title: Determination of airborne carbonyls via pentafluorophenylhydrazine derivatisation by GC-MS and its comparison with HPLC method.
abstract: The classical analytical method for gaseous carbonyl measurements based on solid sorbent coated with 2,4-dinitrophenylhydrazine (DNPH) and analysis by HPLC/UV suffers from limited resolution of carbonyls with similar molecular structures and high molecular weights. In this paper, we report the development of a sensitive and reliable analytical method for simultaneous determination of 21 airborne carbonyls within the C(1)-C(9) range. Carbonyls were collected on a sampling tube filled with 100mg Tenax TA (60-80 mesh) sorbent coated with 1 μmol pentafluorophenyl hydrazine (PFPH), followed by solvent desorption and analysis by gas chromatography (GC)/mass spectrometry (MS). Common carbonyl gases including formaldehyde, acetaldehyde, butyraldehyde, hexaldehyde and benzaldehyde at ppbv levels were collected with efficiency greater than 90% onto sampling tubes at a flow rate of 100 mL min(-1). The limits of detection (LODs, signal/noise=3) of the tested carbonyls were in the range of 0.08-0.20 ppbv for a sampled volume of 24.0 L. These limits are less than or comparable with those that can be obtained using the DNPH-HPLC method. The method has been field-tested both in ambient air of York and in diluted cigarette smoke. Comparing field tests with the classical DNPH-HPLC method, good agreement was displayed between the two methods for the same carbonyls, but with more carbonyl species detected by the PFPH-GC/MS method. The PFPH-GC/MS method provides better molecular separation for carbonyls with similar structures, is highly sensitivity and gives confirmation of identification by structures when detected using MS.
authors.affiliation: Department of Chemistry, University of York, Heslington, York YO10 5DD, UK. pangxbyuanj@gmail.com
authors.forename: Xiaobing
authors.initials: X
authors.lastname: Pang
authors.forename: Alastair C
authors.initials: AC
authors.lastname: Lewis
authors.forename: Jacqueline F
authors.initials: JF
authors.lastname: Hamilton
mesh_terms: D000447:Aldehydes / Q000032:analysis*; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods*; D005740:Gases / Q000032:analysis*; D006834:Hydrazines; D057230:Limit of Detection; D005464:Fluorobenzenes; D005466:Fluorocarbons
chemical_list: D000447:Aldehydes; D005740:Gases; D006834:Hydrazines; C031120:(pentafluorophenyl)hydrazine; D005464:Fluorobenzenes; D005466:Fluorocarbons