A method for the airborne measurement of PAN, PPN, and MPAN

Abstract

Abstract. An aircraft-based instrument for the measurement of peroxyacetic nitric anhydride (PAN) and related compounds peroxypropionic nitric anhydride (PPN), and peroxymethacrylic nitric anhydride (MPAN) is described. The instrument functions by direct injection of a small sample (2 ambient cm3) into a wide bore fused silica capillary gas chromatographic separation column with subsequent detection by electron capture. The efficiency of separation and early elution of water made possible a sampling frequency of once every 5 min. The selective destruction of PAN type compounds at 125øC in actual ambient samples showed that no interfering species were present. Calibration of the instrument was accomplished by the total oddnitrogen (NOy) measurement of air mixtures of high-purity PANs. Inflight calibrations of PAN in either thermally decomposed ambient air or dry zero air showed that the sensitivity of the instrument to PAN was not affected by other matrix species such as carbon dioxide or water. The instrument response to PPN and MPAN relative to that of PAN was consistent (within 5%) over the span of several months. The instrument response to PAN was linear up to 3.5 ppbv and the slope of the response versus [PAN] indicated a relative standard deviation of 2% over the course of a 30-day field study. The detection limits of the method for PAN and PPN were estimated to be 5 pptv (3s) based on the uncertainty of peak detection. The overall accuracy of the PAN measurement was estimated to be +_(5 pptv+15%) in one campaign and +_(5 pptv+20%) in others.

A gas chromatograph for quantification of peroxycarboxylic nitric anhydrides calibrated by thermal dissociation cavity ring-down spectroscopy

“…Roberts (personal communication, 2009) that are based on those described in earlier publications (Williams et al, 2000;Bertman and Roberts, 1991). Reagents were purchased from Sigma-Aldrich and used as received.…”

“…A widely used, mature, robust, and sensitive technique is gas chromatography with capillary columns and electron capture detection (e.g., Darley et al, 1963;Blanchard et al, 1990;Schrimpf et al, 1995;Williams et al, 2000;VolzThomas et al, 2002;Flocke et al, 2005); this measurement technique is referred to as PAN-GC in this manuscript. A relatively new and increasingly popular technique is thermal dissociation chemical ionization mass spectrometry (TD-CIMS).…”

An aircraft-borne chemical ionization – ion trap mass spectrometer (CI-ITMS) for fast PAN and PPN measurements

“…The best established technique for measurements of PAN and its homologues is gas chromatography with an electron capture detector (GC-ECD), which benefits from good characterisation and provides low detection limits of a few pmol mol −1 (Singh and Salas, 1983;Williams et al, 2000; Published by Copernicus Publications on behalf of the European Geosciences Union.…”

Development of a photochemical source for the production and calibration of acyl peroxynitrate compounds

“…The oldest and most widely used of these techniques is gas chromatography (GC) coupled to a detection method such as (i) electron capture (Darley et al, 1963;Williams et al, 2000;Flocke et al, 2005;Schrimpf et al, 1995;Roberts et al, 2006;Roberts, 1990), (ii) chemiluminescence (Gaffney et al, 1998), or (iii) mass spectrometry (Tanimoto et al, 1999). Liquid chromatography has also been used for the measurement of PAN, with limited results (Grosjean et al, 1991).…”