Simple device for permeation removal of water vapour from purge gases in the determination of volatile organic compounds in aqueous samples

Suitability of different polymer bags for storage of volatile sulphur compounds relevant to breath analysis

“…Tedlar [27,28,34]) and some analytical problems during the gas chromatographic analysis of VSCs in humidified samples. The most commonly reported humidity effects are: decrease of the adsorption capacity of the sorbents, plugging of cold traps at sub-zero temperatures and retention time variations in the case of the sorbent trapping [21,38,39], and decrease of the extraction efficiency in the SPME [35]. The last effect was also observed during our studies and was particularly severe for H 2 S, COS, MeSH and EtSH (80% efficiency drop) [41].…”

“…The last effect was also observed during our studies and was particularly severe for H 2 S, COS, MeSH and EtSH (80% efficiency drop) [41]. Consequently, sample drying prior to the extraction in GC analysis is recommended [21,39].…”

GeoVOC: A SIFT-MS method for the analysis of small linear hydrocarbons of relevance to oil exploration

“…Nafion TM tubing is a co-polymer of teflon and perfluoro-3,6-dioxa-4-methyl-7-octene-sulfonic acid, which is unreactive to non-polar compounds such as hydrocarbons, but reactively diffuses polar water molecules across a concentration gradient. By flowing dry nitrogen over the outer surface of the Nafion TM tubing, water molecules diffuse across the concentration gradient from the moist sample into the nitrogen purge flow, while leaving hydrocarbon concentrations unaltered [20].…”

On-line monitoring trihalomethanes in chlorinated water by membrane introduction–fast gas chromatography mass–spectrometry

“…The injection also cross the membrane [7,18]. The presence of sulting from water was observed and this peak water can cause many problems [18][19][20] and several overlapped with the peaks of dibromochloromethane procedures have been proposed to avoid the effects and bromoform if the concentrations of THMs were of water [19,[21][22][23]. Initially, to remove moisture in the low ppb or ppt range.…”