A sampling method for alpha-methyl styrene in air has been validated for concentration levels from 0.5 to 100 ppm and for exposure times from 1 through 8 hours. The 575-003 passive sampler used contains a sample medium of Anasorb ® 727. Desorption was with carbon disulfide and analysis by gas chromatography with flame ionization detection (GC-FID). The analytical recovery over the range of 0.5 to 100 ppm (13 to 2725 µg) was 101%. The sampling rate is 12.6 ml/min. Samples can be taken from 10° C to 40° C. Minimum recommended sampling time is 15 minutes. Maximum recommended sampling time is 8 hours. Samples were stable for up to 14 days when stored at room temperature or in a refrigerator (4 ° C). A full validation of styrene was done according to NIOSH Protocol 1 and a partial NIOSH validation by the bi-level procedure was conducted for alpha-methyl styrene and other higher members of this homologous series. Two samples were validated simultaneously. The 575-002 sampler (containing Anasorb 747) has greater capacity, and can be used where more volatile compounds (e.g., acetone) are present. The 575-003 sampler has the better recovery and is, therefore, more useful at low concentrations or for measuring STELs. The 575-003 sampler should not be used to sample compounds with boiling points below that of styrene.

Coconut-shell activated carbon is the sorbent of choice in sample tubes for collecting the majority of organic compounds present in workplace atmospheres. However, the surface characteristics of coconut carbon are not well suited to the sampling of certain polar and reactive compounds. Two new sorbents are described and evaluated experimentally to determine whether they are suitable for sampling acetone and 2-butanone. Anasorb 747 is a proprietary, synthetic, beaded active carbon. Sample capacity, desorption efficiency, and storage stability were found to be acceptable in the case of 2-butanone. Good results were also obtained with acetone, except that adsorbed sample was found to migrate between front and rear sections of the tube. Anasorb CMS is a carbon molecular sieve derived from Saran-type precursors. Sample capacity, desorption efficiency, and storage stability were found to be acceptable in the case of both acetone and 2-butanone. In general, the experimental results fit existing theories of adsorption and desorption well. No justification could be found for the use of anhydrous magnesium sulfate as a dessicant in the desorption step of analysis of either sorbent. Harper, M.; Kimberland, M.L.; Orr, R.J.; Guild, L.V.: An Evaluation of Sorbents for Sampling Ketones in Workplace Air. 8(4):293-304; 1993.

Validation of passive monitors is essential to ensure accurate determination of airborne chemical levels. To assist manufacturers and users, the National Institute for Occupational Safety and Health (NIOSH) and the Health and Safety Executive (HSE) have developed comprehensive protocols for the validation of passive monitors. These protocols are extensive and costly to perform on individual chemicals, requiring 350 samples. With multiple analyses and standards, this results in nearly 1600 gas chromatographic tests. The present work considers the value of a bi-level validation approach for a series of chemically related compounds, i.e., members of a homologous series. This bi-level approach includes a full protocol validation on key compounds followed by a partial validation on other members of the series. If accurate sampling can be assured by this procedure, then the cost of validation in time and resources can be reduced by 75 percent and many more chemical hazards can be sampled with confidence. Twenty-eight compounds in three homologous series were evaluated on an SKC passive monitor. Full protocol validation was done on six compounds and a partial validation was done on the remaining twenty-two compounds. Studies in the partial validation included sampling rate and capacity, analytical recovery, and interference effects. The underlying premises for bi-level validation were considered. A literature search and laboratory experiments were conducted to verify these premises. The results would indicate that a bi-level validation procedure assures reliable sampling accuracy for the three hydrocarbon series studied and suggests that this technique could be extended to other series.

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTGas Chromatographic Analysis of Aryl Grignard ReagentsL. V. Guild, C. A. Hollingsworth, D. H. McDaniel, and J. H. WotizCite this: Anal. Chem. 1961, 33, 9, 1156–1157Publication Date (Print):August 1, 1961Publication History Published online1 May 2002Published inissue 1 August 1961https://pubs.acs.org/doi/10.1021/ac60177a007https://doi.org/10.1021/ac60177a007research-articleACS PublicationsRequest reuse permissionsArticle Views156Altmetric-Citations7LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose Get e-Alerts

A sampling method for ethyl tert-butyl ether (tert-butyl ethyl ether, TBEE) in air has been validated for concentration levels from 0.4 to 140 ppm and for exposure times from 30 minutes to 8 hours. The 575-001 passive sampler used has a sample medium of Coconut Charcoal. Desorption was with carbon disulfide and analysis by gas chromatography with flame ionization detection (GC-FID). The analytical recovery over the range of 0.4 to 140 ppm (11.3 to 3750 µg) was 101%. The sampling rate is 13.1 ml/min. Samples can be taken from 10° C to 40° C. Minimum recommended sampling time is 15 minutes. Maximum recommended sampling time is 8 hours. A full validation of methyl tert-butyl ether was done according to NIOSH protocol 1 and a partial NIOSH validation by the bi-level procedure was conducted for TBEE and other higher members of this homologous series.

