1、固相萃取-气相色谱串联质谱法检测牛奶中41种农药残留张月辉(辽宁省检验检测认证中心,辽宁 沈阳 110032)摘 要:目的 建立固相萃取-气相色谱串联质谱法(SPE-GC-MS/MS)同时测定牛奶中41种农药残留分析方法。方法 采用固相萃取方法对样品进行前处理。样品经乙腈提取、盐析后,提取液经Captiva EMR-Lipid 固相萃取柱净化后上机测定。用气相色谱-三重四极杆串联质谱仪进行多农残检测。结果 41种农药在501000 ng/ml之间呈良好的线性关系,相关系数r均大于0.99。在0.02,0.1,0.2 mg/kg加标水平下,41种农药的平均回收率为60.6%110.6%,相对标准
2、偏差(RSD)为1.3%16.6%(n=6)。结论 该方法选择性好,操作简单安全,快速准确,适用于牛奶中多种农药残留的测定。关键词:固相萃取;气相色谱-串联质谱法;农药残留;牛奶中图分类号:O657.7 TS252.41 文献标识码:A 文章编号:1672-979X(2023)01-0046-06DOI:10.3969/j.issn.1672-979X.2023.01.009Simultaneous Determination of 41 Pesticide Residues in Milk by Solid-phase Extraction and Gas Chromatography-ta
3、ndem Mass SpectrometryZHANG Yue-hui(Liaoning Inspection,Examination and Certification Centre,Shenyang 110015,China)Abstract:Objective To establish a method for the simultaneous determination of 41 pesticide residues in milk by solid-phase extraction and gas chromatography-tandem mass spectrometry.Me
4、thods The sample was pretreated by solid-phase extraction.The sample was extracted with acetonitrile,and after salt extraction,the extracting solution was purified by Captiva EMR-Lipid solid-phase extraction.The pesticide residues were determined by gas chromatography-triple quadrupole mass spectrom
5、etry.Results There were good linear relationships between 50-1000 ng/ml for the pesticide residues and the correlation coefficients were greater than 0.99.At 0.02,0.1,0.2 mg/kg,the average recoveries of 41 pesticides were 60.6%-110.6%,and the relative standards(RSDs)were 1.3%-16.6%(n=6).Conclusion T
6、he method is of high sensitivity,accurate,safe,simple and suitable for determination of pesticide residues in milk.Key Words:solid-phase extraction;gas chromatography-tandem mass spectrometry;pesticide residue;milk收稿日期:2021-10-11基金项目:辽宁省自然科学基金指导计划(编号:2019-ZD-0847)作者简介:张月辉,副主任技师,研究方向:食品农残检测,E-mail:牛奶
7、是一项重要饮品,日常饮用益于身体健康。为了提高我国食品监测能力,保护消费者健康,有必要针对牛奶中农药建立先进的分离和检测方法,加强对牛奶品质的监测。目前,检测乳制品的方法有气相色谱法1-2、气相色谱-质谱法3-7、液相色谱法8-10、液相色谱串联质谱法等11-12,研究重点主要集中在前处理方面。因牛奶中的脂肪含量高,基质较复杂,如何有效除杂又能保持农残检测的高灵敏度是检测技术的重点。GB/T 23210-200813和GB/T 23211-200814中分别规定了牛奶中511种和493种农药的测定方法。杨国良等15采用固相萃取处理牛奶中的有机氯类农药,邓小娟等16采用QuEChERS 处理牛奶
8、中的拟除虫菊酯类农药。这两种前处理方法操作简单,但除脂能力仍然有46 食品与药品 Food and Drug 2023年第25卷第1期限。总体上,国内在牛奶农药残留的检测方面,存在前处理操作繁琐、试剂消耗量大、脂肪不能完全除去等问题。与传统的气相色谱串联质谱法(GC-MS)相比,三重四极杆串联质谱具有极高的选择性、极强的抗干扰能力、高灵敏度和高通量离子传输效率及准确定量等特点,使该技术在复杂基质背景下仍能完成目标物的准确鉴定。本实验旨在建立牛奶中41种农药残留的固相萃取方法,前处理方法采用除脂能力强的Captiva EMR-Lipid 固相萃取柱,采用气相色谱串联质谱法测定。本法能有效除去脂肪
