Analytical Techniques for Determining Chloropyrifos in Fruits and Vegetables

Abstract

Highly sensitive spectrophotometric and gas chromatographic methods were developed for the determination of chloropyrifos. Alkaline hydrolysis of chloropyrifos to 1,2,4-trichloropyridine was the basis followed by coupling with congored in presence of nitric acid. The absorption maxima of blue color formed at 800-900C was formed at 605nm.Beer’s law was obeyed in the range of 0.5-5.7 ppm. The standard deviation was found to be ± 0.005.The method was free from other pesticide interferences. The method was applied to various fruits and vegetables procured at various agricultural fields at sabbavaram area, Visakhapatnam, India and found satisfactory. Keeping in view of extensive use of pesticides on fruits and vegetables damaging the ecological balance. Determination of pesticide residue in The various vegetables collected are cauliflower, potato, spinach, and fruits suchas pinkapple, grapes etc were analysed by using Gas –chromatography with electron capture detector (GC-ECD). GC-ECD has great potential for determining organochlorine pesticides in food extracts at low levels.  Residues were extracted with hexane, dichloromethane and ethyl acetate (1:1% V/V).Clean up procedure was carried by applying solid phase extraction column. The recoveries of chloropyrifos pesticide in fruits and vegetables selected were in the range of 80 to 98% fortified at 0.5 mg/Kg. Some grape samples showed above the limit of quantification.