Development of An Analytical Method for Pesticide Residues in Fruit or Vegetable Juices

Abstract

       The method for analysis of 49 pesticides including Organochlorine compounds (OCs), Organophosphorus compounds (OPs) and Synthetic Pyrethroids (SPs) in fruit or vegetable juices was developed. The AOAC Official Method 2007.01 and the method of Anastassiades M. et al have been modified by using salting out technique in extraction step to improve the efficiency of extraction. Pesticide residues were detected and quantified by GC-μECD and GC-FPD. Guava juice was used as representative matrix for method validation. Performance characteristics of a developed method defined by Limit of detection was 0.01 mg/kg and Limit of quantitation was 0.03 mg/kg. The method showed linearity of working range for all pesticides between 0.03-0.2 mg/kg. The accuracy expressed as percentage of recovery and the precision expressed as HORRAT were 64.2-118.6% and 0.1-1.3, respectively. The validation data showed that the developed method was fit for purpose and can be used in routine work. To monitor pesticide residues in beverages made from fruits and vegetables sold in Bangkok and vicinity area, 100 samples of orange juice, guava juice, pomegranate juice, carrot juice and other vegetable juices were collected and analyzed. Among those pesticides analyzed, the OPs was most frequently detected which were chlorpyrifos, ethion, pirimiphos-methyl and profenofos were found in the range of less than 0.03-1.22 mg/kg. Only cypermethrin in SPs was found with the residual level of 0.04 mg/kg. OCs residue was, however, not detected.