Distribution of pesticides in different commonly used vegetables from Hyderabad, India

In this study, we assessed the exposure of urban populations to different classes of organophosphate pesticides due to the consumption of different types of vegetables. Liquid chromatography-mass spectrometry was used for quantification, while the quick, easy, cheap, effective, rugged and safe extraction method was used to isolate eighteen organophosphate pesticides found in vegetable samples (eggplant, ladyfinger, cauliflower, cabbage, tomato and chili) at concentration of μg/kg. This method was accurate (≥ 99.5%) and possessed a limit of detection and quantification in the range of 0.002-0.099 and 0.009-0.337 μg/kg respectively. The coefficients of variation (≥ 0.9999) were less than 2% at the low end of the linear range of the method. The mean recovery ranged between 94 and 103%, and the % relative standard deviation (RSD) was generally below 10%. These results demonstrate that the methodology is both highly efficient and robust. The proposed method was successfully applied to the analysis of vegetable samples collected from different government farmer markets and street shops in urban areas. The mean concentration of chlorpyrifos in eggplant (24.02 μg/kg), cabbage (10.55 μg/kg), cauliflower (2.85 μg/kg), tomato (178.87 μg/kg) and ladyfinger (2.49 μg/kg) differed significantly (p < 0.002). Similarly, the mean concentration of triazophos in eggplant (0.863 μg/kg), cabbage (2.21 μg/kg), cauliflower (0.491 μg/kg), tomato (3.01 μg/kg) and ladyfinger (2.49 μg/kg) differed significantly (p < 0.007). A similar trend was observed for acephate, fenitrothion and phosalone. This study may be helpful in developing a regional exposure database and in facilitating assessment of health risks from pesticide exposure in our day-to-day lives.

► The LC-MS/MS combined with QuEChERS method was used for analysis of eighteen organophosphate pesticides in vegetable samples. ► This method was accurate (≥ 99.5%), as it possessed limits of detection in the 0.002-0.0999 μg/kg ranges, respectively. ► Mean recoveries ranged between 94 and 103%, and relative standard deviations (% RSD) were generally below 10%. ► The chlorpyrifos mean concentrations of eggplants differed significantly (p < 0.002) among the vegetables. ► Triazophos mean concentration of eggplants differed significantly (p < 0.007) among the vegetables.