Study On Establishment And Application Of QuEChERS Combined With GC-MS/MS For Detection Of Pesticide Residues In Nuts And Fruits

Nuts,such as hazelnuts,pine nuts,pecans,almonds,and fruits,such Nanguo pears,wild grapes,cherries and so on,are famous as the special local products of Dongbei,which play an important role in the local economy.However,they are easily attacked by various pests and diseases during the growth stage.In order to ensure the production,the use of pesticides is inevitable,and there is a hidden danger of pesticide residues.Therefore,it is of great significance to establish a simple,efficient,sensitive and practical method for pesticide residue analysis.In this paper,QuEChERS combined with gas chromatography-tandem mass spectrometry were employed to detect 70 pesticides in nuts and 105 pesticides in fruits.The outcomes are as follows.1.A multi-residue analytical method was developed for the determination of 70pesticides in nuts by QuEChERS-GC-MS/MS.The sample was extracted by 1%acetic acid acetonitrile and purified by PSA and C₁₈,and determined by gas chromatography-tandem mass spectrometry.The result implis that all the linear relationships are good in the concentration ranges from 5?g/L to 100?g/L with correlation coefficients greater than 0.99.The limit of detection?S/N=3?are in the range of 0.001?g/kg¹.604?g/kg,the limit of quantification?S/N=10?are in the range of 0.003?g/kg⁵.348?g/kg.The recoveries are determined at three spiked levels of 15?g/kg,30?g/kg,75?g/kg in five samples.The recovery rates of 70pesticides in hazelnut ranged from 68.17%¹09.33%,with the relative standard deviation?RSD?ranged from 0.16%¹1.37%.The recovery rates of 70 pesticides in pine nut ranged from 66.77%¹13.33%,with the relative standard deviation?RSD?ranged from 0.10%¹2.16%.The recovery rates of 70 pesticides in walnut ranged from 66.89%¹05.60%,with the relative standard deviation?RSD?ranged from 0.59%¹0.80%.The recovery rates of 70 pesticides in almond ranged from68.00%¹20.00%,with the relative standard deviation?RSD?ranged from 0.10%¹0.55%.The recovery rates of 70 pesticides in peanut ranged from 67.60%¹19.83%,with the relative standard deviation?RSD?ranged from 0.13%¹2.42%.2.A multi-residue analytical method was developed for the determination of 105pesticides in fruits by QuEChERS-GC-MS/MS.The pear and apple samples were extracted by acetonitrile and purified by PSA,then determined by gas chromatography-tandem mass spectrometry.The grape and cherry samples were extracted by acetonitrile and purified by PSA and GCB,then determined by gas chromatography-tandem mass spectrometry.The result implis that all the linear relationships are good in the concentration ranges from 5?g/L to 100?g/L with correlation coefficients greater than 0.99.The limit of detection?S/N=3?are in the range of 0.05?g/kg¹.50?g/kg,the limit of quantification?S/N=10?are in the range of 0.18?g/kg⁵.00?g/kg.The recoveries are determined at three spiked levels of 10?g/kg,20?g/kg,50?g/kg in four samples,the recovery rates and the relative standard deviation?RSD?of the method range from 77.23%to 116.17%and from 0.01%to7.89%,respectively.