Cryogenic preconcentration

Collected in stainless steel canister preconcentrated by cryogenic trapping thermally desorbed... 

EPA. 1988g. Method T03. Method for the determination of volatile organic compounds in ambient air using cryogenic preconcentration techniques and GC with flame ionization and electron capture detection. Compendium of methods for the determination of toxic organic compounds in ambient air. Atmospheric Research and Exposure Assessment Laboratory, Office of Research and Development, U.S. Environmental Protection Agency, RTP, NC. EPA/600/4-89/017. 

Rhoderick GC, Miller WR. 1990. Multipoint calibration of a gas chromatograph using cryogenic preconcentration of a single gas standard containing volatile organic compounds. Anal Chem 62 810-815. 

Koppmann, R., F. J. Johnen, A. Khedim, J. Rudolph, A. Wedel, and B. Wiards, The Influence of Ozone on Light Nonmethane Hydrocarbons during Cryogenic Preconcentration, J. Geophys. Res., 100, 11383-11391 (1995). 

McElroy, F. F., V. L. Thompson, D. M. Holland, W. A. Lonneman, and R. L. Sella, Cryogenic Preconcentration-Direct FID Method for Measurement of Ambient NMOC Refinement and Comparison with GC Speciation, JAPCA, 36, 710-714 (1986). 

TO-12 Cryogenic preconcentration and direct flame ionization detection Nonmethane organic compounds... 

Air (methyl, dimethyl mercury) Preconcentration of sample onto graphitized carbon substrate separation by cryogenic gas chromatography GC/CVAFS 0.3 pg (mercury, dimethyl mercury) 0.4 pg (diethyl mercury) 2 pg (methyl mercury chloride) 91-105 Bloom and Fitzgerald 1988... 

Foss G. O., Svec H. J. and Conzemius R. J. (1983) The determination of trace elements in aqueous media without preconcentration using a cryogenic hollow-cathode ion source, Anal Chirn Ada 147 151-162. 

Cryogenic preconcentration of sample (catalytic fluorination after GC to form SFb) GC/ECD 6.25 ng/m3 NR Johnson and Bates 1993... 

Prepare with isotopically labelled internal standard (ILS) cryogenic preconcentration GC/MS 0.625 ng/m3 NR... 

FIGURE 16.1 Cryogenic preconcentration/high-resolution gas chromatographic system for the analysis of whole-air samples collected in canisters. 

Volatile analytes cryogenically preconcentrated at —78°C on the U trap species identified by retention time matching, elemental isotopic fingerprints, and ion trap MSn analysis Batch HG to generate hydride derivatives cryogenic preconcentration at — 196°C on the U-trap thermally desorbed into an ICP-MS identification of species based on comparison with standards or calculation of boiling point... 

Breath samples have been analyzed for tetrachloroethylene in several studies. Preconcentration on a solid sorbent followed by thermal desorption onto a cryogenic trap connected to the gas chromatograph was used to analyze exhaled air in several TEAM studies (Wallace 1986 Wallace et al. 1986a, 1986b, 1986c, 1986d). Vapors were thermally released directly onto the chromatographic column for separation and detection by electron impact MS (EIMS). 

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