Continuous monitoring of chemical warfare agents in vapor using a Fourier transform infra-red spectroscopy instrument with multi pass gas cell, mercury cadmium telluride detector and rolling background algorithm

Detection of gaseous nerve agent simulants with broadband photoacoustic spectroscopy

“…The observed variations result from measurement errors and various parameters affecting the adsorption process such as polarity and molecular weight (Li et al, 2020). Lower sampling efficiencies of about 10% have been reported for a conventional FTIR system (Ohrui et al, 2020), most likely caused by the significantly larger volume of the gas equipment. The uncertainties in the calibrated simulant concentrations shown in the rightmost column of Table 1 include errors in the calibration constant A (0.5% from the fitting, 3.1% from optical power (Mikkonen et al, 2022b), and 5% from the absorption cross section of CH 4 (Daumont et al, 2013)), absorption cross sections of simulants (6.2-12% (Neupane et al, 2019)) and optical power again (3.1% (Mikkonen et al, 2022b)).…”

“…The simplest detectors such as electrochemical (Liu and Lin, 2005), colorimetric (Davidson et al, 2020) and fluorimetric sensors (Khan et al, 2018;Meng et al, 2021), surface acoustic wave detectors (Kim et al, 2020) and ion-mobility spectrometers (Puton and Namieśnik, 2016) provide a low-cost option for screening, but they suffer from poor sensitivity, insufficient selectivity and/or susceptibility to changes in temperature and humidity. Technologies with improved performance include gas chromatography mass spectrometry (Smith et al, 2004), Raman spectroscopy (Lafuente et al, 2020) and infrared absorption spectroscopy (Pushkarsky et al, 2006;Mukherjee et al, 2008;Gurton et al, 2012;Levy, 2009;Sharpe et al, 2003;Ruiz-Pesante et al, 2007;Ohrui et al, 2020;Melkonian et al, 2020), which are preferred in different scenarios due to their specific characteristics. Infrared absorption spectroscopy is typically well suited for rapid identification of volatile NAs in ambient air, techniques ranging from extremely sensitive photoacoustic spectroscopy (PAS) (Pushkarsky et al, 2006;Mukherjee et al, 2008;Gurton et al, 2012) to Fourier transform infrared spectroscopy (FTIR) (Sharpe et al, 2003;Ruiz-Pesante et al, 2007;Ohrui et al, 2020) capable of selective multi-species detection.…”

“…Technologies with improved performance include gas chromatography mass spectrometry (Smith et al, 2004), Raman spectroscopy (Lafuente et al, 2020) and infrared absorption spectroscopy (Pushkarsky et al, 2006;Mukherjee et al, 2008;Gurton et al, 2012;Levy, 2009;Sharpe et al, 2003;Ruiz-Pesante et al, 2007;Ohrui et al, 2020;Melkonian et al, 2020), which are preferred in different scenarios due to their specific characteristics. Infrared absorption spectroscopy is typically well suited for rapid identification of volatile NAs in ambient air, techniques ranging from extremely sensitive photoacoustic spectroscopy (PAS) (Pushkarsky et al, 2006;Mukherjee et al, 2008;Gurton et al, 2012) to Fourier transform infrared spectroscopy (FTIR) (Sharpe et al, 2003;Ruiz-Pesante et al, 2007;Ohrui et al, 2020) capable of selective multi-species detection.…”

Innovative Vibrational Spectroscopy Research for Forensic Application

“…Ohrui et al conducted research on the monitoring of CWAs in a vapor utilizing FTIR spectroscopy with a multipass gas cell, a mercury cadmium telluride detector, and a rolling background algorithm. 163 Sarin vapors, a nerve agent, were prepared in ambient air and analyzed. Characteristic bands were absorbed in the fingerprint region (700−1400 cm −1 ) and 2950 cm −1 .…”

“…Therefore, significant research has gone into the ability to detect vaporous CWAs rapidly and safely. Ohrui et al conducted research on the monitoring of CWAs in a vapor utilizing FTIR spectroscopy with a multipass gas cell, a mercury cadmium telluride detector, and a rolling background algorithm . Sarin vapors, a nerve agent, were prepared in ambient air and analyzed.…”