Measurement of hydroxy carbonyls and other carbonyls in ambient air using pentafluorobenzyl alcohol as a chemical ionization reagent

Hydroxy carbonyls and other carbonyls were measured in air by sampling with impingers filled with an aqueous solution of O-(2,3,4,5,6-pentafluorobenzy l)hydroxy hydrochloride (PFBHA), further reacting the PFBHA derivatives of hydroxy carbonyls with bis(trimethylsilyl)trifluoroacetamide (BSTFA), and d etecting the derivatives with gas chromatography/ion trap mass spectrometry . Molecular weight determinations of ultratrace (pptv) levels of the deriva tives in the presence of coeluting interferences was made possible by using pentafluorobenzyl alcohol (PFBOH) as a chemical ionization reagent. Methyl vinyl ketone, methacrolein, methylglyoxal, glycolaldehyde, and hydroxyacet one were identified in air collected in Azusa, CA, Methyl vinyl ketone, met hacrolein, methyl-glyoxal, hydroxyacetone, glyoxal, and 3-hydroxy-2-butanon e were identified in samples collected in Davis, CA. To our knowledge, this is the first report of hydroxyacetone and 3-hydroxy-2-butanone in the ambi ent atmosphere. This work is a significant contribution to the measurement of hydroxy carbonyls in air. It demonstrates the potential of the method to measure water-soluble carbonyls for which no or little ambient air data ex ist. It is also the first study that applies pentafluorobenzyl derivatizati on along with ion trap mass spectrometry to measure carbonyls in the ambien t atmospheric environment.