Abstract:

The purpose is to establish an analytical method for the determination of the nine fungicides (such as sedaxane and benzovindiflupyr) residues in Carthamus tinctorius using QuEChERS pretreatment combined with triple quadrupole gas chromatography-tandem mass spectrometry (GC-MS/MS). After the sample was subjected to hydration treatment, samples were extracted with acetonitrile, and purified by QuEChERS. The sample solution was separated on an HP-5 MS capillary column (30 m×0.25 mm, 0.25 μm) and analyzed in multiple reactions monitoring (MRM) mode, with quantification performed by matrix-matched internal standard method. This method enabled rapid extraction and high-sensitivity determination of the nine fungicides in C. tinctorius. The mass concentrations of the nine fungicides showed a linear correlation with the chromatographic peak areas in the range of 5-500 μg/L, with correlation coefficients (R²) of 0.9998-0.9999. The method detection limit (MDL) ranged from 0.0008-0.0053 mg/kg, and the method quantification limit (MQL) ranged from 0.0027-0.0169 mg/kg. The average recoveries at three spiked levels (high, medium and low) ranged from 75.58% to 89.95%, and the relative standard deviations of the determination results were 0.27%-8.43% (n=6). This method features simple pretreatment, accurate quantification, and high sensitivity, meeting the requirements for pesticide residue detection and analysis, and can provide reliable technical support for quality and safety control of C. tinctorius and residual risk monitoring of the nine fungicides.

Key words: QuEChERS, GC-MS/MS, Carthamus tinctorius, fungicides, sedaxane, matrix effect