气相色谱-氮化学发光检测器法测定高纯丁二烯中乙腈的含量

Determination of Acetonitrile in High Purity Butadiene by Gas Chromatography with Nitrogen Chemiluminescence Detector

通过优化色谱条件,消除了烃类组分对乙腈的干扰,提出了气相色谱-氮化学发光检测器法测定高纯丁二烯中乙腈含量的方法。优化的色谱条件如下:HP-1石英毛细管色谱柱(30 m×0.32 mm,3.0μm);载气为氦气,柱流量12.0 m L·min^(-1);分流进样,分流比5∶1;进样量2 m L;初始柱温40℃,保持3 min,以50℃·min^(-1)的速率升温至200℃,保持2 min。按照色谱条件对样品直接进行测定,外标法定量。结果表明:乙腈的质量分数在0.10~10.00 mg·kg^(-1)内与对应的峰面积呈线性关系,检出限为0.024 9 mg·kg^(-1);对空白样品进行3个浓度水平的加标回收试验,回收率为101%~108%,测定值的相对标准偏差(RSD,n=12)均小于6.0%;方法用于10批实际样品分析,测定值的RSD(n=6)均小于6.0%。

By optimizing chromatographic conditions,the interference of hydrocarbon components on acetonitrile was eliminated.A method for determination of acetonitrile in high purity butadiene by gas chromatography with nitrogen chemiluminescence detector was proposed.The optimized chromatographic conditions were as follows:HP-1 quartz capillary chromatographic column(30 m×0.32 mm,3.0μm);helium as carrier gas,at column flow rate of 12.0 mL·min-1;split injection at split ratio of 5∶1;injection volume of 2 mL;initial column temperature of 40℃,which was maintained for 3 min,and raised to 200℃at rate of 50℃·min-1 for 2 min.The sample was directly determined according to chromatographic conditions,and external standard method was used for quantification.It was shown that linear relationship between the corresponding peak areas and mass fractions of acetonitrile was found in the range of 0.10-10.00 mg·kg-1,with detection limit of 0.0249 mg·kg-1.Test for recovery was made on the blank sample at 3 concentration levels,giving results in the range of 101%-108%,with RSDs(n=12)of the determined values less than 6.0%.The method was applied to the analysis of 10 batches of actual samples,with RSDs(n=6)of the determined values less than 6.0%.