Abstract: Objective: A method for the determination of 11 common pesticides in Rosa roxburghii Tratt. was established using QuEChERS (quick, easy, cheap, effective, rugged, and safe) extraction and ultra-high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). Methods: The QuEChERS conditions were optimized by performing spiked recovery tests. Acetonitrile was used for extraction, and primary secondary amine (PSA) and graphitized carbon black (GCB) were used for purification. The chromatographic separation was achieved using gradient elution with a mobile phase consisting of 0.1% formic acid water and acetonitrile at a flow rate of 0.4 mL/min. In the positive ion mode using an electrospray ionization source, the fragmentor voltage, collision energy and ion pairs for each pesticide were optimized to obtain the best response, and the pesticides were quantified by matrix-matched calibration. Results: The limits of detection (LODs) for all pesticides were in the range of 1.31–8.56 μg/kg, and the limits of quantitation (LOQs) ranged from 4.13–43.57 μg/kg. The correlation coefficients (R) of the calibration curves were in the range of 0.991 2–0.999 9. The average recoveries at three spiked levels ranged from 84.5% to 103.8% (n = 6) with relative standard deviations (RSDs) of 1.2%–8.5%. Conclusion: This method was rapid, sensitive and precise, and could provide technical support for the determination of pesticide residues in R. roxburghii.

Key words: Rosa roxburghii; quick, easy, cheap, effective, rugged, and safe; ultra-high performance liquid chromatography-tandem mass spectrometry; pesticide residues