Abstract

Exposure to pesticides can represent a potential risk to humans. Agricultural workers are at risk of chronic toxicity. Hence, the evaluation of pesticide residues in their blood gives an indication about the extent of exposure and help in assessing adverse health effects. The aim of our study was to develop analytical method for the simultaneous determination of some residues of pesticides using gas chromatography-mass spectrometry (GC-MS). This method involves a liquid-liquid extraction procedure. Pesticide residues were separated and detected using GC-MS, and acquisition was performed in the sellected ion monitoring (SIM) mode. For most of the pesticides, average recoveries ranged between 65 and 101% at three different fortification levels. The linearity of the method was satisfactory in the range of 5 to 50 ng/ml, with a correlation coefficient between 0.998 and 0.999, depending on the analyte. The estimated limit of detection and limit of quantification ranged from 2 to 5 ng/ml and from 5 to 10 ng/ml, respectively. The method precision and accuracy were found to be satisfactory at three concentration levels. The variation coefficients of intra-day and inter-day precision ranged from 0.4 to 14% and from 2.5 to 15%, respectively for most studied pesticides.

Key words: Analytical methods, human serum, GC-MS, pesticide residues, validation.

Abbreviation

Abbreviations: KC, Knudson C; MS, Murashige and Skoog; VW, Vacin and Went;VJ, Vejsadova; PLBs, protocorm like bodies; NAA, α- naphthalene acetic acid; IBA,indole-3- butyric acid; IAA, indole acetic acid; P, peptone; AC, activated charcoal;MES, morphoinoethane sulphonic acid.