Seyed Jamaleddin Shahtaheri
Tehran University of Medical Sciences, Iran
Title: Development of dispersive liquid-liquid microextraction procedure for trace determination of pesticide malathion in urine samples
Biography
Biography: Seyed Jamaleddin Shahtaheri
Abstract
Background: Measurement of pesticides in biological matrices is a serious challenge for researches because of their very low concentration in different matrices. The aim of this study was to develop a new sample preparation method with high accuracy, validity, simplicity as well as a short retention time for chromatographic determination of the pesticide malathion.
Methods: Dispersive liquid-liquid micro-extraction (DLLME) technique coupled with high performance liquid chromatography equipped with ultra violet detector (HPLC-UV) was developed for trace extraction and determination of pesticide malathion in human urine samples. One variable at a time (OVAT) method was used to optimize parameters affecting the malathion extraction. Different parameters such as extraction solvent, disperser solvent, volume of the extraction solvent, volume of the disperser solvent, centrifugation time and speed salt addition, and sample pH were studied and optimized.
Results: Under the optimized conditions, the limit of detection and enrichment factor of the developed procedure were 0.5 μgL-1 and 200, respectively. The calibration curve was linear in the concentration range of 2-250 μgL-1. The relative standard deviation for six replicate experiments at 200 μgL-1 concentration was less than 3%. The relative recoveries of spiked urine
samples were 96.3%, 101.7% and 97.3% at three different concentration levels of 50, 200, and 1000 μgL-1, respectively.
Conclusion: According to the obtained results, DLLME procedure was successfully developed for the extraction of malathion from human urine samples. Compared to other extraction techniques, the proposed procedure had some advantages such as shorter extraction time, better reproducibility, and higher enrichment factor.