张建莹,邓慧芬,李月梅,林 珊,岳振峰,吴卫东
(深圳出入境检验检疫局 食品检验检疫技术中心,广东 深圳 518045)
QuEChERS/超高效液相色谱-串联质谱法测定果蔬中122种香港规例农药残留
张建莹*,邓慧芬,李月梅,林 珊,岳振峰,吴卫东
(深圳出入境检验检疫局 食品检验检疫技术中心,广东 深圳 518045)
应用改进的QuEChERS法结合超高效液相色谱-串联质谱仪,建立了水果、蔬菜中122种中国香港《食物内除害剂残余规例》农药残留的测定方法。分析物采用电喷雾离子源,正、负离子多反应监测(MRM)模式,基质匹配外标法定量。122种农药在0.010~0.20 mg/L 浓度范围内呈良好线性关系,其线性相关系数(r)不小于 0.99,方法的定量下限为0.010 mg/kg;3个加标水平的回收率为60%~110%;相对标准偏差(RSD)为1.8%~19.4%。该法快速简便,耗时短,灵敏度高,稳定性好,用于日常供港果蔬食品中农残检测可显著降低检测成本。
QuEChERS;超高效液相色谱-电喷雾串联质谱;农药残留
2014年8月1日,中国香港特区政府正式实施《食物内残余除害剂规例》(简称《规例》),对出口至香港的食品实施严苛的农药检测。该法规涉及360种除害剂、7083个限量标准,包含584种(类)食品、农产品[1];该法规很多限量远低于GB 2763-2016《食品安全国家标准 食品中农药最大残留限量》[2]。中国内地是香港特区食品的主要供应地,占香港进口总量的90%以上。《规例》的实施直接影响内地每年约47亿美元供港食品农产品的通关效率和经济效益,同时对供港食品提出了更高的质量安全要求,特别对供港食品农药残留检测技术提出了巨大挑战。鉴于目前我国缺乏针对《规例》农药的高通量定量检测技术,为了满足内地输港蔬菜检验工作的实际需求,迫切需要建立蔬菜、水果中可同时检测上百种除害剂多残留的高通量定量检测方法。
农药残留的主要检测方法有气相色谱(GC/ECD)、气相色谱-质谱(GC-MS)和气相色谱-串联质谱(GC-MS/MS),检测对象包括牛奶、果酒饮料、果蔬、粮谷等,其中适用于果蔬中农药多残留的标准检测方法有GB/T 19648-2006,GB/T 20769-2008,NY/T 761-2008,NY/T 1379-2007,EN 15662:2008和AOAC 2007.01等[3-8]。关于果蔬中农药多残留检测的文献很多[9-18],但尚未见有针对或涵盖香港《规例》上百种农药多残留的高通量定量检测方法报道。潘孝博等[18]建立了液相色谱-四极杆串联飞行时间质谱法测定食品中249种香港《规例》农药残留的筛查方法,该方法中65%农药的定量下限达到0.010 mg/kg,但较多农药的加标回收率低于50%,只能作为筛查和确证方法。QuEChERS方法的步骤少,目标化合物损失少,试剂消耗少,经济环保,快速高效,适合的样品基质及农药种类多,已成为多残留分析的首选方法。而LC-MS/MS技术具有灵敏度高、选择性强的优点,在复杂基质下能完成痕量目标化合物的定性定量分析。本文通过参考国际方法EN 15662:2008[7]和AOAC 2007.01[8],改进前处理方法(采用1%乙酸-乙腈溶液提取目标化合物,经改进的QuEChERS法净化),建立了超高效液相色谱-串联质谱(UPLC-MS/MS)测定供港果蔬中122种香港《规例》农药残留量的方法。本方法的建立将在监管范围、检测技术和时效性等多方面提升供港果蔬食品的保障水平和力度。
1.1 仪器与试剂
超高效液相色谱UPLC、Xevo-TQS四极杆串联质谱仪(美国Waters公司);均质仪(美国Omni公司);涡旋振荡仪(德国Heidolph公司);高速冷冻离心机(德国Sigma公司);高纯水发生器(美国Millipore公司);0.22 μm有机滤膜。
甲醇、乙腈、正己烷、甲酸、乙酸铵(色谱纯,德国Merck公司),无水MgSO4、NaCl均为分析纯;实验用水为Milli-Q超纯水;N-丙基乙二胺吸附剂(PSA)、十八烷基键合硅胶吸附剂(C18)(美国Supelco公司)。122种《规例》农药标准品名单见表1(纯度≥95%,德国Dr.E公司)。根据标准品的溶解度选用甲醇、乙腈或丙酮等溶剂配制浓度为1 000 mg/L的各农药标准储备液,再以乙腈配制成10 mg/L的混合标准溶液(-18 ℃避光存放)。
1.2 样品处理
