ASTM D3687-07(2012)
(Practice)Standard Practice for Analysis of Organic Compound Vapors Collected by the Activated Charcoal Tube Adsorption Method
Standard Practice for Analysis of Organic Compound Vapors Collected by the Activated Charcoal Tube Adsorption Method
SIGNIFICANCE AND USE
Promulgations by the Federal Occupational Safety and Health Administration (OSHA) in 29 CFR 1910 designate that certain organic compounds must not be present in workplace atmospheres at concentrations above specified values.
This practice, when used in conjunction with Practice D3686, will promote needed accuracy and precision in the determination of airborne concentrations of many of the organic chemicals given in 29 CFR 1910, CDC-99-74-45, NIOSH Manual of Analytical Methods, OSHA Sampling and Analytical Methods, HSE Methods for the Determination of Hazardous Substances, and BGIA GESTIS Analytical Methods. It can be used to determine worker exposures to these chemicals, provided appropriate sampling periods are used.
Most laboratories are equipped with apparatus similar to that described in Section 7. Other apparatus can be used when analytical procedures suitable for that equipment are employed. The analytical techniques (or variations thereof) described in Sections 9-11 are in general use to analyze volatile organic compounds extracted from charcoal. Other procedures can be used when appropriate.
SCOPE
1.1 This practice covers the applications of methods for the extraction and gas chromatographic determination of organic vapors that have been adsorbed from air in sampling tubes packed with activated charcoal.
1.2 This practice is complementary to Practice D3686.
1.3 This practice is applicable for analysis of samples taken from workplace or other atmospheres provided that the contaminant adsorbs onto charcoal, that it can be adequately extracted from the charcoal, and that it can be analyzed by gas chromatography (GC). Other adsorbents and other extraction techniques are described in Practice D6196.
1.4 Organic compounds of multicomponent samples may mutually interfere during analysis. Methods to resolve interferences are given in Section 6.
1.5 The values stated in SI units are to be regarded as the 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 and health practices and determine the applicability of regulatory limitations prior to use. Specific precautions are given in 8.4, 9.2, and in A1.2.3.
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: D3687 − 07 (Reapproved 2012)
Standard Practice for
Analysis of Organic Compound Vapors Collected by the
Activated Charcoal Tube Adsorption Method
This standard is issued under the fixed designation D3687; 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 D1356Terminology Relating to Sampling and Analysis of
Atmospheres
1.1 This practice covers the applications of methods for the
D3686Practice for Sampling Atmospheres to Collect Or-
extraction and gas chromatographic determination of organic
ganic Compound Vapors (Activated Charcoal Tube Ad-
vapors that have been adsorbed from air in sampling tubes
sorption Method)
packed with activated charcoal.
D6196Practice for Choosing Sorbents, Sampling Param-
1.2 This practice is complementary to Practice D3686.
eters and Thermal Desorption Analytical Conditions for
Monitoring Volatile Organic Chemicals in Air
1.3 This practice is applicable for analysis of samples taken
from workplace or other atmospheres provided that the con- E355Practice for Gas ChromatographyTerms and Relation-
ships
taminant adsorbs onto charcoal, that it can be adequately
extracted from the charcoal, and that it can be analyzed by gas
2.2 NIOSH Standards:
chromatography (GC). Other adsorbents and other extraction
CDC-99-74-45 Documentation of NIOSH Validation
techniques are described in Practice D6196.
Tests
th 4
NIOSH Manual of Analytical Methods, 4 Ed.
1.4 Organic compounds of multicomponent samples may
mutually interfere during analysis. Methods to resolve inter-
2.3 OSHA Standards:
ferences are given in Section 6.
29 CFR 1910Code of Federal Regulations, Regulations
Relating to Labor, Occupational Safety and Health
1.5 The values stated in SI units are to be regarded as the
Administration, Department of Labor
standard.
