QuEChERS技术在气相色谱法测定龙安柚和豇豆中有机磷类农药残留回收率初探OA

QuEChERS pretreatment technology offers a fast and convenient approach,reducing both labor costs by 50%and the consumption of hazardous chemical reagents by 70%.These advantages make it particularly suitable for county-level institutions.To develop an accurate and efficient pretreatment method for pesticide residue determination in fruit and vegetable samples suitable for county-level laboratories,a spike-and-recovery experimental design was employed.Recovery rate is the primary indicator for assessing analytical accuracy.Two representative matrices were selected:Longan pomelo(a Geographical Indication product from Guang'an City)for fruit,and cowpeas for vegetables.Spike-and-recovery experiments were designed separately on each matrix.The QuEChERS pretreatment technique was used to determine the recovery rates of seven organophosphate pesticide residues in Long'an pomelo by gas chromatography.The common interference peaks in chromatography,namely omethoate and diazinon,were qualitatively analyzed using a dual-column system,and the recovery rate data was compared with mass spectrometry data.Then,the recovery rate data of 16 organophosphate pesticide residues in cowpea determined by gas chromatography using QuEChERS pretreatment technology were provided for assessing method accuracy.The results showed that QuEChERS pretreatment technology yielded satisfactory recovery rates for 7 organophosphate pesticide residues in Long'an pomelo and 16 in cowpea by gas chromatography.The recovery rates of 7 pesticides in Long'an pomelo ranged from 94.5%to 97.5%,with RSD of 1.7%to 3.2%.The recovery rates of 16 pesticides in cowpea ranged from 89.0%to 104.5%,with RSD of 1.3%to 8.4%.