Multiresidue GC-MS/MS pesticide analysis for evaluation of tea and herbal infusion safety

A fast, simple, low-cost and high-throughput multiresidue pesticide analysis method was developed and validated for 300 pesticides in herbal and fruit infusion samples based on modified QuEChERS (quick, easy, cheap, effective, rugged and safe) procedure combined with gas chromatography coupled with tandem mass spectrometry method (GC-MS/MS). The objectives were to develop low cost GC-MS/MS method, validate the method in accordance to SANTE/11,813/2017 guidance document and application in routine. The results obtained using different GC and MS/MS parameters were evaluated in order to develop quick, robust, accurate and effective multiresidue method. Total analysis time was 28 min with 0.6 µL injection volume. For accurate quantification, matrix-matched calibration (MMC) curves (in range of 10 µg/kg – 250 µg/kg) were applied to compensate matrix effect. The limits of quantification (LOQ) were ranged between 0.06 µg/kg and 135 µg/kg, and for the majority of the pesticides the LOQ were below the regulatory maximum residue limits. Most recoveries at 10 µg/kg and 100 µg/kg were in the range 70%–120% indicating satisfactory accuracy. The validated method was applied to commercial herbal and fruit infusion products detecting chlorpyriphos, DEET, tebuconazole, terbuthylazine, piperonyl butoxide, biphenyl, pendimethalin, pirimiphos-methyl and p,p’-DDE in more than 100 samples from 1,466 so risk assessment on human health was calculated specially for those pesticides.