METHOD VALIDATION AND CALCULATION OF MEASUREMENT UNCERTAINTY FOR PESTICIDE RESIDUE ANALYSIS IN FRESH RED PEPPER

Abstract

A multiple analysis method based on QuEChERS (fast, easy, inexpensive, effective, robust and safe) extraction method and liquid chromatography-tandem mass spectrometry (LC – MS/MS) was developed for 39 selected pesticides in fresh red pepper. This method has been validated according to the Sante guide published by the European Union Reference Laboratories (EURLs). The linearity study was conducted in the range of 1-80 µg/kg and in seven different concentrations. The correlation coefficients of the calibration curves were (R2)> 0.992. Quantification limits (LOQs) ranged from 4 to 19 μg kg-1. The recovery values were between 70.84% and 108.0%. The repeatability values (RSDr), which were between 0.99% and 17.5%in terms of in-laboratory reproducibility values (RSDWR), were determined to be between 0.98% and 19.57%. Repeatability and trueness parameters were used to calculate measurement uncertainty. The extended uncertainty values were calculated as 20.88% to 49.94%. The method was successfully used to analyze 22 fresh red pepper samples. Nine different pesticide residues were identified in 12 samples. The amount of carbendazim in a sample was found to be above the legal limits of the EU and Turkey. A residue of carbofuran, which is banned in Turkey, was found in one sample.