Micro-extraction, pre-concentration, and microfluidic-based separation of organophosphate insecticides followed by the miniaturized electrochemical detection system

Introduction: A new analytical method based on the coupling of microextraction and microfluidics was developed investigated for pre-concentration, separation, electrochemical detection fenitrothion (FT) parathion (PA) at sub-ppm concentrations. Method: In first step, microchip capillary electrophoresis technique used to serve as a separation system. Analytes were injected into 40 mm long microchannel with 10 sidearms. Then, they separated by applying direct electrical field (+1800V) between buffer reservoirs. 2-(n-morpholino)ethanesulfonic acid (MES) (20 mM, pH 5) running buffer. The performed using three Pt microelectrodes width working, counter, reference electrodes (50, 250, 250 µm, respectively) in out channel approach. Results: system devised have optimum potential equal -1.2 V vs. Pseudo Ref. electrode. dimensions SU-8 20 µm depth 50 width. second an air-assisted liquid-liquid extraction preconcentration analytes from human blood plasma. 1, 2 di-bromoethan extractant solvent, preconcentrated, sedimented solvent (50 µL) evaporated 60 ˚C water bath followed substitution containing 10% ethanol. cycles found 8 adding 1% NaCl aqueous phase. Analyzing time mentioned less than 100s, precision range 3.3 – 8.2 linear 0.8 100 ppm 1.2 - FT PA, respectively. recoveries about 91% 87% limits PA 240 360 ppb, Finally, reliability GC-FID. Conclusion: proposed device validated can be situ portable detecting insecticides.