气相色谱-原子发射光谱和溴加成法联合测定含烯烃汽油中的烯烃单体 Ⅰ.汽油中烯烃保留值的研究

Detailed Alkene Determination by Bromination and Gas Chromatography with Atomic Emission DetectionⅠ. Identification of the Bromoalkenes/Bromoalkanes in Brominated Gasoline

通过对含烯烃汽油进行溴加成反应,对汽油中烯烃的保留值进行了研究。对171个溴化产物溴代烃进行了定性,并给出了溴代烃所对应的171个烯烃的定性结果,其中对C7前的溴代烃及烯烃组分给出了结构式。定性手段主要依据汽油中混合纯烯烃样品溴化后的气相色谱 质谱联用(GC MS)数据和气相色谱 原子发射光谱(GC AED)的元素比数据,确定溴代烃及其对应烯烃单体的分子式,然后利用已有的烯烃单体文献保留值数据、纯烯烃化合物的反应结果并结合碳数规律和沸点规律,确定了烯烃单体化合物的结构。该方法最大的优点是实现了选择性检测烯烃,从而排除了其他烃类化合物对烯烃测试的干扰,因此对于汽油中烯烃的分布有着更直观的反映。

The identification of the monobromoalkenes and bromoalkanes in the product obtained by the bromination of gasoline was investigated, which is one of the problems to be solved when applying the method to analyze the gasoline olefin by the bromination and gas chromatography coupled with atomic emission detector. The olefin fraction separated from gasoline and its brominated product were selected as the objective samples for identifcation. Gas chromatographymass spectrography (GCMS), GCatomic emission detection (AED), pure bromoalkanes, published retention indices and theoretical or empirical rules about component retention behavior in GC, such as boiling point rule and carbon number rule etc, were used to give the identified results. The information about the molecular formulas of the bromoalkanes in the product of the brominated gasoline was provided according to the bromine isotopic ion peaks given by GCMS and the empirical/molecular formula calculated from the responses of bromoalkane in the carbon /bromine selective chromatograms detected by GCAED. The more exact identification, eg the structural formula of bromoalkane peaks, was deduced by the following ways: (1) GCAED chromatograms of the pure bromoalkanes produced by brominating known alkenes; (2) the published retention indices about detailed alkene hydrocarbons in gasoline; (3) the carbon number rule and boiling point rule of bromoalkane homologous series. On the basis of the above research, 171 gas chromatographic retention indices for C4 to C11 monobromoalkene and bromoalkane in brominated gasoline on HPPONA column are presented. Meanwhile, the data of the alkenes, which were present originally in the gasoline are also given, and for bromoalkanes and their corresponding alkenes before C7, the identification was almost realized one by one. 