Rapid separation of post ‐blast explosive residues on glass electrophoresis microchips

This study describes the development of an analytical methodology based on the use of microchip electrophoresis (ME) devices integrated with capacitively coupled contactless conductivity detection (C4D) for the separation and detection of inorganic anions in post ‐blast explosive residues. The best separation condition was achieved using a running buffer composed of 35 mmol/L lactic acid, 10 mmol/L histidine and 0.070 mmol/L cetyl(trimethyl ammonium) bromide. For C4D measurements, the highest sensitivity was obtained applying a 700  kHz sinusoidal wave with excitation voltage of 20 Vpp. The separation of Cl−, NO3−, NO2−, SO42 −, ClO4− and ClO3− was performed withinca. 150 s with baseline resolution and efficiencies between 4.4 × 104 and 1.7 × 105 plates/m. The found limits of detection ranged between 2.5 and 9.5  μmol/L. Lastly, real samples of post‐blast explosive residues were analyzed on the ME‐C4D devices obtaining successfully the determination of Cl−, NO3− and SO42 −. The achieved concentration values varied between 12.8 ࣧ72.5 mg/L for Cl−, 1.7 ࣧ293.1 mg/L for NO3− and 1.3 ࣧ201.3 mg/L for SO42 −. The data obtained using ME ‐C4D devices were in good agreement with the concentrations found by ion chromatography. The approach reported herein has provided short analysis time, instrumental simplicity, good analytical performance and low cost. Furthermore, the ME ‐C4D devices emerge as a powerful and portable analytical platf...

Source: Electrophoresis - November 8, 2018 Category: Biochemistry Authors: Kemilly M. P. Pinheiro, Roger C. Moreira, Kariolanda C. A. Rezende, M árcio Talhavini, Lucio P.L. Logrado, José A. F. Baio, Marcos R.V. Lanza, Wendell K. T. Coltro Tags: Research Article Source Type: research