Abstrait

Analysis of pesticide residue concentration in exported quality ceylon black tea by GC-MS.

Amaraweera OHH, Wickramasinghe I

Contamination of food commodities with pesticide residues have become a major concern throughout the world as it causes adverse health effects to the humans. Different regulatory bodies have been established MRLs for pesticide residues, in order to control the health risks. This study distinguishes the selected Ten pesticide’s residual contamination of the exported quality Ceylon black tea. The analysis was carried out by the modified QuEChERS extraction method using GCMS. And the results were compared with the Codex, EU and Japanese MRLs. Tea samples were collected from the major tea exporters in the country based on five tea grades namely OP, BOP, FBOP, BOPF and PEKOE. Method validation was performed by spiking the blank tea samples with two concentrations levels 200 ppb, 500 ppb respectively. [Recovery percentage=[Detected concentration/Spiked concentration] × 100%]. Calculated recovery percentage was 80% -120%. For accurate quantification, representative matrix-spiked calibration curves were applied to compensate matrix effects. The limit of detection for all the targeted pesticides in this study was 0.005 ppm. The results pointed out that exported quality Ceylon black tea are safe from the established limits of Codex, EU and Japanese MRL’s for the selected pesticides. The obtained data concludes that among the analyzed 15 samples, some were found with detectable amounts of pesticide residues. But none of the sample exceeded the Maximum Residue Levels established by Codex, EU and Japan. Endosulfan and bifenthrin was the main focus on the study and only one tea grade had residues more than 0.005 ppm. Other than that Chlorpyrifos, Methyl parathion, O,P-DDT were detected and at a much lower frequency. None of the analyzed teas contained residues that may be considered as being detrimental to health.