Standard Practice for Selection of Sorbents, Sampling, and Thermal Desorption Analysis Procedures for Volatile Organic Compounds in Air

SIGNIFICANCE AND USE
This practice is recommended for use in measuring the concentration of VOCs in ambient, indoor, and workplace atmospheres. It may also be used for measuring emissions from materials in small or full scale environmental chambers for material emission testing or human exposure assessment.
Such measurements in ambient air are of importance because of the known role of VOCs as ozone precursors, and in some cases (for example, benzene), as toxic pollutants in their own right.
Such measurements in indoor air are of importance because of the association of VOCs with air quality problems in indoor environments, particularly in relation to sick building syndrome and emissions from building materials. Many volatile organic compounds have the potential to contribute to air quality problems in indoor environments and in some cases toxic VOCs may be present at such elevated concentrations in home or workplace atmospheres as to prompt serious concerns over human exposure and adverse health effects (6).
Such measurements in workplace air are of importance because of the known toxic effects of many such compounds.
In all three environments, in order to protect the environment as a whole and human health in particular, it is necessary to take measurements of air quality as part of an overall assessment in relation to mandatory requirements.
The choices of sorbents, sampling method, and analytical methodology affect the efficiency of sorption, recovery, and quantification of individual VOCs. This practice is potentially effective for a wide range of volatile organic compounds found in air, over a wide range of volatilities and concentration levels. However, it is the responsibility of the user to ensure that the sampling, recovery, analysis, and quality control for the measurement of a specific VOC of interest are within acceptable limits. Guidance for this evaluation is part of the scope of this practice.
SCOPE
1.1 This practice is intended to assist in the selection of sorbents and procedures for the sampling and analysis of ambient (1), indoor (2) and workplace (3,4) atmospheres for a variety of common volatile organic compounds (VOCs). It may also be used for measuring emissions from materials in small or full scale environmental chambers or for human exposure assessment.
1.2 A complete listing of VOCs for which this practice has been tested, at least over part of the measurement range (1.6), is shown in Tables 1-9. For other compounds this practice shall be tested according to EN 1076 (pumped); Practice D 6246, ISO 16107, ANSI/ISEA 104, EN838 or EN 13528-1/EN 13528-2 (diffusive); or other appropriate validation protocols (Sections 13 and 14). (5,1)
1.3 This practice is based on the sorption of VOCs from air onto selected sorbents or combinations of sorbents. Sampled air is either drawn through a tube containing one or a series of sorbents (pumped sampling) or allowed to diffuse, under controlled conditions, onto the sorbent tube or tubes (diffusive or passive sampling). The sorbed VOCs are subsequently recovered by thermal desorption and analyzed by capillary gas chromatography.
1.4 This practice applies to three basic types of samplers that are compatible with thermal desorption: (1) pumped sorbent tubes containing one or more sorbents; (2) axial diffusive samplers (typically of the same physical dimensions as standard pumped sorbent tubes and containing only one sorbent); and (3) radial diffusive samplers.
1.5 This practice recommends a number of sorbents that can be packed in sorbent tubes, for use in the sampling of a wide range of different volatile organic compounds, in the range 0 to 400°C (v.p. 15 to 0.01 kPa at 25°C).
1.5.1 For pumped sampling, sorbent selection is based on breakthrough capacity. Single-bed tubes containing for example sorbent Type A3,4 are appropriate for normal alkanes from n-C6(hexane) to n-C10(decane) and substances with similar volatility (v.p. 15 to ...

