ANALYTICAL RELIABILITY OF CARBONYL COMPOUND DETERMINATION USING 1,5-DANSYLHYDRAZINE-DERIVATIZATION

Solid sorbents coated with the fluorescent reagent 5-dimethylaminonaph thalene-1-sulfohydrazide (dansylhydrazine, DNSH) have been used for de rivatization and quantitative determination of airborne carbonyl compo unds, for example in investigations on atmospheric pollution. The eval uation of this derivatization reaction presented here revealed that, f or several reasons, it may not be recommended when sampling is perform ed with impingers containing liquid reagent solutions. Derivative yiel ds came out to be strongly influenced by water and phosphoric acid whi ch are essential for sufficient derivatization rates, but also respons ible for the degradation of derivatives. Even at water and acid concen trations considered as an optimal compromise between accelerating and degrading effects, the analytical reliability of the method can only b e guaranteed under controlled laboratory conditions. The reduced or la cking reactivity of DNSH towards aromatic aldehydes or aliphatic and a romatic ketones is an additional finding discarding the DNSH method fo r routine air monitoring at least when impingers are used for sampling .