Liquid chromatography-electrospray ionization-tandem mass spectrometry method for determination of twenty multi-class pesticide residues in cashew

- Validation of multiresidue method was satisfactory using LC-ESI-MS/MS.
- QuEChERS method was effective for the analysis of 20 multi-class pesticides in cashew.
- Pesticides investigated were not detected in commercial samples of cashew.
- The validated method can assist government agencies to improve food safety.

This paper describes an analytical methodology employing the extraction QuEChERS (Quick, Easy, Cheap, Effective, Robust and Safe) method and liquid chromatography coupled to mass spectrometry using electrospray ionization source (LC-ESI-MS/MS). The methodology was validated for the determination of twenty multiclass pesticides in cashew. It was evaluated for selectivity, linearity, limits of detection (LOD) and quantification (LOQ), matrix effect, as well as the precision and accuracy in terms of percentage of recovery. Analyses were performed by selected reaction monitoring (SRM) using two transitions (precursor ion → ion product). All pesticides studied showed good linearity with correlation coefficient greater than 0.99. LODs and LOQs ranged from 0.10 to 0.25 ng g−1 and 0.30 to 0.75 ng g−1, respectively. Due to the complexity of the sample, study the effect matrix was performed. Cashew apples samples spiked (5, 50 and 100 ng g−1) showed recovery results ranging from 66 to 119 g/100 g, and RSD ≤ 12%, which is in accordance with standard recommended by Brazilian rules (ABNT NBR 14029/2005), except simazine. The validated method was applied to commercial samples obtained in Fortaleza-CE, Brazil, but no contamination of pesticides residues was observed.