称取试样10 g,加入3 mL水和10 mL 1%(体积分数)乙酸-乙腈溶液,均质提取1 min,9 500 r/min 离心5 min。吸取全部上清液于15 mL离心管,加入2 g NaCl,涡旋振荡30 s,9 500 r/min 离心5 min。吸取上清液5 mL,加入900 mg MgSO4、150 mg PSA、150 mg C18,涡旋振荡30 s,9 500 r/min 离心5 min。取1 mL上清液,过0.22 μm有机滤膜,供液相色谱-串联质谱仪测定。
1.3 色谱条件
色谱柱:Acquity BEH C18,1.7 μm,50 mm×2.1 mm(i.d.)(美国Waters公司)。流动相:A为0.005 mol/L乙酸铵溶液(含0.1%甲酸),B为甲醇(含0.1%甲酸)。梯度洗脱程序:0~0.5 min,5%B;0.5~7.0 min,5%~60%B;7.0~9.0 min,60%~95%B;9.0~12.0 min,95%~100%B;12.0~14.0 min,100%B;14.0~14.1 min,100%~5%B;14.1~16.0 min,5%B。流速:0.3 mL/min。进样量:2 μL。
1.4 质谱条件
离子化模式:电喷雾离子源(ESI),温度:150 ℃;正离子和负离子分别扫描;质谱扫描方式:多反应监测(MRM);去溶剂温度:500 ℃;去溶剂气流速:900 L/h;毛细管电压:0.8 kV(正离子组)或-1.5 kV(负离子组);锥孔电压:30 V(正离子组)或-30 V(负离子组);分辨率:单位分辨率;驻留时间:30 ms。其它质谱参数见表1。
表1 122种化合物测定的质谱参数Table 1 Mass parameters for the detection of 122 compounds
(续表1)
No.CompoundParentionDaughterionsCone(V)CE(eV)62Cyromazine(灭蝇胺)167.060.0*,85.02919,1863Naptalam(萘草胺)292.1144.1*,149.1119,2264Prometryn(扑草净)242.0158.0*,200.12640,2765Triforine(嗪氨灵)456.9353.9*,411.91619,1366Metribuzin(嗪草酮)215.089.0*,125.04120,1867Metaflumizone(氰氟虫腙)507.1177.9*,287.94029,2268Clodinafop-propargyl(炔草酸)349.991.0*,266.03025,1069Clothianidin(噻虫胺)250.0132.0*,169.02418,1270Thiacloprid(噻虫啉)253.090.1*,126.03245,4571Thiamethoxam(噻虫嗪)292.0132.0*,211.22822,1272Thiabendazole(噻菌灵)202.0125.0*,175.04238,3573Buprofezin(噻嗪酮)306.057.0*,201.02426,2274Trifloxysulfuron(三氟啶磺隆)438.0139.0*,182.03045,2075Tricyclazole(三环唑)190.0136.0*,163.04137,3276Tralkoxydim(三甲苯草酮)330.2138.1*,284.33119,1377Triadimenol(三唑醇)296.069.9*,126.93032,3678Triadimefon(三唑酮)294.169.3*,197.23120,1579Oxamyl(杀线威)237.072.0*,90.01221,1080Diclosulam(双氯磺草胺)406.1161.0*,378.04630,1581Mandipropamid(双炔酰菌胺)412.1328.1*,356.14515,1082Propamocarb(霜霉威)189.174.0*,102.03140,3683Cymoxanil(霜脲氰)199.0111.0*,128.01415,884Tetraconazole(四氟醚唑)372.070.1*,159.04120,3085Aldicarb(涕灭威)213.089.0*,116.03016,1186Desmedipham(甜菜安)301.0136.0*,182.03422,1087Carboxin(萎锈灵)236.087.0*,143.02522,2088Trifloxystrobin