基于GC-FID分析方法的VOCs自动监测仪测试研究

Study on VOCs Automatic Monitor based on GC-FID

在保证自动监测仪进样流量恒定和相同校准标准物质的情况下,采用标准气体对某排污单位无组织厂界基于GC-FID分析方法的VOCs自动监测仪的非甲烷总烃和苯系物(苯、甲苯、二甲苯)的精密度和线性误差进行分析测试,非甲烷总烃的重复性能控制在±3%以内,苯系物的重复性能控制在±5%以内,线性误差均能控制在±10%以内,低浓度的苯系物绝对误差控制在±0.5 mg/m^3以内。实际样品比对时,采用玻璃注射器和PVF采样气袋与自动监测仪同时采集样品比对测试,玻璃注射器本底低于采样气袋,测试结果优于气袋采样结果,非甲烷总烃和苯系物的绝对误差均能控制在±0.5 mg/m^3以内。

In the case of constant flow and the sane calibration standard material ,according to the test result of VOCs automatic monitor based on GC-FID installed on the boundary of one pollution discharge company, the repeatability of Non- methane Hydrocarbons can be less than or equal to three percent and the repeatability of Benzene series（benzene, toluene, xylene） can be less than or equal to five percent. The linearity error of Non-methane Hydrocarbons and Benzene series can be both less than or equal to ten percent. The low concentration of Benzene series can be less than or equal to 0.5 mg/m3. Took sample by glass syringe or PVF air pocket, the absolute error of VOCs automatic monitor with by glass syringe is better than by PVF air pocket. The background of glass syringe is lower than PVF air pocket. The absolute error of Non-methane Hydrocarbons and Benzene series are both less than 0.5 mg/m3.