Analytical & Testing Center of Beijing Normal University, Beijing 100875, China.
J Chromatogr A. 2011 Jun 3;1218(22):3521-8. doi: 10.1016/j.chroma.2011.03.065. Epub 2011 Apr 4.
A novel approach for identification and determination of emulsion explosives with Span-80 (sorbitol mono-oleate) as the emulsifier and their postblast residues by gas chromatography-mass spectrometry (GC-MS) has been developed. 24 kinds of emulsion explosives collected have been processed by transesterification reaction with metholic KOH solution and the emulsifier has turned into methyl esters of fatty acids. From the peak area ratios of their methyl esters, most of these emulsion explosives can be differentiated. In order to detect the postblast residues of emulsion explosives, the sorbitols in the emulsifier Span-80 obtained after transesterification reaction have been further derivatized by silylation reaction with N,O-bis-(trimethylsilyl)trifluoroacetamide (BSTFA) containing 1% trimethylchlorosilane (TMCS) as the derivatizing reagent. The derivatization conditions were optimized and the derivatives were determined by GC-MS. The results showed that the silylation derivatives of sorbitol and it isomers, combined with hydrocarbon compounds and methyl esters of fatty acids, were the characteristic components for identification of the emulsion explosives. The established approach was applied to analyze the postblast residues of emulsion explosives. It has been found that the method was sensitive and specific, especially when detecting the derivatives of sorbitol and its isomers by GC-MS in selecting ion mode. The information of the characteristic components can help probe the origin of the emulsion explosives and providing scientific evidences and clues for solving the crimes of the emulsion explosive explosion.
已开发出一种新方法，通过气相色谱-质谱联用仪（GC-MS），利用 Span-80（山梨糖醇单油酸酯）作为乳化剂，对乳化炸药及其爆炸后的残留物进行鉴定和测定。对收集到的 24 种乳化炸药进行甲酯化反应，用甲醇 KOH 溶液处理，乳化剂转化为脂肪酸甲酯。根据其甲酯的峰面积比，可以区分大多数乳化炸药。为了检测乳化炸药爆炸后的残留物，对甲酯化反应后获得的乳化剂 Span-80 中的山梨糖醇进行硅烷化反应，用含 1%三甲基氯硅烷（TMCS）的 N,O-双（三甲基硅基）三氟乙酰胺（BSTFA）作为衍生试剂进行衍生化。优化了衍生化条件，并通过 GC-MS 对衍生化产物进行了测定。结果表明，山梨糖醇及其异构体的硅烷化衍生物与碳氢化合物和脂肪酸甲酯结合，是鉴定乳化炸药的特征成分。所建立的方法已用于分析乳化炸药爆炸后的残留物。结果表明，该方法具有较高的灵敏度和特异性，特别是在 GC-MS 选择离子模式下检测山梨糖醇及其异构体的衍生物时。特征成分的信息有助于探究乳化炸药的来源，并为解决乳化炸药爆炸犯罪提供科学证据和线索。
