title: Optimisation of the selectivity of a pulsed flame photometric detector for unknown compound screening.
abstract: Identification of traces of chemical warfare agents (CWA) is generally performed with spectral methods such as mass spectrometry (MS) or NMR, but the use of element-specific detectors is most often required to extract interesting signals from gas chromatographic (GC) data heavily masked by natural interferents. The pulsed flame phosphorus detector (P-FPD) is able to detect phosphorus, sulphur and arsenic, and thus should be very well-suited to CWA detection. However, first results using standard operating conditions recommended by the manufacturer of P-FPD led to false positive detection of phosphorus-containing compounds on the sulphur line. Therefore, an optimisation process of the selectivity of P-FPD for phosphorus versus sulphur or arsenic was undertaken, and allowed to identify gate delay and gate width as crucial parameters for the performance of P-FPD. While selectivity could be significantly improved, unexpectedly, this resulted in a concurrent important loss of sensitivity (ca. 45%) for arsenic, which suggests that this detector should be carefully optimised with respect, and prior to its purported use.
authors.affiliation: Section Analyse Chimique, Centre d'Etudes du Bouchet, BP3, 91710 Vert-le-Petit, France.
authors.forename: Jean-Pierre
authors.initials: JP
authors.lastname: Le Harle
authors.forename: Bruno
authors.initials: B
authors.lastname: Bellier
mesh_terms: D001151:Arsenic / Q000032:analysis; D002849:Chromatography, Gas / Q000295:instrumentation; D010758:Phosphorus / Q000032:analysis; D012680:Sensitivity and Specificity; D013053:Spectrophotometry / Q000295:instrumentation*; D013455:Sulfur / Q000032:analysis
chemical_list: D010758:Phosphorus; D013455:Sulfur; D001151:Arsenic