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    全二维气相色谱法快速测定车用汽油中的12种添加剂

    Quick Determination of Twelve Additives in Motor Gasoline by Comprehensive Two-Dimensional Gas Chromatography

    • 摘要: 建立了一种采用全二维气相色谱法测定车用汽油中的12种添加剂(包括3种酯类、6种苯胺类、3种有机金属类添加剂)的方法。汽油样品直接进样后,将经一维HP-INNOWAX色谱柱分离出的分析物以脉冲的方式流出到二维DB-17ms色谱柱中进行再次分离,得到的目标分析物用氢火焰离子化检测器(FID)测定。采用内标法定量,采用基质匹配法配制混合标准溶液系列。结果显示:标准曲线的线性范围为50~2 000 mg·L-1,相关系数均在0.999 0以上,检出限(3S/N)为12.87~24.82 mg·L-1。对空白汽油样品进行3个浓度水平的加标回收试验,得到的回收率为94.4%~118%,测定值的相对标准偏差(n=6)为0.44%~4.0%。将用GB/T 32693-2016、GB/T 33646-2017及电感耦合等离子体原子发射光谱法(ICP-AES)分别测得的2个实际样品中酯类添加剂、苯胺类添加剂、金属元素的结果同该方法的进行比对,95%的置信水平得到的F检验和t检验结果显示:该方法和其他3种方法测定结果的精密度无显著性差异;该方法和GB/T 33646-2017及ICP-AES测定结果无显著性差异,由于GB/T 32693-2016测定值偏低,和该方法存在显著性差异。

       

      Abstract: A method based on the comprehensive two-dimensional gas chromatography (GC×GC) was established for determination of the twelve additives including three ester additives, six aniline additives and three metal-organic additives in motor gasoline. The gasoline sample was injected directly, separated by 1st dimensional HP-INNOWAX chromatographic column, and then pulsed out to 2nd dimensional DB-17ms chromatographic column for further separation. The target analytes were detected by FID. Internal standard method was applied for quantification, and matrix matching method was used to prepare mixed standard solution series. As results showed that the linearity range of standard curves of twelve additives was found same in the range of 50-2 000 mg·L-1, with correlation coefficients all above 0.999 0 and detection limits (3S/N) in the range of 12.87-24.82 mg·L-1. The spiked recovery tests were made on blank gasoline samples at three concentration levels, giving recoveries in the range of 94.4%-118%, with RSDs (n=6) of determined values in the range of 0.44%-4.0%. Analytical results of ester additives, aniline additives, metal elements in two actual samples obtained by the proposed method were compared to those of GB/T 32693-2016, GB/T 33646-2017 and ICP-AES, and results of F-test and t-test at 95% confidence level showed that there was no significant difference in precision between this method and other three methods; the results using this method were no significantly different with GB/T 33646-2017 and ICP-AES, but significantly different between GB/T 32693-2016 and this method due to the lower measurement of GB/T 32693-2016.

       

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