MEASUREMENT OF SUB-PARTS-PER-BILLION LEVELS OF CARBONYL-COMPOUNDS IN MARINE AIR BY A SIMPLE CARTRIDGE TRAPPING PROCEDURE FOLLOWED BY LIQUID-CHROMATOGRAPHY

Carbonyl compounds in clean marine air were trapped onto 2, 4-dinitrophenylhydrazine-(DNPH-) coated cartridges, and their hydrazone derivatives were separated by HPLC and detected by UV absorbance. More than 20 carbonyl compounds were isolated from marine air with >92% collection efficiency. The technique employs a highly effective reagent purification procedure, which results in much lower blanks compared to previously reported trapping techniques for carbonyl compounds. Blanks were routinely <0.07 ppb for formaldehyde and acetone and <0.02 ppb for the others. Humidity and reactive gases have no detectable effect on collection efficiencies. Carbonyl-DNPH derivatives eluted from the cartridges are stable in acetonitrile for at least 2 weeks, which facilitates field studies. Several previously undetected unknown carbonyl compounds were found in marine air by this technique. Typical results for open ocean and coastal marine air are shown. © 1990, American Chemical Society. All rights reserved.