同时裂解甲基化气相色谱法鉴别合成胶粘剂

Identification of Synthetic Adhesives by Simultaneous Pyrolysis Methylation Gas Chromatography

应用同时裂解甲基化气相色谱法 (Py Me GC)对合成胶粘剂进行了鉴别。采用热丝型裂解器、氢火焰离子化气相色谱仪、FFAP毛细管柱、程序升温方式及季铵盐甲基化试剂 ,对刑事案件中常见的丙烯酸酯类及其改性体、醋酸乙烯酯、聚乙烯醇等合成胶粘剂进行了测定 ,并对样品裂解各主要组分峰进行了GC/MS定性分析 ,同时比较了相同样本用常规裂解气相色谱法 (Py GC)测定的结果。结果表明 :Py Me GC法比Py GC法可获得更多的物质组分信息 ,是一种适用于法庭科学鉴定的方法。

At present, pyrolysis gas chromatography (Py GC) is an effective analytical method for trace synthetic adhesives. Synthetic adhesives are usually composed of polar components. Thus, the polar pyrolysis products are normally difficult to measure by Py GC due to their partial or complete adsorption in the pyrolysis zone, injection system or capillary column and the accuracy of results is seriously affected. Simultaneous pyrolysis methylation gas chromatogaphy (Py Me GC) is a fast analytical method which was developed in recent years for polar compounds. The five synthetic adhesives have been identified by using Py Me GC in our study. Analytical conditions were: filament pyrolysis apparatus, flame ionization detector (FID), gas chromatograph, FFAP capillary column (30 m×0.25 mm i.d.) and a quaternary ammonium salt as methylating agent. Major peaks of the products of pyrolysis were analysed qualitatively by GC/MS and comparisons were also made between the results by Py Me GC and those by Py GC. The information gained from the components of substances by Py Me GC is more than that by Py GC. The method is suitable for identifying synthetic adhesives of trace evidence in forensic science.