Cloud-point extraction followed by high pressure liquid chromatography with UV spectrophotometric detection for determination of permethrin in urine samples

A new, effective cloud-point extraction (CPE) method for determination of the pesticide, permethrin, from the pyrethroid group, in human urine, by high-pressure liquid chromatography with UV spectrophotometric detection, was developed and validated. The key extraction conditions were as follows: surfactant 5% (w/v) Triton X-114, temperature and incubation time of 40 degrees C and 30 min, respectively, and 100 mu L organic solvent (acetonitrile) for dissolving the micellar phase. The acetonitrile micellar phase with the isolated permethrin was analyzed by reverse-phase high-pressure liquid chromatography using the gradient flow of a mobile phase consisting of water and acetonitrile. The main analytical parameters of the developed method were mean extraction recovery (89.9%), intra-(7.1, 9.1 and 13.6% RSD for 0.25, 0.5 and 1.0 mg mL(-1) concentrations of permethrin, respectively) and interday (6.1, 10.3 and 14.1% RSD for 0.25, 0.5 and 1.0 mg mL(-1) concentrations of permethrin, respectively) repeatability, limit of detection (0.025 mg mL(-1)) and limit of quantification (0.075 mg mL(-1)), as well as the linear range (0.075-2.000 mg mL(-1), r(2) = 0.9975). The evaluated parameters have enabled the proposed method to be hopefully useful for the monitoring of permethrin in urine samples taken from individuals exposed to this pesticide.