Sensitive voltammetric sensing of the 2,3-dimethyl-2,3-dinitrobutane (Dmnb) explosive taggant

The highly sensitive voltammetric detection of the 2,3-dimethyl-2,3-dinitrobutane (DMNB), a required additive to commercial plastic explosives, is described. The protocol relies on a fast square-wave voltammetric measurement of the DMNB explosive taggant at an unmodified carbon fiber electrode using a phosphate buffer (pH 7.0) solution. Different solutions and, working electrodes were evaluated. Under the optimal conditions, a linear response is observed over the 300 - 3000 mu g/L DMNB concentration range examined, with a detection limit of 60 mu g/L. A highly stable response, with a relative standard deviation (RSD) of 2.6%, is observed for 30 repetitive measurements. Such electrochemical approach offers great promise for a simple, rapid, sensitive and inexpensive field screening of plastic explosives. Preliminary data illustrate the utility of electrochemical detection for electrophoretic microchips for the simultaneous measurements of DMNB, cyclotrimethylenetrinitramine (RDX) and pentaerythritoltetranitrate (PETN).