(肟菌酯)409.0145.0*,186.03455,3589Tebuconazole(戊唑醇)308.070.1*,125.04040,2290Sethoxydim(烯禾啶)328.0178.0*,282.03422,1091Dimethomorph(烯酰吗啉)388.1165.0*,300.94130,2092Diniconazole(烯唑醇)326.170.2*,159.04625,3493Mesotrione(硝磺草酮)340.1104.0*,228.12332,1894Phoxim(辛硫磷)299.097.0*,129.02034,2695Nicosulfuron(烟嘧磺隆)411.0106.0*,182.03232,2296Omethoate(氧乐果)214.1125.1*,183.12622,1197Difenzoquat(野燕枯)249.2118.2*,130.13539,5398Metconazole(叶菌唑)320.170.0*,125.03822,3699Isoprocarb(异丙威)194.195.1*,137.11514,8100Clomazone(异草酮)240.089.0*,125.03250,35101Imazalil(抑霉唑)297.069.0*,159.03032,35102Indoxacarb(茚虫威)528.0150.0*,249.04245,30103Ametryn(莠灭净)228.168.1*,186.13250,35104Atrazine(莠去津)216.196.1*,174.02923,28105Piperonyl-butoxide(增效醚)356.3119.0*,176.92637,25106Ipconazole(种菌唑)334.170.2*,125.03542,22107Fenobucarb(bpmc,仲丁威)208.095.0*,152.02214,8108Imazosulfuron(唑吡嘧磺隆)413.0152.8*,155.91612,18109Carfentrazone-ethyl(唑草酮)411.9345.9*,384.05224,12110Fenpyroximate(唑螨酯)422.2138.1*,366.13232,25111Flumetsulam(唑嘧磺草胺)326.1109.0*,129.04650,25112Flufenpyr-ethyl(氟哒嗪草酯)409.0307.0*,335.02028,20113Flufenoxuron(氟虫脲)489.1141.0*,158.04046,22114Spirotetramat(螺虫乙酯)374.0302.0*,330.06623,25115Diflubenzuron(除虫脲)#309.0150.9*,288.9-30-22,-11116Teflubenzuron(氟苯脲)#378.9195.7*,338.7-35-24,-13117Flubendiamide(氟苯虫酰胺)#680.9253.8*,273.9-10-30,-16118Fomesafen(氟磺胺草醚)#437.0195.0*,332.0-42-40,-13119Chlorbenzuron(灭幼脲)#307.0125.9*,154.0-35-26,-11120Flonicamid(氟啶虫酰胺)#228.081.1*,146.0-40-14,-30121Acifluorfen(三氟羧草醚)#360.2194.9*,315.9-45-28,-12122Fluazinam(氟啶胺)#437.0195.0*,332.0-42-40,-13
*quantitative ion;# negative ion
2.1 基质效应
基质效应是质谱检测中普遍存在的现象。液质联用法的基质效应一般表现为基质抑制效应。基质效应的消除有如下方法:①在前处理时尽可能将样品处理干净;②在仪器分析时采用基质匹配标准溶液作校准曲线;③采用内标法进行校正。因本方法涉及的农药品种较多,同位素内标法不太现实,而采用性质相近的物质作为内标会存在一定偏差;因此本方法采用基质匹配标准液作校准曲线以消除基质效应。
2.2 提取溶剂的选择
