气相色谱-脉冲放电氦离子化检测器法同时测定乙烯或丙烯中5种无机气体

Simultaneous Determination of 5 Inorganic Gases in Ethylene or Propylene by GC with Pulsed Discharge Helium Ionization Detector

用带脉冲放电氦离子化检测器的气相色谱法同时测定乙烯或丙烯中氢气、氧气、二氧化碳、一氧化碳和氮气等5种无机气体的含量。充分气化的样品注入色谱仪,借助仪器的高度集约化操作程序及阀系统切换功能,样品流经2根微填充色谱柱,先后使氢气、氧气、二氧化碳、一氧化碳和氮气等5种气体得到分离和测定。这5种气体的体积分数均在0.50~10.0mL·m^-3内与其对应的峰面积呈线性关系,上述5种气体的检出限(3S/N)依次为0.02,0.01,0.02,0.03,0.01mL·m^-3。对一组5种气体的混合标准气体进行8次重复测定,其保留时间的相对标准偏差在0.040%~0.15%之间,其峰面积的相对标准偏差在0.98%~2.3%之间,证明此方法同时测定5种气体的重复性良好。对另一组5种气体的混合标准气体进行6次平行测定,测定值与已知值相符,测定值的相对标准偏差(n=6)均小于1.0%。

GC with pulsed discharge helium ionization detector was applied to the simultaneous determination of 5 inorganic gases,i.e.H2,O2,CO2,CO and N2 in ethylene or propylene.The fully gasified sample was introduced into the chromatograph.With the help of the highly intensive operational program of the instrument and the switching function of the valve system,the 5 gases,i.e.H2,O2,CO2,CO and N2 were separated and determined successively during passing of the sample through 2 packed micro-chromatographic columns.Linear relationships between values of peak area and volume fraction of the 5 gases were found in the same range of 0.50 to10.0 mL·m^-3,with detection limits(3 S/N)of 0.02,0.01,0.02,0.03,0.01 mL·m^-3 respectively.A set of standard gas mixture of the 5 gases was analyzed by the proposed method for 8 repeated determinations,giving values of RSDs for retention time in the range of 0.040%to 0.15%,and RSDs for peak area in the range of 0.98%to 2.3%,and showing good repeatability of the method in simultaneous determination of the 5 gases.Another set of standard gas mixture of the 5 gases was analyzed in parallel for 6 times,giving results in consistency with the known values,and RSDs(n=6)of determination values all less than 1.0%.