To establish a method for the determination of residual levels of 6 kinds of novel pesticides (flutianil, ipflufenoquin, mandestrobin, benzpyrimoxan, pyriofenone and pyflubumide) in plant-derived foods by gas chromatography-tandem mass spectrometry (GC-MS/MS).
Samples were extracted by shaking with 1% formic acid in acetonitrile. Anhydrous magnesium sulfate, sodium chloride, citric acid dihydrate and disodium citrate sesquihydrate were then added to the extract; after shaking, the mixture was centrifuged. A quantitative volume of the supernatant was purified using the QuEChERS method, with the purification materials including anhydrous magnesium sulfate (MgSO4), primary secondary amine, octadecyltrimethoxysilane and graphitized carbon black. After vortex mixing and centrifugation, 2 mL of the supernatant was transferred to a centrifuge tube, concentrated to near dryness under nitrogen, dissolved in 1 mL of n-hexane, and filtered through an organic phase filter membrane before GC-MS/MS analysis. Quantification was performed using a matrix-matched standard curve. In this study, the sample extraction, purification and determination procedures were optimized and discussed.
For the 6 kinds of novel pesticides (including flutianil and ipflufenoquin) in plant-derived foods, the limits of quantitation ranged from 0.005 mg/kg to 0.050 mg/kg, the recoveries were between 71.1% and 119.7%, and the relative standard deviations were 0.6% to 12.8%.
This method is simple, rapid and accurate, and is suitable for the analysis and detection of multi-residues of the 6 kinds of novel pesticides in plant-derived foods.
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |