Determination of Diazinon, Phosalone and Endosulfan in Raw Milk using Continuous Sample Drop Flow Microextraction Followed by High Performance Liquid Chromatography‒Ultraviolet Detection

Abstract

The purpose of this study was to determine common pesticides in raw milk from the industrial cattle houses of Kermanshah region of Iran. A novel, simple, inexpensive, reliable and environmentally friendly method based on continuous sample drop flow microextraction combined with high-performance liquid chromatography-ultraviolet detection was developed. In this technique, a few microliters of organic solvent is transferred to the bottom of a conical test tube and the aqueous solution in form of fine droplets passes through the organic solvent. At this stage, target analytes are extracted into the organic solvent. After extraction, 20 μL of organic solvent was injected into the analytical instrument. Some effective parameters on extraction were studied and optimized. Under the optimum conditions, the calibration graphs are linear in the range of 1–800 µg/L and limits of detection are in the range of 0.3–1.0 µg/L. Repeatability (intra-day) and reproducibility (inter-day) of the method based on five replicate measurements of 100 µg/L of target pesticides were in the range of 2.7–4.1 and 4.3–7.2%, respectively. The enrichment factors and recoveries are in the range of 308–372 and 77–93%, respectively.