Nghiên cứu ứng dụng phương pháp LC- MS/MS phân tích đồng thời dư lượng một số hóa chất bảo vệ thực vật nhóm cúc tổng hợp sử dụng phổ biến trong rau ăn lá, quả

A high specificity, sensitivity and reliable reversed-phase LC-MS-MS method was successfully developed for
simultaneous determination of cyhalothrin (CYHA), cypermethrin (CYPER), permethrin (PER), deltamethrin (DELTA),
cyfluthrin (CYFLU) in real vegetable samples with the following optimized conditions: column Agilent Poroshell 120
Phenyl – Hexyl (150 mm x 4.6 mm x 2.7 µm), the isocratic mode of mobile phases including MeOH – CH3COONH4
5 mM in water (99 : 1); the flow rate 0.7 ml/min; sample injection volume 10 μl; Electrospray ionization source was
operated in positive mode and multi reaction monitoring (MRM) mode using the transition of m/z 523.02 → 281, m/z 467.3 → 225, m/z 435.2 →193, m/z 416 →191, m/z 393.3 → 281 were used to quantify CYHA, CYPER, PER, DELTA and CYFLU, respectively. This method was validated basing on EC-657/2002 guideline to meet all the requirements of wide linearity range of 0.5-150 ppb, high correlation coefficients (R2 > 0.997), very good accuracy (recovery rate 85-105.1%) and intermediate precision (RSD% < 8 %), typical LOD, LOQ values of 0.005-0.5 ppb and 0.015- 0.15 ppb for five pyrethroid pesticides. The validated method was used in a 54 real samples survey. The results revealed that 36 vegetable samples (66.67%) contain target pesticide residues below MRLs. Particularly, M.07, M.14 and M.23 samples found permethrin in high levels 1.97, 2.76, 3.6 ppm, respectively, higher the Vietnam Ministry of Health s MRLs.
Keywords: Cyhalothrin, cypermethrin, deltamethrin, QuEChERS, recovery.

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