A sampling method for Methyl Isobutyl Ketone in air has been validated for concentration levels from 5 to 100 ppm and for exposure times from 7.5 minutes to 8 hours. The 575-002 passive sampler used has a sample medium of Anasorb ® 747. Desorption was with carbon disulfide and analysis by gas chromatography with flame ionization detection. The analytical recovery over the range of 5 to 100 ppm (146-2630 µg) was 94.6% with a relative standard deviation of 7.59%. The sampling rate is 13.5 ml/min. Samples can be taken from 10°C to 40° C.

A sampling method for Methyl Methacrylate in air has been validated for concentration levels from 10 to 200 ppm and for exposure times from 7.5 minutes to 8 hours. The 575-002 passive sampler used has a sample medium of Anasorb ® 747. Desorption was with carbon disulfide and analysis by gas chromatography with flame ionization detection. The analytical recovery over the range of 10 to 200 ppm (250 to 6400 µg) was 100.5% with a relative standard deviation of 5.51%. The sampling rate is 13.1 ml/min. Samples can be taken from 10°C to 40° C. Minimum recommended sampling time is 7.5 minutes. Maximum recommended sampling time is 8 hours. Storage stability at ambient (25 ° C) or refrigerator (3 ° C) temperatures showed no significant loss in recovery after 21 days. A full validation of Methyl Acrylate was done according to NIOSH Protocol 1 and a partial NIOSH validation by the Bi-level procedure was conducted for MMA and other higher members of this homologous series.

A sampling method for o-chlorostyrene in air has been validated for concentration levels from 0.5 to 120 ppm and for exposure times from 15 minutes to 8 hours. The 575-003 passive sampler used has a sample medium of Anasorb ® 727. Desorption was with carbon disulfide and analysis by gas chromatography with flame ionization detection (GC-FID). The analytical recovery over the range of 0.5 to 120 ppm (16 to 3240 mg) was variable, but >75% for all loadings. A desorption efficiency curve was used to correct results from the other experiments. The sampling rate is 9.8 ml/min. Samples can be taken from 10° C to 40° C. Minimum recommended sampling time is 15 minutes. Maximum recommended sampling time is 8 hours. Samples can be stored for up to 21 days at room temperature or in a refrigerator (4 ° C) without loss of sample. A full validation of styrene was done according to NIOSH protocol 1 and a partial NIOSH validation by the bi-level procedure was conducted for o-chlorostyrene and other higher members of this homologous series.

A sampling method for DIBK in air has been validated for concentration levels from 2.5 to 50 ppm and for exposure times from 30 minutes to 8 hours. The 575-002 passive sampler used has a sample medium of Anasorb ® 747. Desorption was with carbon disulfide and analysis by gas chromatography with flame ionization detection. The analytical recovery over the range of 2.5 to 50 ppm (75-1500 µg) was 98.3% with a relative standard deviation of 4.98%. The sampling rate is 10.3 ml/min. Samples can be taken from 10°C to 40° C.

A sampling method for methyl tert-amyl ether (tert-amyl methyl ether, TAME) in air has been validated for concentration levels from 0.4 to 140 ppm and for exposure times from 30 minutes to 8 hours. The 575-001 passive sampler used has a sample medium of coconut charcoal. Desorption was with carbon disulfide and analysis by gas chromatography with flame ionization detection (GC-FID). The analytical recovery over the range of 4 to 140 ppm (115 to 3820 µg) was 99%. The sampling rate is 13.1 ml/min. Samples can be taken from 10° C to 40° C. Minimum recommended sampling time is 15 minutes. Maximum recommended sampling time is 8 hours. A full validation of methyl tert-butyl ether was done according to NIOSH protocol 1 and a partial NIOSH validation by the bi-level procedure was conducted for TAME and other higher members of this homologous series.