OSHA Sampling and Analytical Methods
1.6 This standard does not purport to address all of the
2.4 UK Health and Safety Executive (HSE):
safety concerns, if any, associated with its use. It is the
Methods for the Determination of Hazardous Substances
responsibility of the user of this standard to establish appro-
(MDHS)
priate safety and health practices and determine the applica-
2.5 Berufsgenossenschaftliches Institut für Arbeitsschulz
bility of regulatory limitations prior to use. Specific precau-
tions are given in 8.4, 9.2, and in A1.2.3. (BGIA):
GESTIS Analytical Methods
1.7 This international standard was developed in accor-
dance with internationally recognized principles on standard-
3. Terminology
ization established in the Decision on Principles for the
Development of International Standards, Guides and Recom-
3.1 Definitions:
mendations issued by the World Trade Organization Technical
3.1.1 For definitions of terms used in this practice, refer to
Barriers to Trade (TBT) Committee.
the terminology specified in D1356 and E355.
2. Referenced Documents
2.1 ASTM Standards: 3
Available from the U.S. Department of Commerce, National Technical Infor-
mation Service, Port Royal Road, Springfield, VA 22161.
NIOSH Manual of Analytical Methods (NMAM), http://www.cdc.gov/niosh/
ThispracticeisunderthejurisdictionofASTMCommitteeD22onAirQuality nmam (accessed 1/2007).
andisthedirectresponsibilityofSubcommitteesD22.04onWorkplaceAirQuality. Available from Superintendent of Documents, U.S. Government Printing
Current edition approved April 1, 2012. Published July 2012. Originally Office, Washington, DC 20402.
approved in 1978. Last previous edition approved in 2007 as D3687–07. DOI: OSHA Sampling and Analytical Methods, http://www.osha.gov/dts/sltc/
10.1520/D3687-07R12. methods/index.html (accessed 1/2007).
2 7
For referenced ASTM standards, visit the ASTM website, www.astm.org, or HSE Methods for the Determination of Hazardous Substances (MDHS),
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM http://www.hse.gov.uk/pubns/mdhs/index.htm# (accessed 1/2007).
Standards volume information, refer to the standard’s Document Summary page on GESTIS Analytical Methods, http://www.hvbg.de/e/bia/gestis/analytical_
the ASTM website. methods/index.html (accessed 1/2007).
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D3687 − 07 (2012)
4. Summary of Practice 6.2 Selective solvent stripping techniques have been used
successfully to make clean and fast separations of polar,
4.1 Organic vapors that have been collected on activated
nonpolar and oxygenated compounds. A general guideline is
charcoal are extracted with carbon disulfide or another appro-
given in A1.1 and detailed procedures are given in Refs (1
priate solvent and are determined by GC using a flame
and 2).
ionizationdetector(FID).Carbondisulfideisarelativelysmall
6.3 Whennecessary,theidentityorpurityofananalytepeak
molecule that can penetrate the “ink-bottle” shaped pores of
can be confirmed by GC/mass spectrometry.
activatedcharcoal,ithasahighheatofadsorptiononactivated
charcoal which helps in displacing other adsorbed molecules,
6.4 The presence of co-adsorbed chemicals can affect the
and it is a reasonably good solvent for most, especially
recovery (extraction efficiency) of a particular analyte. Sus-
non-polar, organic molecules. Polar modifiers (such as N,N-
pectedeffectscanbetestedbyspikingtheanalytesoncharcoal
dimethylformamide) are frequently added to enhance the re-
as in Section 11.
covery of polar organic compounds. Other advantages to using
carbon disulfide include an early elution time on most GC
7. Apparatus
columns and a small FID response.
7.1 Gas chromatograph, equipped with a flame ionization
4.2 Interferences resulting from the analytes having similar
detector (FID), a temperature-programmable oven, and an
retention times during GC analysis are resolved by changing
automaticsampleinjector(autosampler).Sampleinjectionmay
the GC column, by changing the operating parameters, or by
be performed manually if necessary. Other detectors (such as
fractionating the sample using solvent extraction as described
electron capture, flame photometric, nitrogen phosphorous
in Section A1.1.
detectors) can be used when appropriate but the extraction
solvent may have to be modified.
