Evaluation of pesticide residues in rice marketed in Cape Verde by QuEChERS-LC/GC-MS analysis

Abstract

In this work, a multiresidue pesticide analysis using both gas chromatography and ultra-high performance liquid chromatography coupled to mass spectrometry systems has been conducted to determine 151 pesticides in rice samples consumed by the population of Cape Verde. The extraction and clean-up procedures were carried out by the QuEChERS method. The validation of both methodologies achieved determination coefficients higher than 0.9902 in matrix-matched calibration, relative recovery values in the range 58–120% with relative standard deviation lower than 20%, and limits of quantification of the method in the range 0.008–0.017 mg/kg, which agreed with the legal limits established by both EU regulations and the Codex Alimentarius guidelines. Among the total of 98 rice samples analysed, 91 samples were contaminated by pesticides at concentrations up to 18.3 mg/kg, with pirimiphos-methyl, propiconazole, tebuconazole, and imidacloprid being the most frequently detected. Following EU regulations, 14 non-compliances were found in 13 samples, whereas only one non-compliance was identified according to the Codex. Besides, a risk assessment based on the dietary exposure was performed for the pesticides found in the analysed rice samples. The results showed the need to carry out stricter controls to ensure the security of food agricultural products to protect consumers’ health.