由于这122种《规例》农药的极性差异较大,因此提取溶剂的选择要考虑溶剂性质、农药性质和基质特点。本实验选取1%乙酸乙腈、乙腈、丙酮和乙酸乙酯作为提取溶剂,对比考察了其对蔬菜、水果样品中122种目标化合物的提取效果。实验发现,加入乙酸乙酯的样品浑浊且没有明显的分层效果,共萃取物较多。乙酸乙酯对有机磷农药的回收率较好,但对其余农药的回收率仅为60%~70%,这是因为乙酸乙酯对水的溶解度较低,无法从含水基质中完全萃取出极性较大的农药。丙酮极性较大,且与水互溶,易将水溶性的极性干扰物(如色素)一并提取出来,使后续的净化步骤难度加大,导致其重复性较差。乙腈的溶解性好,渗透力强,适合的农药极性范围相对广泛,乙腈通过适当的酸化,能促进农药从组织中溶出,改善提取效率。乙腈酸化后,辛硫磷的回收率可从80%提高到88%,甲草胺的回收率从68%提高到77%,敌瘟磷的回收率从72%提高到80%,灭线磷的回收率从60%提高到82%,吡唑醚菌酯的回收率达76%~87%,氟哒嗪草酯的回收率从75%提高到88%。综合考虑,本实验选择1%乙酸乙腈为提取溶剂。
比较了不同盐析步骤对回收率的影响。①方法一:样品按“1.2”步骤处理;②方法二:试样10 g,加入3 mL水、2 g NaCl和10 mL 1%(体积分数)乙酸-乙腈溶液,均质提取,离心后取上清液按“1.2”步骤净化。比较结果得知,使用方法一处理,部分目标化合物的回收率比方法二处理的回收率高(如甲硫威、甲萘威、噻菌灵、灭蝇胺等,见图1)。这是因为提取溶剂、水和盐同步加入后,部分极性化合物的提取效率降低;而将水和有机溶剂混合相吸取出来,再加NaCl盐析,提取效果更佳。
2.3 净化条件的选择
由于蔬菜、水果等样品基质中含有较多的有机酸、糖类、维生素以及脂肪等物质,这些物质在提取过程中会与被测农药一并提取出来。若不进一步净化,基质效应带来的干扰会影响检测结果的准确性。QuEChERS法常用吸附剂有PSA、C18及石墨化炭黑(GCB)等,可实现对基质中的色素、有机酸、脂肪酸和强阴离子等多种组分的净化。无水MgSO4作为QuEChERS前处理方法的脱水剂,能有效减小水相的体积,从而促进水相中的极性化合物再分配进入有机相中,故其加入量会影响试样的脱水效果,进而影响后续净化剂的吸附效果。PSA具有弱的阴离子交换能力,通过氢键和化合物作用,可除去脂肪酸、部分有机酸、糖和色素。C18吸附剂是在硅胶基质上接有十八烷基,具有较高的相覆盖率和碳含量,对非极性物质有较高的容量,对油脂的去除效果十分显著,还可除去一些非极性杂质。GCB对平面结构分子(如多菌灵和部分氨基甲酸酯类农药)具有很强的亲合性,因此本实验不选用该吸附剂。综合考虑,本实验以火龙果为样品基质,在0.100 mg/kg加标水平下,考察了待净化液中不同加入量的无水MgSO4,PSA和C18对目标化合物回收率的影响。
2.3.1 无水MgSO4加入量的影响 分别比较了添加300,500,700,900 mg MgSO4的回收效果。结果表明,大部分目标化合物的回收率无变化,但个别化合物在无水MgSO4加入量为900 mg时,回收率达到最大;继续增大无水MgSO4的加入量,则会吸附目标化合物,导致提取效率降低。故本实验采用无水MgSO4的添加量为900 mg。
2.3.2 PSA吸附剂加入量的影响 分别比较了添加50,100,150,200 mg PSA的回收率。结果表明,PSA添加量为50 mg和100 mg时,122种农药的最低回收率分别为67.1%和71.3%。而PSA添加量为150 mg 时,122种农药的平均回收率最好,其回收率为83.3%~119%。
2.3.3 C18吸附剂加入量的影响 C18吸附剂对非极性的组分有吸附作用,可去除提取液中甾醇类干扰物、脂肪酸、烯烃类干扰物及色素。比较了分别添加50,100,150,200 mg C18的回收率。结果表明,C18添加量为150 mg时,122种农药的平均回收率最好,其回收率为85.5%~114%。
本实验最终确定无水MgSO4,PSA,C18的用量分别为900,150,150 mg。
2.4 UPLC-MS/MS条件的优化
为了达到最佳的色谱分离和质谱响应,实验对比了5种流动相:甲醇(含0.05%甲酸)-0.005 mol/L乙酸铵(pH 3.0),甲醇(含0.1%甲酸)-0.005 mol/L乙酸铵(含0.1%甲酸),甲醇(含0.1%甲酸)-0.1%乙酸,甲醇(含0.1%甲酸)-水,乙腈(含0.1%甲酸)-0.05%甲酸的色谱分离效果。实验结果显示,在流动相中加入少量甲酸(0.1%)有利于提高分析物的离子化效率并改善色谱峰峰形,而加入乙酸铵可起到缓冲盐的作用。最终实验确定以甲醇(含0.1%甲酸)-5 mmol/L乙酸铵(含0.1%甲酸)作为流动相,并优化确定了最佳洗脱程序(见“1.3”)。实验结果显示,在优化条件下,122 种目标化合物均可得到较好的分离度和峰形,114种农药(正离子)和8种农药(负离子)的MRM总离子流图见图2。
