Simultaneous determination of inorganic ions in post-blast residues using capillary electrophoresis

Abstract

Capillary electrophoresis method for simultaneous determination of inorganic anions and cations was developed using 2,6-pyridinedicarboxylic acid (PDC) as a background electrolyte (BGE) with indirect UV detection. In order to detect both anions and cations simultaneously, the electromagnetic flow was reversed by the addition of cetryltrimethylammonium hydroxide (CTAH). The parameters which influenced the separation of inorganic ions such as electrolyte pH, concentration of PDC, applied voltage and temperature were investigated. Four anions (Cl-, NO3-, SO42-, SCN-) and three cations (Ca2+, Fe2+, Fe3+) were successfully determined simultaneously in less than 7 min under the optimized conditions (25mM PDC, 0.5mM CTAH, pH 4.7). The method was applied to the analysis of post-blast explosive residues of black powder and ammonium nitrate-fuel oil (ANFO). The analytical performances of the method are discussed in terms of analysis time, repeatability, reproducibility, linearity of response and detection limits.