Based on portable gas chromatography-mass spectrometry(GC-MS)coupled with sorbent adsorption and thermal desorption,a method was developed for the analysis of ambient air volatile organic compounds(VOCs).Then the linearity,repeatability and accuracy of the method were investigated.The results show that the method is capable for the quantitative analysis of 54 VOCs,including C3—C12 n-alkanes,iso-alkanes,olefins,cycloalkanes,and benzene series.The identification of individual compounds can be achieved by the gas chromatographic retention time and mass spectra comparison.Calibration curve correlation coefficients exceeded 0.99;the relative standard deviations(RSD)after repeated determination ranged from 0.4％to 8.2％,and the accuracy distribution fell within the range of 71％to 101％;the detection limits of propane and propylene were 10 nmol/mol,while the detection limits of C4—C12 volatile organic compounds were 1 to 5 nmol/mol.The total time of sample collection and analysis can be controlled within 30 minutes.The established method fulfills the requirements for daily monitoring,early warning and emergency investigation in refining and chemical sites.The results obtained from representative samples collected at various refinery sites show significant variations in composition and concentration of compounds,indicating the capability of this method to establish a comprehensive database for monitoring VOCs in ambient air and establishing a chemical characteristic profile database for emission source in subsequent stages.
volatile organic compounds(VOCs)ambient airrefinery siteportable gas chromatography-mass spectrometry method
万方数据
维普
