Evaluation of the Applicability of Modified QuEChERS with Small-Scale SPE for the Analysis of Neonicotinoid Insecticides in Beetroot and Paprika Powder

Background As the demand for natural colorants is expected to increase in the future, it is important to analyze pesticide residues to investigate the relationship between exposure and health risks. A modified QuEChERS (quick, easy, cheap, effective, rugged, and safe) analytical method, which uses small-scale SPE for the cleanup process, is increasingly used in Japan. Since this method has hardly been studied for the analysis of pesticides in natural food colorants, it is necessary to evaluate its performance. Objective This study aimed to evaluate the applicability of the modified QuEChERS method for the analysis of neonicotinoid insecticides (NEOs) in beetroot and paprika selected from natural colorants. Methods The modified QuEChERS method was evaluated by a recovery study using blank beetroot and paprika powder. The matrix effect (ME) was also evaluated in detail for the analysis by the modified QuEChERS and liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS). These results were compared with those obtained by Japanese official multiresidue method. Results The mean recovery, intraday repeatability, and interday reproducibility for the modified QuEChERS were acceptable according to the validation guideline. The MEs for the modified QuEChERS were not particularly strong for the NEOs in the beetroot and paprika even when the isotopically labeled internal standards were not used. Conclusions The evaluation of the modified QuEChERS was successfully tested and demonstrated the suitability of this method for the analysis of NEOs in beetroot and paprika. Highlight The modified QuEChERS is not only accurate but is also a fast and environmentally friendly method for analyzing NEOs in beetroot and paprika.