Rapid and Simple Method for Determination of Thiram in Fruits and Vegetables with High-Performance Liquid Chromatography with Ultraviolet Detection

Abstract

A rapid and sensitive HPLC-UV method was developed for determination of the dithiocarbamate thiram in fruit and vegetables. The method was based on extraction with a mixture of ethyl acetate and cyclohexane in an ultrasonic bath for 15 min. The analysis was done on an Apex II diol column in a straight (normal) phase HPLC system with UV detection. The average recoveries for spiked samples, 0.1−1.3 mg/kg, of apple, cucumber, lettuce, nectarine, plum, pear, and grapes were in the range of 73−86% with a relative standard deviation of 3.1−18%. Lower recoveries, 40−66%, were obtained for tomatoes, green pepper, raspberries, and strawberries, which might be explained by an enzymatic degradation of thiram. Limit of quantification was found to be 0.1−0.2 mg/kg for all tested matrices. Keywords: Thiram; HPLC-UV; fruits; vegetables; degradation