Ozone-scavenging reagents suitable for use in the quantitative determination of aldehydes as the O-(2,3,4,5,6-pentafluorobenzyl) oximes by GC-ECD

Previously, we reported interference due to several ozone-scavenging reagen ts (OSRs) in the quantitation of aldehydes using O-(2,3,4,5,6-pentafluorobe nzyl)oxylamine (PFBOA) in the analysis of ozonated waters. Scavenging ozone is essential if ozonation byproduct concentrations are to be fixed in time , which is required in a study of formation as a function of time; otherwis e, additional redox reactions can rake place prior to analysis. We have sin ce determined that triphenylphosphine and indigo-5,5',7-trisulfonate can be satisfactory OSRs. Both PPh3 and indigo-5,5',7-trisulfonate react rapidly with ozone, i.e., within 10 s. Triphenylphosphine is insoluble in water and must be dissolved in an appropriate organic solvent (e.g., benzene) that c an be dispersed into the sample. When PFBOA is added directly, several minu tes must elapse to completely scavenge the ozone, making this approach unsa tisfactory. Procedures for using these OSRs are described, and quantitative results are explained. Although PPh3 and indigo-5,5',7-trisulfonate produc e deviations relative to controls devoid of OSRs, the biases are precise an d therefore readily corrected for by subjecting calibration standards and a nalyte-fortified (spiked) samples to the same analytical procedure. Publish ed by Elsevier Science Ltd.