Gas chromatography–full scan mass spectrometry determination of traces of chemical warfare agents and their impurities in air samples by inlet based thermal desorption of sorbent tubes

Adsorption and Desorption of Chemical Warfare Agent Simulants on Silica Surfaces with Hydrophobic Coating

“…[5][6][7] Pre-concentrators can include highly efficient adsorbents for CWAs and heating unit. Increasing temperature of the adsorbents will result in desorption of CWAs adsorbed (or accumulated) on adsorbent surface, which can temporarily increase local concentration of CWAs in the pre-concentration-unit, and enhance the detection limit of detector by many orders of magnitude.…”

Measurement of breakthrough volumes of volatile chemical warfare agents on a poly(2,6-diphenylphenylene oxide)-based adsorbent and application to thermal desorption–gas chromatography/mass spectrometric analysis

“…We measured the specific breakthrough volumes and specific elution volumes using an established elution technique [25]. The Tenax ® TA resin was examined first as it is the most commonly used resin for trapping CWAs according to recent reports [21,30]. Taking into consideration the performance of commercial gas sampling pumps, dimensions of popular adsorbent tubes, and on-site countermeasure situations, the flow rate and maximum volume of air sample for analyte trapping were set at 100 mL/min and 5 L, respectively.…”

“…Herein, we investigate the elution behaviors of five CWAs (GB, GD, tabun (GA), VX, and HD) on several resins by monitoring their mass spectrometric response to identify adsorbent resins that are effective in trapping volatile and semi-volatile CWAs (nerve agents and HD) in air samples. The adsorbent resins examined were Tenax ® TA and Tenax ® GR, both of which have been recently used for the analysis of CWAs in air samples [14,15,[19][20][21]23,27]. In addition, the efficiency of Carboxen ® 1016 was also examined.…”

“…On the contrary, semi-volatile CWAs such as VX has a low vapor pressure, potentially causing an insufficient collection of its vapor sample. However, it is important to be able to collect semi-volatile CWA samples, from the ambient atmosphere, in order to analyze them using the highly sensitive GC/MS instruments at off-site laboratories; previous endeavors to address this issue have been reported [14,19,21]. Herein, we investigate the elution behaviors of five CWAs (GB, GD, tabun (GA), VX, and HD) on several resins by monitoring their mass spectrometric response to identify adsorbent resins that are effective in trapping volatile and semi-volatile CWAs (nerve agents and HD) in air samples.…”

“…For the on-site solvent trapping of CWAs, various kinds of adsorbents have been used: Amberlite ® XAD, Chromosorb ® 106, and Tenax ® are recommended for chemical verification and environmental protection purposes [13][14][15], and several methods using these adsorbents for the determination of a wide range of CWAs have been reported [16][17][18][19][20][21]. Amberlite ® XAD resins are hydrophobic cross-linked polystyrene copolymer resins and trapped chemicals can be desorbed from the resins by liquid extraction.…”