2.5 方法学验证
2.5.1 方法的线性方程与定量下限 在优化实验条件下,用相应的空白样品基质溶液配成质量浓度为0.010,0.025,0.050,0.10,0.20 mg/L的基质混合标准工作溶液,采用本方法进行测定,以峰面积对标准溶液中各被测组分的浓度绘制工作曲线。结果表明,122种目标化合物在0.010~0.20 mg/L范围内,定量离子的响应峰面积与样液中所含农药的浓度之间呈良好的线性关系,相关系数(r)均不小于0.99(表2)。
基于回收率和相对标准偏差(RSD)满足欧盟SANTE/11945/2015要求的最低试验添加水平[19],以及加标样品的定量离子对色谱信号10倍信噪比(S/N)的要求,并结合国内外残留限量要求,确定了122种目标化合物的定量下限均为0.010 mg/kg。
2.5.2 方法的准确度与精密度 采用空白的火龙果作为验证基体,各农药加标水平为0.010,0.050,0.10 mg/kg,每个水平做6个平行。按本方法进行测定,外标法定量,计算每种农药的回收率及相对标准偏差(见表2)。
表2 122种化合物的线性方程、相关系数、回收率与相对标准偏差(火龙果基质)
Table 2 Regression equations,correlation coefficients(r),recoveries and relative standard deriations of 122 compounds(Pitaya)
No.CompoundRegressionequationrRecovery(%)RSD(%)1AbamectinY=475.11X-768.410.9953109,93.4,85.013.6,7.5,14.42Azinphos-methylY=439.86X+103450.9997103,93.4,80.86.3,2.8,5.93TopramezoneY=1621.5X-3650.10.997771.0,75.2,71.712.0,9.7,3.34DichlofluanidY=4130.8X-142240.9970111,99.3,93.912.2,17.2,12.95Tribenuron-methylY=30983X+1121680.995196.7,93.2,83.911.8,8.8,7.26DifenoconazoleY=23443X-191730.9970114,113,11312.7,8.6,7.57BenalaxylY=22918X-118520.994091.8,88.1,82.84.7,2.4,7.88ZoxamideY=66183X+935130.996696.3,108,89.26.9,2.0,5.09ImidaclopridY=6093.0X+5545.80.998897.0,76.8,74.14.4,7.6,5.710Fluazifop-butylY=7201.4X-7626.30.993597.7,84.1,86.614.9,17.5,14.311PymetrozineY=13176X-247100.997376.2,89.0,84.33.0,2.6,5.512PropiconazoleY=11484X+208880.994795.7,88.9,80.65.1,2.7,6.513PyraclostrobinY=43059X-3667.60.998891.6,90.9,83.25.5,6.8,5.014TebufenozideY=834.28X-3827.40.998560.2,91.8,82.418.3,3.3,6.215PyridateY=5331X-524440.993983.3,104,88.119.0,9.8,17.416PhenthoateY=4309.8X+8444.80.994895.8,90.3,82.05.5,2.0,5.317IsoprothiolaneY=22057X-137260.993886.5,93.2,82.92.4,4.0,5.918TrichlorfonY=20957X-352770.993881.2,94.9,90.67.2,2.2,7.819DiuronY=62276X+2178990.997184.3,93.3,82.14.5,2.1,4.520AnilazineY=488.59X-