Pentafluorophenylhydrazine as Coating Reagent for the HRGC_MS Determination of Semi-Volatile Carbonyl Compounds in Air

Sensitive detection of semi-volatile carbonyl compounds in air can be achieved by using pentafluorophenylhydrazine-coated (PFPH) silica cartridges. Hydrazones formed during sampling are extracted with dichloromethane-acetonitrile and analysed by GC-MS operated in selected-ion-monitoring mode (SIM). The low detection limits reached (20 ppt (v/v) for sampling periods of 1 h) makes this method a valid alternative to other HPLC-UV and HRGC_MS techniques recently developed. Several experimental variables, for example collection and derivatization efficienty, interference by ozone, and storage stability of blank and sampled cartridges, have been investigated. Comparison field tests with the classical dinitrophenylhydrazine (DNPH) method showed results to be very consistentfor C4-C11 n-alkanals and 6-h sampling periods during which six PFPH cartridges were run in parallel (each for 1h)with one 2,4-dinitrophenylhydrazine(DNPH)-coated cartridge.