GC/ITMS measurement of carbonyls anti multifunctional carbonyls in PM2.5 particles emitted from motor vehicles

A method was developed and tested to identify and quantitate carbonyls and multifunctional carbonyls in fine particulate matter (PM2.5; <2.5 mum aerod ynamic diameter). The method relies on ultrasonic extraction of particulate matter on filters at -8 degreesC; derivatization with O-(2,3,4,5,6-pentafl uorobenzyl) hydroxylamine (PFBHA), and PFBHA along with bis (trimethylsilyl ) trifluoroacetamide (BSTFA); and detection of the derivatives by gas chrom atography/ion trap mass spectrometry. Ultrasonic extraction of model compou nds from enriched particles was affected by solvent polarity (water > methy lene chloride > toluene-isopropanol (2 + 1, v/v). Water provided the highes t recovery for dihydroxy acetone, pyruvic acid, and hydroxy acetone, compar ed to methylene chloride, and toluene-isopropanol. Lowering the ultrasonica tion bath temperature from 0 degrees to -8 degreesC improved the recoveries of the less water soluble and more volatile species-methacrolein, methyl v inyl ketone, 2,3-butanedione, and tolualdehyde. The power of the method was demonstrated by identification and quantitation of carbonyls and multifunc tional carbonyls in sample extracts of fine particulate matter (PM2.5) coll ected in the Caldecott tunnel, CA. The identities of crotonaldehyde, 2,3-bu tanedione, glyoxal, 9H-fluoren-9-one, glycolaldehyde, glyoxylic acid, levul inic acid, and 3-hydroxybenzaldehyde were confirmed by comparing the relati ve retention time and mass spectra of the analyte in the sample extract wit h an authentic standard. Quantitation of crotonaldehyde, glyoxal, 2,3-butan edione, glyoxylic acid, and levulinic acid was accomplished. This is the fi rst report of glyoxylic acid, levulinic acid, and 3-hydroxybenzaldheyde in PM2.5 particles sampled in a roadway tunnel. It is also the first report of a Clo carbonyl with the molecular formula of C10H16O2, a hydroxy carbonyl with the molecular formula of C17H21NO2, and a hydroxy or dihydroxy carbony l with the molecular formula of C16H14O2 or C9H10O3 The high-molecular weig ht hydroxy carbonyls, which were found only in the heavy-duty (diesel) bore , may be tracers of diesel emissions in air.