A novel and sensitive kinetic method for the determination of malathion using chromogenic reagent

A novel and sensitive kinetic spectrophotometric method for the determination of malathion has been developed. The method is based on the oxidation of malathion with slight excess of N-bromosuccinimide (NBS) at 30 °C where unconsumed NBS was monitored with safranine dye spectrophotometerically at λmax 530 nm using fixed time procedure after 10 min of the reaction. The oxidized product was characterized as malaoxon by Fourier transformation infrared (FTIR) spectroscopy. Beer's law was obeyed in the concentration range of 0.025-0.25 μg mL− 1. Important analytical parameters such as time, temperature, reagents concentration, and acidity have been optimized for the reaction. Sandell's sensitivity and molar absorptivity for the reaction system were found to be 0.0003 μg cm− 2 and 9.6 × 105 L mol− 1 cm− 1 respectively. The proposed method was successfully applied for the determination of malathion in different samples with satisfactory results. The results were compared with those obtained by GC-MS methods.