DETERMINATION OF FORMALDEHYDE AND ACETALDEHYDE ASSOCIATED TO ATMOSPHERIC AEROSOLS BY HPLC

A rapid new analytical protocol was developed for the determination of formaldehyde and acetaldehyde associated to atmospheric particulate matter, at ng/m3 levels. The aerosols were collected on glass fiber filters (8'' x 10'') at face velocities ranging from 15 m/min to 23 m/min. Aliquots of 15.4 cm2 were sonicated, for 20 min, with 5.0 mL of 0,01% 2,4-dinitrophenylhydrazine (DNPH), 1% phosphoric acid. The liquid phase was then filtered and the separation and quantification of the corresponding 2,4-dinitrophenylhidrazone (DNPHo) derivatives carried out by reverse phase HPLC. Acetonitrile:water (57:43, v/v) as mobile phase at 1.0 mL/min and absorbance detection at 350 nm and 365 nm for, respectively, formaldehyde-DNPHo (0.04 AUFS) and acetaldehyde-DNPHo (0.01 AUFS) were used. The precision for four different aliquots, from a 8'' x 10'' glass fiber filter, were under 0.04% for formaldehyde and 14.16% for acetaldehyde. In Salvador, Bahia, Brazil, formaldehyde and acetaldehyde were determined, respectively, in the range of 6.8 ng/m3 to 27.3 ng/m3 and 9.1 ng/m3 to 54.6 ng/m3.