Abstract: Objective To establish a portable gas chromatography-mass spectrometry method for the determination of methyl methacrylate in workplace air. Methods The sample was directly introduced by a portable gas chromatography-mass spectrometer or adsorbed by a Tenax GR adsorption tube and then thermally desorbed. After separation by gas chromatography,it was detected by a 3D ion trap mass spectrometry detector. Qualitative analysis was performed by retention time and characteristic ions,and quantitative analysis was performed by the internal standard method. Results When using the direct introduction with quantitative loop injection method,the linear range was 56.16-224.64 mg/m³,the correlation coefficient was 1.000,the detection limit was 0.314 mg/m³,and the lower limit of quantification was 1.0 mg/m³. The accuracy was （99±3）%-（100±4）%,the intra-batch relative standard deviation was 3.17%-5.03%,and the inter-batch relative standard deviation was 4.55%-6.93%. When using the adsorption tube injection method,the linear range was 0.94-56.16mg/m³,the correlation coefficient was 1.000,the detection limit was 0.117 mg/m³,and the lower limit of quantification was 0.390 mg/m³. The accuracy was （97±7）%-（109±10）%,the intra-batch relative standard deviation was 5.66%-9.21%,and the inter-batch relative standard deviation was 7.73%-11.24%. Conclusion This method adopts the internal standard method,which is rapid,sensitive,and accurate,suitable for on-site rapid detection and real-time monitoring of methyl methacrylate in workplace air. The determined results can be applied to the assessment and classification control of occupational exposure levels.

Key words: Workplace, Air, Internal standard method, Methyl methacrylate, Portable gas chromatography-mass spectrometry