HPLC Method Development for the Fast Separation of a Complex Explosive Mixture

Abstract

The growing threat of terrorism in many parts of the world has called for the urgent need to find rapid and reliable means of analyzing explosives. This is in view to help forensic scientists to identify different swabs from post-blast debris. The present study aims to achieve an efficient separation and identification of a mixture of sixteen explosive compounds (including nitroaromatics, nitramines, and nitrate esters) by high performance liquid chromatography using a diode array detection (HPLC/DAD) and an Agilent Poroshell 120 EC-120 C18 column at two wavelengths (235 and 214 nm). Relevant chromatographic parameters such as capacity factors, resolution, selectivity and number of theoretical plates have been optimized in order to achieve the best separation of the different components. In this respect, the effects of various parameters such as gradient time, column temperature, flow rate of mobile phase and initial percentage organic mobile phase on the separation of these compounds were investigated. It was revealed that the method allowed a fairly acceptable separation of all the compounds in less than 15 minutes except for two isomers, namely 4-A-2,6-DNT, 2-A-4,6-DNT and 2,6- DNT which could not be resolved by the used C18 column. This shortcoming notwithstanding, the developed method produced satisfactory results and demonstrated sensitive and robust separation, furthermore indicating that the HPLC developed method can be both fast and efficient for the analysis of complex mixtures of explosive compounds.