9、,操作简便高效,结果准确,灵敏度高。1 材料与方法1.1 仪器与材料Agilent7890B-7000C气相色谱串联质谱仪(安捷伦公司);Heraeus Multifu.ge X1R离心机(赛默飞世尔公司)。乙腈、丙酮(色谱纯,Fisher公司);QuEChERS提取盐包(安谱公司);固相萃取柱:Captiva EMR-Lipid 固相萃取柱(安捷伦公司);实验室用水为自制超纯水。42种农药对照品见表1。表1 42种农药对照品名称序号名称序号名称序号名称序号名称1二苯胺12甲霜灵23嘧菌环胺34吡丙醚2氟铃脲13甲基嘧啶磷24噻螨酮35伏杀硫磷3甲拌磷14毒死蜱25三唑醇36高效氯氟氰菊酯4治
10、螟磷15马拉硫磷26杀扑磷37氯苯嘧啶醇5西玛津16三唑酮27乙氧氟草醚38蝇毒磷6地虫硫膦17苯硫威28噁霜灵39氟氯氰菊酯7嘧霉胺18丙溴磷29苯霜灵40氯氰菊酯8抗蚜威19虫螨腈30吡草醚41醚菊酯9精甲霜灵20多效唑31丙环唑42环氧七氯(内标)10甲基毒死蜱21二甲戊灵32溴螨酯11甲基立枯磷22甲苯氟磺胺33亚胺硫磷注:对照品来源为德国Dr.E公司,纯度均大于97%。1.2 方法1.2.1 标准溶液的配制 41种农药标准混合溶液:准确称取41种农药对照品适量,用丙酮溶解并稀释,配制成浓度为10 g/ml的标准混合溶液。环氧七氯标准溶液:准确称取适量环氧七氯对照品,用丙酮溶解并稀释,
11、配制成浓度为10 g/ml环氧七氯标准溶液。基质标准曲线的制备:分别准确量取41种农药标准混合溶液适量,用丙酮溶解并稀释,配成浓度为50,100,250,500,1000 ng/ml混合标准系列溶液。准确移取各浓度标准系列溶液1 ml分别添加至5份经前处理氮气吹干后的的空白样品中,然后加入环氧七氯标准溶液100 l,涡旋混匀,得到50,100,250,500,1000 ng/ml浓度的系列基质标准溶液。1.2.2 样品前处理 称取约5 g样品,置入50 ml塑料离心管,加10 ml水涡旋混匀,静置30 min。加入10 ml乙腈,加入提取盐包和陶瓷均质子,盖上离心管盖,剧烈震荡5 min,80
12、00 r/min离心5 min。取5 ml乙腈上清转移至Captiva EMR-Lipid固相萃取柱中,收集流出液,40 水浴中氮气吹至近干。用1 ml丙酮复溶,再加入100 l环氧七氯标准溶液,混匀,用微孔滤膜过滤,上机测定。1.2.3 仪器条件 色谱柱:HP-5(30 m0.25 mm,0.25 m);柱温:以60 为起始温度,保持1 min,以40/min速率升温至170,以10/min速率升温至310,保持3 min;汽化室温度:230;载气流速:1.0 ml/min,进样量:1 l。扫描方式:MRM;离子源:EI源;接口温度:280;离子源温度:230。2 结果与分析2.1 质谱参数
13、质谱参数见表2。2.2 线性范围与定量结果见表3。食品与药品 Food and Drug 2023年第25卷第1期 47表2 农药化合物质谱参数编号化合物前体离子(m/z)子离子(m/z)碰撞能量/V编号化合物前体离子(m/z)子离子(m/z)碰撞能量/V1二苯胺169.0168.21522甲苯氟磺胺136.991.120168.0167.215237.9137.015167.0166.220136.965.0302氟铃脲176.0148.02023嘧菌环胺225.2224.310279.0178.015224.2208.220226.2225.3103甲拌磷121.065.01024噻螨酮1
14、1.159156.0155.0121.047.03011.159184.0149.0128.965.01511.159227.0149.04治螟磷201.8145.91025三唑醇128.065.025237.8145.910168.070.010321.8201.910128.0100.0105西玛津201.1173.1526杀扑磷144.985.05173.0172.15144.958.115173.0138.2585.058.056地虫硫膦136.9109.0527乙氧氟草醚252.0196.020108.980.95252.0146.030108.962.915299.9222.815
15、7嘧霉胺198.0183.11528噁霜灵163.0132.15198.0118.135163.0117.125198.0158.120132.0117.1158抗蚜威238.0166.21029苯霜灵148.0105.120166.055.120148.077.035166.096.015266.0148.159精甲霜灵192.0160.1530吡草醚412.0349.010160.0145.110349.0307.015160.0130.120338.9288.91510甲基毒死蜱124.947.01531丙环唑172.9145.015124.978.95172.9109.030285.9
16、92.920172.974.04511甲基立枯磷265.0250.01532溴螨酯183.0155.015265.093.025185.0157.015124.947.015338.8182.92012甲霜灵220.0192.1533乙螨唑160.077.120234.0146.120160.0133.110234.0174.110160.0105.01513甲基嘧啶磷290.0125.02034吡丙醚136.178.120232.9151.05136.196.015232.9125.05321.0222.01014毒死蜱196.9169.01535伏杀硫磷182.0111.015198.9171.015182.0102.115313.8257.815182.075.13015马拉硫磷126.999.0536高效氯氟氰菊酯208.0181.05172.999.015197.0141.010157.8125.05181.1152.02548 食品与药品 Food and Drug 2023年第25卷第1期表3 定量限和线性方程序号保留时间/min化合物定量限/mgkg-1线性方程 r序号