Determination Of Residues Of Carbamate Pesticides On Ginkgo Biloba By Ultra Performance Liquid Chromatography/Mass Spectrometry

Ginkgo leaves, which contain flavonoid glycosides and ginkgolides, have biologicalactivity and pharmaceutical value. They can improve cardiovascular function, resist tomemory loss and senile dementia. However, as for insects and pathogens damage, the yield ofginkgo leaves are gradually decreasing. So pesticides are widely used on ginkgo to protect theplants from damage and infestation. Nowadays, pesticide residues have caused more concern.With the improvement of the foreign technical barriers, especially after the implementation ofJapanese Positive List, ginkgo leaves to export require higher standards. Therefore, it hasgreat significance to strengthen the detection techniques of pesticide residues in ginkgo leaves.This paper studied the extraction, purification and UPLC-MS conditions of common15kinds of carbamate pesticides in ginkgo leaves, and developed solid phase extraction-ultraperformance liquid chromatography/tandem mass spectrometry to detect them. The mainresult are as follows：1. Study and optimize the instrument conditions. We optimized the chromatography andMS conditions, then successfully established the qualitative ions and quantitative ions, andchose the suitable chromatographic column: XTerra MS C₁₈column （150mm×2.1mm,3.5μm）, the column temperature is:40℃, the flow rate is:0.3mL/min, and gradient elution.Mass spectrometry conditions are as follows: electrospray ionization ion source ESI（+）,multiple reaction monitoring mode （MRM）, capillary voltage was3.0KV, ion sourcetemperature was110℃, desolvation temperature was400℃, desolvation gas flow was500L/hr, cone gas flow was80L/hr. The separation was achieved by ultra performance liquidchromatography, and the identification and quantification were performed by MS/MS withmultiple reaction monitoring （MRM） and electrospray ionization in positive mode. Thecalibration curves showed good linearity in the range of20-500μg/L with correlationcoefficient of0.9962-0.9999.2. Optimize sample preparation of pesticides residues on ginkgo leaves. Extractionsolvent, the dosage of extraction solvent, sorbent, elution solvent and the dosage of elutionsolvent were optimized. And the final method of preparation for SPE sample was as follows: homogeneous extracted with30mL acetonitrile, then purified by TPT column and eluted by25mL acetonitrile: toluene （3:1, v/v）, and the elution solvent was evaporated to drynessbefore dilution in1mL acetonitrile, and finally was injected into the UPLC-MS/MS system.The approach is easy to operate, fast to finish and in line with the technical requirements ofpesticide residues on multi-residue detection.3. Analysis of recoveries and precision experiments. The recoveries of the15carbamatepesticides on ginkgo leaves （4,10,20and40g/kg） ranged from65.22%to96.60%, with therelative standard deviations （RSD） from1.43%to10.06%.The method is sensitive and accurate. It can meet the requirements of the pesticideresidue analysis and provided technical support of export inspections of Ginkgo leaves.