4.3 Peak purity and identity can be confirmed using tech-
7.2 Electronic data system,orothersuitablemeanstorecord
niques such as GC/MS.
and measure detector response, to prepare calibration curves,
and to process sample results.
5. Significance and Use
7.3 GC columns, required to separate the complex mixture
5.1 Promulgations by the Federal Occupational Safety and
of possible organic chemicals. Examples of the most common
HealthAdministration (OSHA) in 29 CFR 1910 designate that
and useful GC columns are 60-m long, 0.32-mm i.d. fused
certain organic compounds must not be present in workplace
silica capillary GC columns with 0.1 to 1-µm thick (df) phases
atmospheres at concentrations above specified values.
such as 100% dimethyl polysiloxane, 95% dimethyl-5%
5.2 This practice, when used in conjunction with Practice
diphenyl polysiloxane, and polyethylene glycol.
D3686, will promote needed accuracy and precision in the
7.4 Laboratory glassware, calibrated syringes, calibrated
determination of airborne concentrations of many of the
solvent dispensers, assorted Class A pipets and volumetric
organic chemicals given in 29 CFR 1910, CDC-99-74-45,
flasks and glass automatic sample injector (autosampler) vials
NIOSH Manual of Analytical Methods, OSHA Sampling and
with PTFE septum caps to contain analytical standards and
Analytical Methods, HSE Methods for the Determination of
samples.
Hazardous Substances, and BGIA GESTIS Analytical Meth-
ods. It can be used to determine worker exposures to these
8. Reagents
chemicals, provided appropriate sampling periods are used.
8.1 Analytical standards, reagent grade or better, typically
5.3 Mostlaboratoriesareequippedwithapparatussimilarto
97-99+%.
that described in Section 7. Other apparatus can be used when
8.2 Carbon disulfide, reagent grade or better, typically
analytical procedures suitable for that equipment are em-
99.9% with low benzene content.
ployed. The analytical techniques (or variations thereof) de-
scribed in Sections9–11 are in general use to analyze volatile
8.3 Internal standard, reagent grade or better, typically
organic compounds extracted from charcoal. Other procedures
99+%, p-cymene and 1-phenyl hexane are often used. Other
can be used when appropriate.
internal standard reagents can be used providing that they not
appear in air samples and that they are fully tested.
6. Interferences
8.4 Extraction solvent, usually consists of 0.25 microlitres
6.1 Any chemical that produces an FID response and has a of internal standard per milliliter of carbon disulfide. Other
similar retention time as the analyte is a potential interference. extraction solvents can be used provided they are fully tested.
Ifpotentialinterferenceswerereportedwhenthesampleswere (Warning—Carbon disulfide is toxic and extremely
received they should be considered before the samples are
extracted. Generally, gas chromatographic conditions such as
the type of GC column (phase) or operating parameters can be 9
The boldface numbers in parentheses refer to the list of references at the end of
changed to resolve interferences. this standard.
D3687 − 07 (2012)
flammable, as are many of the organic chemicals to be same solution if applicable. Prepare independent analytical
analyzed.Work with these chemicals in a properly functioning standards with material obtained from a separate vendor to test
laboratory hood.) the purity of the source material and the accuracy of the
standard preparation.
9. Calibration
9.7 Analyze the standards using the same temperature
9.1 In general, follow the manufacturer’s manual and safety
programusedin9.5.Comparethechromatogramstobecertain
instructions to set up the gas chromatograph.Always use high
the analytes are resolved. Generally, chromatographic condi-
purity gases and high quality gas purifiers.
tions can be altered to separate interferences.
