Poly(vinylidene fluoride) membrane based thin film microextraction for enrichment of benzoylurea insecticides from water samples followed by their determination with HPLC

Thin-film microextraction (TFME), a new geometry for solid-phase microextraction, has become an attractive sample-preparation technique. Compared to other microextraction approaches, the sensitivity of this technique was enhanced without sacrificing the sampling time due to the high surface area-to-volume ratio together with the increase of extraction-phase volume. In this paper, a new TFME method based on poly(vinylidene fluoride) membrane was developed for the extraction of benzoylurea insecticides (diflubenzuron, triflumuron, hexaflumuron and teflubenzuron) from water samples followed by their determination with high performance liquid chromatography-diode array detection. Under the optimal conditions, good linearity was observed over the concentration range of 0.5-100.0 ng/mL with correlation coefficient greater than 0.9994. The limits of detection (S/N = 3) of the method for the target analytes were 0.1 ng/mL. Mean recoveries ranged from 87.7% to 103.9% with relative standard deviations lower than 6.5%. The results indicated that the developed TFME method is simple, efficient, and cost effective. (C) 2014 Qiu-Hua Wu and Zhi Wang. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.