Volatile fatty acids(VFAs) are typical malodorous substances
which are at trace levels in the ambient air.A method of gas chromatography-mass spectrometry(GC-MS) was established for the simultaneous determination of seven VFAs ie.acetic acid
propanoic acid
isobutyric acid
butyric acid
acrylic acid
isovaleric acid and valeric acid in ambient air.Ambient air samples were firstly collected with impregnated silica gel tube
then ultrasonically extracted with ultrapure water
finally partitioned with methyl tert-butyl ether
concentrated and set to a certain volume.The target compounds were determined by GC-MS
and quantified by internal standard method.Results showed that the calibration curves for seven VFAs were linear(r2≥0.995) in their respective concentration ranges with the detection limits of 0.11-4.78 μg/m3.The recoveries were in the range of 62.3%-110% with relative standard deviations of 2.2%-12%.The method is simple
accurate and sensitive
and is suitable for the determination of VFAs in ambient air.