Simultaneous determination of 78 pesticide residues and 16 mycotoxins in tsampa by an improved QuEChERS method coupled with ultra performance liquid chromatography-tandem mass spectrometry†

Abstract

Tsampa may contain pesticide residues and mycotoxins, which may pose a risk to human health. Currently, pesticide detection and mycotoxin detection are two independent experiments. To improve the efficiency of the analysis, a method based on QuEChERS combined with ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) for the simultaneous determination of 78 pesticides and 16 mycotoxins in tsampa was developed. All the target compounds showed good linear correlation with correlation coefficients (R²) greater than 0.9990. The limits of detection (LODs) and limits of quantification (LOQs) were in the ranges of 0.10–3.00 μg kg⁻¹ and 0.40–10.00 μg kg⁻¹, respectively. The average recoveries of the pesticides and mycotoxins spiked at the 1, 2, and 10-fold LOQ were in the range of 73.0–115.2%, and the relative standard deviations (RSDs) were lower than 11.7%. This method was applied to 19 batches of real samples in which 32% of samples exceeded the maximum residue limits of the European Union involving aflatoxin G2, ochratoxin A, and hexaconazole. It proved to be excellent, efficient, greatly simplified, and highly applicable, which could reduce the workload and time significantly for the daily monitoring of the pesticides and mycotoxins in tsampa.