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Historical
Publication Date
09-May-2003
Technical Committee
Drafting Committee
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Ref Project

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ASTM D6196-03 - Standard Practice for Selection of Sorbents, Sampling, and Thermal Desorption Analysis Procedures for Volatile Organic Compounds in Air
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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:D6196–03
Standard Practice for
Selection of Sorbents, Sampling, and Thermal Desorption
1
Analysis Procedures for Volatile Organic Compounds in Air
This standard is issued under the fixed designation D 6196; 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 (e) indicates an editorial change since the last revision or reapproval.
1. Scope 1.5.1 For pumped sampling, sorbent selection is based on
breakthrough capacity. Single-bed tubes containing for ex-
1.1 This practice is intended to assist in the selection of
3,4
ample sorbent Type A are appropriate for normal alkanes
sorbents and procedures for the sampling and analysis of
2 from n-C (hexane) to n-C (decane) and substances with
ambient (1) , indoor (2) and workplace (3, 4) atmospheres for 6 10
similar volatility (v.p. 15 to 0.3 kPa at 25°C). More volatile
a variety of common volatile organic compounds (VOCs). It
materials should be sampled on stronger sorbents, such as
may also be used for measuring emissions from materials in
3,5
sorbentTypeB .Othersorbenttypesthanthosespecifiedmay
small or full scale environmental chambers or for human
be used, if their breakthrough capacities are adequate and their
exposure assessment.
thermal desorption blanks are sufficiently small. Examples are
1.2 A complete listing of VOCs for which this practice has
given in Appendix X2. A broader range of VOCs may be
been tested, at least over part of the measurement range (1.6),
sampled using multi-bed tubes.
is shown inTables 1-9. For other compounds this practice shall
1.5.2 Guidance given for the selection of sorbents for
be tested according to EN 1076 (pumped); Practice D 6246,
pumped monitoring tubes can be applied equally well to axial
ISO 16107, ANSI/ISEA 104, EN 838 or EN 13528-1/
diffusive sampling tubes. The restriction to a single sampling
EN 13528-2 (diffusive); or other appropriate validation proto-
surface (hence single sorbent), limits the target analyte range
cols (Sections 13 and 14). (5,1)
that can be monitored by a single tube. However, the unobtru-
1.3 This practice is based on the sorption of VOCs from air
sive nature and low cost of diffusive samplers usually means
onto selected sorbents or combinations of sorbents. Sampled
that two or more samplers containing different sorbents can be
air is either drawn through a tube containing one or a series of
used in parallel without impacting study objectives.
sorbents (pumped sampling) or allowed to diffuse, under
1.5.3 The high sampling rate and associated risk of back
controlled conditions, onto the sorbent tube or tubes (diffusive
diffusion associated with radial diffusive samplers typically
or passive sampling). The sorbed VOCs are subsequently
restricts the use of these samplers to compounds of equal or
recovered by thermal desorption and analyzed by capillary gas
lower volatility than benzene. It also means that stronger
chromatography.
sorbents are generally required for these samplers when
1.4 This practice applies to three basic types of samplers
compared with either axial diffusive or pumped sorbent tubes.
that are compatible with thermal desorption: (1) pumped
1.6 This practice can be used for the measurement of
sorbent tubes containing one or more sorbents; (2) axial
airborne vapors of these volatile organic compounds over a
diffusive samplers (typically of the same physical dimensions
wide concentration range.
as standard pumped sorbent tubes and containing only one
1.6.1 With pumped sampling, this practice can be used for
sorbent); and (3) radial diffusive samplers.
the measurement of airborne vapors of VOCs in a concentra-
1.5 Thispracticerecommendsanumberofsorbentsthatcan
3 3
tion range of approximately 0.1 µg/m to 1 g/m , for individual
be packed in sorbent tubes, for use in the sampling of a wide
organic compounds in 1–10 L air samples. The method is also
range of different volatile organic compounds boiling in the
suitable for the measurement of the airborne concentrations of
range 0 to 400°C (v.p. 15 to 0.01 kPa at 25°C).
3
If you are aware of alternative sorbent types, please provide this information to
1
This practice is under the jurisdiction of ASTM Committee D22 on Sampling ASTM Headquarters. Your comments will be carefully considered at a meeting of
and Analysis of Atmospheres and is the direct responsibility of Subcommittee the responsible technical committee, which you may attend.
4
D22.05 on Indoor Air. An example of sorbent Type A known to perform as specified in this practice
Current edition approved May 10, 2003. Published July 2003. Originally is Chromosorb 106 manufactured by Manville Corp., USA and available from
approved in 1997. Last
...

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