GAS-CHROMATOGRAPHIC DETERMINATION OF NITROPHENOLS IN ATMOSPHERIC LIQUID WATER AND AIRBORNE-PARTICULATES

A method for the determination of nitrophenols in fogwater and atmospheric particles is presented. The gas chromatographic (GC) performances of the underivatized pure compounds and their corresponding acetate esters were compared using four fused-silica columns with three alternative detection modes, viz. mass-selective detection, nitrogen-specific detection and electron-capture detection (ECD). Splitless injection of pure nitrophenols suffered from adsorption in the GC system causing unacceptable imprecision in the quantification of semi-volatile nitrophenols. The separation of nitrophenols as their corresponding acetates and ECD improved the GC performance and the analytical results. Acetylation with acetic anhydride in alkaline aqueous solution was found to be a very specific, uncomplicated and rapid method of derivatization. Its high sensitivity and accuracy and excellent suitability for analysing complex aqueous samples such as fogwater is demonstrated in detail as part of a multi-residue procedure.