9.2 Install the selected GC column and set the linear
9.8 Use an internal standard (ISTD) calibration method for
velocity of the carrier gas following manufacturer’s instruc-
most organic compounds. An internal standard calibration
tions. Set the injector split ratio at 10:1 or at some other
function is incorporated with most electronic data systems.
appropriate ratio. The most commonly used capillary GC
Calibration curves for each analyte can be constructed by
carrier gas is hydrogen. Set the injector, detector, and column
plotting detector response of standards (y axis) against mass
oventemperaturesappropriatefortheselectedGCcolumn.Itis
per standard (x axis). FID response is usually linear; therefore,
often useful to heat the GC column at 10-20°C below the
linearregressionisgenerallyappropriatetofindtheequationof
expected maximum operating temperature of the column for
the best-fit line for the calibration curve. Program the data
about two hours before any analysis is performed. Before
system to calculate results in terms of micrograms per sample.
analyzing standards or samples, place a fresh septum into the
This is appropriate because both standards and samples are
injection port of the chromatograph. Replace the septum daily
preparedin1.00mLofextractionsolvent.Typically,resultsfor
or when necessary. Septum failure is a frequent cause of
standards (other than for the reporting limit) calculated from
inconsistent FID response and changes in chromatography.
the calibration curve will deviate from their theoretical
(Warning—Hydrogen gas is explosive and extremely flam-
amounts by not more than 610%. Usually, deviation for the
mable. It is absolutely essential that the gas chromatograph be
reporting limit is no more than 625%. Prepare and analyze
leak free.)
fresh standards as necessary.Analyze a fresh set of calibration
9.3 Makesurethattheelectronicdatasystemisproperlyset
standards with each sample set, or with a day’s sequence of
to collect analytical data.
sample sets.
9.4 Prepare separate solutions containing 1 mL of each
10. Sample Preparation
analyte per 1 mL of extraction solvent. These solutions are
used to determine GC column retention time of the analytes.
10.1 Consider potential analytical interferences that were
9.5 Analyze these solutions and a reagent blank (without reported when the samples were received. Make certain that
the extraction efficiency (also called desorption efficiency) for
charcoal) using an appropriate GC column and an appropriate
oven temperature program to determine GC column retention all requested analyses has been determined (as described in
Section 11) before extracting the samples.
times for each analyte and for the internal standard. It may be
usefultocreateanin-house“columnmap”foreachGCcolumn
10.2 Most charcoal tubes have two sections and each
listing retention times for each analyte determined using a
section is quantitively transferred to a separate labeled au-
standard temperature program and a standard carrier gas linear
tosampler vial. Some charcoal tubes have three sections and
velocity.
each of the three sections should be similarly transferred to a
9.6 Prepare analytical standards that bracket the expected
separate labeled autosampler vial.
range of sample results for each of the analytes by injection of
10.3 Remove the plastic cap from end of the charcoal with
microliter amounts of the analytes into the extraction solution.
the back-up section(s) of the sampling tube.
Forexample:iftherequestedanalyteistoluene,theairvolume
sampled with a charcoal tube is 12 L, the density of toluene is 10.4 Remove the plug that holds the back-up section in
0.866 g/mL, the purity of the analytical standard is 99%, and
place and transfer the charcoal to an appropriately labeled vial
the exposure limit (target concentration) is 200 ppm (753 and close the vial. Similarly transfer the second back-up
mg/m ). Calculate the mass of toluene equivalent to the target
section (if present) to a separate labeled vial and close the vial.
concentrationbymultiplyingtheexposurelimitbythecharcoal (Asmall crochet hook is a convenient device for removing the
3 3
sample air volume (753 mg/m ×0.012 m =9.04 mg per
plugsfromthesamplers,orahookcanbefashionedfromafine
sample). Prepare a standard at approximately the target con- (18 to 20-gauge) steel wire or a 3-in. (76-mm) No. 20
centration by diluting 10.00 µL of toluene to 1.00 mL with
hyp
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