Electrochemical detection of the explosive, hexamethylene triperoxide diamine (HMTD)

Abstract

A rapid electrochemical detection scheme for the improvised explosive, hexamethylene triperoxide diamine (HMTD) is demonstrated. This is based on the hydrolysis of HMTD releasing H 2O 2 and the electrochemical redox cycling of Fe II/IIIEDTA via the following scheme: Fe IIIEDTA + e −→Fe IIEDTA Fe IIEDTA + HOOH→Fe IIIEDTA + HO + HO − where FeEDTA is the ethylenediaminetetraacetate complex. Cyclic voltammetric results indicate an electrocatalytic (EC′) mechanism. Mass transport aided chronoamperometry at a carbon disk electrode ( E step = − 400 mV vs. Ag/AgCl) gave a limit of detection of 30 μM (3 S b/ m). Most interestingly, the hydrolysis of HMTD was found to be rapid under mild reaction conditions which was found to be complete, and nearly instantaneously when exposed to a 50/50 (v/v%) water/acetonitrile solution at pH 2.1. This is in contrast with previous investigations that require harsher conditions. Neutralization or further derivatization steps were not necessary as the Fe II/IIIEDTA complex acted as an electron shuttle under these conditions. These results indicate a basis for a fast, one-step, and inexpensive detector for HMTD. Based on the results of a previous study, the simultaneous detection of HMTD with another improvised explosive, triacetone triperoxide is a strong possibility.