工作场所空气中硝基苯浓度的便携式气质联用快速检测法

Rapid determination of nitrobenzene concentration in workplace air by portable GC-MS

目的建立作业场所空气中硝基苯的快速定性、定量的便携式气质联用的检测方法。方法使用静态配气法配制一定浓度的硝基苯标准气,在实验室建立硝基苯浓度的回归方程,然后在工作场所使用便携式气质联用仪直接采样,对空气中硝基苯进行浓度定量与定性识别,同时使用国家标准方法对空气中的硝基苯浓度进行实验室分析,比较不同方法的检测结果,以确认所建立方法的准确度。结果空气中硝基苯浓度在0.753~30.120 mg/m^3时具有很好的线性;回归方程为Y=6×10^(-8)X+0.095 1,r=0.998;检出限0.038 mg/m^3;定量下限0.376 mg/m^3。高、中、低3个浓度下的精密度(RSD)在0.3%~4.7%之间;批间精密度(RSD)在2.5%~7.3%之间,测量准确度在102.1%~114.3%之间;与国家标准检测方法比较,GC-MS结果在标准方法结果的75.0%~94.3%之间。空气中苯、甲苯、苯乙烯等物质对测定不产生干扰。结论便携式GC-MS能直接检测空气中硝基苯浓度,方法准确、简便、快速,能反映空气中硝基苯的真实浓度,结果与实验室标准方法检测结果差异无统计学意义,适合于工作场所空气中硝基苯浓度的检测。

[Objective]To establish a rapid qualitative and quantitative method for the determination of nitrobenzene concentration in workplace air by portable GC-MS.[Methods]The nitrobenzene standard gas at a certain concentration was prepared by the static method,and the regression equation of nitrobenzene concentration was established in the laboratory. The samples were directly collected in workplace by portable GC-MS device,to perform the quantitative and qualitative identification on the nitrobenzene concentration in air. At the same time,the nitrobenzene concentration in air was analyzed by the national standard method,and the results of different methods were compared to confirm the accuracy of the established method.[Results] The method showed good linearity within the nitrobenzene concentrations of 0. 753-30. 120 mg/m^3. The regression equation was Y = 6 × 10^（-8）X＋0.095 1,r=0.998. The detection limit was 0.038 mg/m^3,and the lower limit of quantification was 0.376 mg/m^3. The precisions（RSD） of spiked samples were between 0.3% and 4.7%,the between-run precisions（RSD） were between 2.5% and7.3%,and the measurement accuracy was 102.1%-114.3%. Compared with the national standard method,the results of GC-MS were at 75.0%-94.3% of the results by the national standard method. Benzene,toluene,styrene and other substances in the air did not interfere with the determination.[Conclusion] The portable GC-MS can detect the concentration of nitrobenzene in air directly,which is accurate,simple and rapid,and can reflect the true concentration of nitrobenzene in the air. There is no statistically significant difference in results between this method and standard laboratory method. The method is suitable for detecting the concentration of nitrobenzene in the air of workplace.