质谱法测定柴油烃类组成的不确定度评定

Uncertainty Evaluation in the Determination of Hydrocarbon Composition in Diesel by Mass Spectrometry

采用石化行业标准SH/T0606-2005《中间馏分烃类组成测定法(质谱法)》,以C30正构烷烃作为内标,用气质联用仪测定柴油中的十一种烃类组成,包括链烷烃、一环环烷、二环环烷、三环环烷、烷基苯、茚满或萘满、茚类和/或CnH2n-10、萘类、苊类和/或CnH2n-14、苊烯类和/或CnH2n-16、三环芳烃和/或CnH2n-18。结果表明,该方法的内标加入对不确定度影响较小,样品量取对不确定度影响较大。重复测定引入的不确定度对不同的烃类影响不同,影响程度大小排序为:茚满>萘>茚类>烷基苯>苊类>二环烷烃>萘类>三环烷烃>链烷烃>苊烯类=三环芳烃。

Based on the petrochemical industry standard SH/T 0606-2005 Intermediate Distillate Hydrocarbon Composition Determination by Mass Spectrometry, using C30 n-alkanes as internal standard, eleven hydrocarbon components in diesel were determined by GC-MS, including alkanes, monocyclohexanes, dicyclohexanes, tricyclohexanes, alkylbenzene, indene or naphthalene, indene and/or CnH2n-10, naphthalene, acenaphthene and/or CnH2n-14, acenaphthene and/or CnH2n-16 and tricyclic aromatic hydrocarbons and/or CnH2n-18.The sources of uncertainty were analyzed and the expanded uncertainty was given by calculating each uncertainty component. The results showed that the internal standard had little effect on the uncertainty, while the sample measurement had bigger effect. The uncertainty introduced by repeated experiment had different effect on different hydrocarbons. The order of influence degree was as follows: indene > naphthalene > indene >alkylbenzene> amaranth >dicyclic alkanes > naphthalene > tricyclic alkanes > chain alkanes >acenaphthene = tricyclic aromatic hydrocarbons.