Cloud point extraction for determination of Diazinon: Optimization of the effective parameters using Taguchi method

Abstract Since Diazinon is one of the organophosphorous compounds which are harmful for human organisms, a simple, sensitive and accurate testing method for extraction and determination of this pesticide is mandatory. In this project, Cloud Point Extraction (CPE) method was developed for determination of Diazinon in aqueous samples. CTAB (cetyl trimethyl ammonium bromide) was used as cationic surfactant to extract and preconcentrate of Diazinon at the same time and the extracted Diazinon was determined by UV spectrophotometery. Taguchi L 9 array was employed for design of experiments to investigate influences of surfactant concentration, salt concentration, temperature and incubation time as effective parameters. According to the analysis of variance (ANOVA) results, the most effective parameter of the process is incubation time. The results show that a surfactant concentration of 10 − 5 % (w/v), an incubation time of 30 min, a KI concentration of 10 − 6  mol L − 1 and a temperature of 35 °C are the best operating conditions. Also, the linear calibration graph in the range of 0.02–24 ng ml − 1 of Diazinon with r = 0.999 was obtained. The limit of detection (LOD) was 0.02 ng ml − 1 and relative standard deviation (RSD) for 15 ng ml − 1 of Diazinon was 0.76%.