare
3.2.4 internal standard—a pure analyte added to a solution
primarydilutionstandards.Commerciallyavailablestockstan-
in a known amount, that is used to measure the relative
dard solutions may be used.
responses of other test method analytes and surrogates that are
components of the same solution. The internal standard must
3.2.14 surrogate analyte—a pure analyte that is extremely
be an analyte that is not a sample component.
unlikely to be found in any sample, that is added to a sample
aliquot in a known amount, and is measured with the same
3.2.5 laboratory duplicates—two sample aliquots taken in
procedures used to measure other components.The purpose of
theanalyticallaboratoryandanalyzedseparatelywithidentical
asurrogateanalyteistomonitortestmethodperformancewith
procedures. Analysis of laboratory duplicates gives an indica-
each sample.
tionoftheprecisionassociatedwithlaboratoryprocedures,but
notwithsamplecollection,preservation,orstorageprocedures.
4. Summary of Test Method
3.2.6 laboratory-fortified blank—an aliquot of reagent wa-
4.1 Volatile organic compounds with low water-solubility
ter to which known quantities of the test method analytes are
are purged from the sample matrix by bubbling an inert gas
added in the laboratory. The laboratory-fortified blank is
through the aqueous sample. Purged sample components are
analyzed exactly like a sample, and its purpose is to determine
trapped in a tube containing suitable sorbent materials. When
whether the methodology is in control and whether the
purgingiscomplete,thesorbenttubeisheatedandbackflushed
laboratory is capable of making accurate and precise measure-
with inert gas to desorb the trapped sample components into a
ments at the required detection limit.
capillary gas chromatography (GC) column interfaced to a
3.2.7 laboratory-fortified sample matrix—an aliquot of an
mass spectrometer (MS). The GC column is temperature
environmental sample to which known quantities of the test
programmed to separate the test method analytes which are
method analytes are added in the laboratory. The laboratory-
then detected with the MS. Compounds eluting from the GC
fortified sample matrix is analyzed exactly like a sample, and
column are identified by comparing their measured mass
itspurposeistodeterminewhetherornotthesamplematrixor
spectra and retention times to reference spectra and retention
the addition of preservatives or dechlorinating agents to the
times in a database. Reference spectra and retention times for
sample contributes bias to the analytical results. The back-
analytes are obtained by the measurement of calibration
ground concentrations of the analytes in the sample matrix
standards under the same conditions used for the samples.The
must be determined in a separate aliquot, and the measured
concentration of each identified component is measured by
values in the laboratory-fortified sample matrix must be
relating the MS response of the quantitation ion produced by
corrected for background concentrations.
that compound to the MS response of the quantitation ion
3.2.8 laboratory performance check solution—a solution of
produced by a compound that is used as an internal standard.
one or more compounds (analytes, surrogates, internal
Surrogate analytes, whose concentrations are known in every
standard, or other test compounds) used to evaluate the
sample, are measured with the same internal standard calibra-
performanceoftheinstrumentsystemwithrespecttoadefined
tion procedure.
set of test method criteria.
5. Significance and Use
3.2.9 laboratory reagent blank—an aliquot of reagent water
that is treated exactly as a sample including exposure to all 5.1 Purgeable organic compounds have been identified as
glassware, equipment, solvents, reagents, internal standards, contaminants in treated drinking water, wastewater, ground
andsurrogatesthatareusedwithothersamples.Thelaboratory water,andToxicityCharacteristicLeachingProcedure(TCLP)
D5790 − 95 (2012)
leachate. These contaminants may be harmful to the environ- analyte from one sample to the next. The effect was observed
ment and to people. Purge and trap sampling is a generally when samples containing 1 µg/L of analyte were analyzed
applicable procedure for concentrating these components prior immediately after samples containing 20 µg/L of analyte. For
to gas chromatographic analysis. that reason, when low concentrations of analytes are measured
in a sample, it is very important to examine the results of the
6. Interferences
preceding samples and interpret the low-concentration results
accordingly.Onepreventivetechniqueisbetween-samplerins-
6.1 During analysis, major contaminant sources are volatile
materials in the laboratory and impurities in the inert purging ing of the purging apparatus and sample syringes with two
portionsofreagentwater.Afteranalysisofasamplecontaining
gas and in the sorbent trap. Avoid the use of plastic tubing or
thread sealants other than PTFE, and avoid the use of flow high concentrations of volatile organic compounds, one or
morelaboratoryreagentblanksshouldbeanalyzedtocheckfor
controllers with rubber components in the purging device.
These materials out-gas organic compounds that will be cross contamination. After analyzing a highly contaminated
sample, it may be necessary to use methanol to clean the
concentrated in the trap during the purge operation. Analyses
of laboratory reagent blanks provide information about the sample chamber, followed by heating in an oven at 105°C.
presenceofcontaminants.Whenpotentialinterferingpeaksare
6.3 Samples can be contaminated by diffusion of volatile
noted in laboratory reagent blanks, the analyst should change
organics through the septum seal into the sample during
the purge gas source and regenerate the molecular sieve purge
shipment and storage. The analytical and sample storage area
gas filter. Reagents should also be checked for the presence of
should be isolated from all atmospheric sources of volatile
contaminants. Subtracting blank values from sample results is
organic compounds, otherwise random background levels may
not permitted.
result. Since methylene chloride will permeate through PTFE
6.2 Interfering contamination may occur when a sample tubing, all gas chromatography carrier gas lines and purge gas
containinglowconcentrationsofvolatileorganiccompoundsis plumbing should be constructed of stainless steel or copper
analyzed immediately after a sample containing higher con- tubing. Personnel who have been working directly with sol-
centrations of volatile organic compounds. Experience gained vents such as those used in liquid/liquid extraction procedures
from the test method validation has shown that there is a should not be allowed into the analytical area until they have
carryover of approximately 2% of the concentration of each washed and changed their clothing.
TABLE 1 Compounds Validated for This Test Method
Secondary Quantitation Approximate Elution
Compound CAS Registry Number Primary Quantitation Ion
Ion Order
Benzene 71-43-2 78 77 20
Bromobenzene 108-86-1 156 77, 158 44
Bromochloromethane 74-97-5 128 49, 130 16
Bromodichloromethane 75-27-4 83 85, 127 25
Bromoform 75-25-2 173 175, 252 41
Bromomethane 74-83-9 94 96 4
n-butylbenzene 104-51-8 91 134 57
sec-butylbenzene 135-98-8 105 134 53
tert-butylbenzene 98-06-6 119 91 52
Carbon disulfide 75-15-0 76 78 8
Carbon tetrachloride 56-23-5 117 119 19
Chlorobenzene 108-90-7 112 77, 114 35
Chloroethane 75-00-3 64 66 5
Chloroform 67-66-3 83 85 15
Chloromethane 74-87-3 50 52 2
2-chlorotoluene 95-49-8 91 126 47
4-chlorotoluene 106-43-4 91 126 50
Dibromochloromethane 124-48-1 129 127 33
1,2-dibromo-3-chloropropane 96-12-8 75 155, 157 60
1,2-dibromoethane 106-93-4 107 109, 188 34
Dibromomethane 74-95-3 93 95, 174
...
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