深度加氢柴油中咔唑类化合物的测定

建立了采用气相色谱-四极杆-飞行时间质谱仪定性、定量分析深度加氢柴油中咔唑类化合物的方法。该方法可对质量分数为ng/g级的5类咔唑类化合物进行分析，定量标准曲线的线性相关系数R²大于0.9980，回收率范围为81.86%～89.27%，相对标准偏差范围为2.36%～4.14%，重复性较好，最低检出限为0.000 4～0.001 6mg/L，定量限为0.001 2～0.005 4 mg/L，灵敏度较高。利用该方法对不同加氢深度的加氢柴油中咔唑类化合物进行分析检测，结果表明：咔唑、甲基咔唑易于在加氢精制过程中脱除；1位、8位甲基取代的二甲基咔唑类、三甲基咔唑类化合物空间位阻较大，在加氢条件下较难脱除。

COMPARATIVE STUDY ON CLOSED CUP FLASH POINT TEST METHODS

A gas chromatography quadrupole time-of-flight mass spectrometry method was developed for the qualitative and quantitative measurement of carbazole compounds in deeply hydrogenated diesel. This method could be used for qualitative analysis of five carbazole compounds with mass fraction in ng/g level，the linear correlation coefficient of the quantitative standard curve was above 0.998 0, and the recovery range was 81.86%-89.27%. The relative standard deviation range was 2.36%-4.14%，showing that the quantitative accuracy of the method was good. The minimum detection limits were 0.000 4-0.001 6 mg/L and the quantitation limits were 0.001 2-0.005 4 mg/L，illustrating that the sensitivity of the method was high. The carbazole compounds in hydrogenated diesel with different hydrofining depths were analyzed by this method. The results showed that carbazole and methyl carbazole was easily removed in the hydrofining process, and the 1- or 8-methyl-substituted dimethylcarbazole and trimethylcarbazole compounds had large steric hindrance and were difficult to be removed by hydrogenation.