(60 m 0.32 mm 1.0 lm) with three programmed temperatureranges as following: ramp from 35 C to 150 C at a rate of5 C min 1; from 150 C to 220 C at a rate of 15 C min 1; and holdfor 7 min at 220 C. The mass spectrometer was operated in fullscan, in the m/z range of 15–300. The mass spectrometer was usedin electron impact ionization mode at 70 eV. Volatile organic compoundsin the air sample were identified by comparing their retentiontimes with the standards, and identified compounds werequantified by using the internal standard method.