911.250.9949118,104,97.819.3,1.8,13.221EdifenphosY=39081X-340400.992481.5,90.5,84.94.8,1.9,6.822CarbosulfanY=15380X-257680.9911117,112,91.212.5,8.7,10.423AcetamipridY=2059.2X-2696.70.997495.3,88.3,85.83.2,7.5,8.624CarbendazimY=14985X-685960.998092.5,77.5,71.83.3,4.0,5.225PaclobutrazolY=4140.8X-8310.80.9940104,98.1,88.56.4,3.6,7.826FamoxadoneY=1017.1X-5526.20.9988118,92.0,82.27.2,13.3,8.627DimethenamidY=5742.2X-172660.992285.3,89.9,89.13.4,5.0,7.128PendimethalinY=1373.6X+146370.991498.7,90.7,83.719.0,5.3,8.929ClopyralidY=799.18X+214510.993491.3,81.6,78.815.4,5.9,3.630RimsulfuronY=9103.8X+223920.999495.7,107,87.010.1,9.1,5.631Triflusulfuron-methylY=36276X-532560.995296.7,93.2,83.911.7,8.8,7.232Fluthiacet-ethylY=39448X+5711.20.993075.8,95.6,92.76.9,4.4,7.833FluopicolideY=3987.27X-122960.998285.5,94.7,86.87.4,3.4,7.934FipronilY=24226.4X-2143.00.9986101,107,88.96.4,2.4,3.935FlusilazoleY=3923.0X-3302.70.9966100,96.2,92.316.9,4.3,9.536Flumiclorac-pentylY=4535.25X-5207.40.996098.7,93.1,86.810.8,5.3,9.137MolinateY=17776X-275760.9983101,94.7,86.08.3,5.2,2.438CyproconazoleY=6152.18X-866460.9991113,73.3,76.93.6,1.8,8.739FenhexamidY=48621.8X+435430.993598.0,97.4,75.24.6,12.3,4.140TolylfluanidY=27758X+384920.998681.0,90.2,85.64.6,1.8,6.841AlachlorY=1738.3X-4100.20.9991105,99.2,89.612.4,11.7,17.142MethiocarbY=413.13X-463.160.996575.3,84.6,80.114.9,8.7,11.243CarbarylY=12642X-278150.990462.8,86.1,85.010.4,3.3,5.844MethoxyfenoxideY=4842.5X+32490.991667.3,70.0,80.914.4,6.4,9.545MyclobutanilY=831.19X-2818.40.991770.2,100,94.110.1,4.5,5.146PirimicarbY=12000X+2791.80.996078.7,90.2,88.93.4,2.8,8.247CarbofuranY=1358.5X+309000.995277.5,91.4,86.517.1,4.1,8.248LinuronY=676.26X-9107.10.995592.5,78.4,74.42.8,6.4,6.249BitertanolY=41333X+569860.990076.2,95.7,91.04.6,3.1,8.350SpiromesifenY=44467X-934800.997190.0,90.1,80.96.1,1.8,6.151ChlortoluronY=1419.9X-914.310.9960104,102,94.49.0,7.1,10.452Halosulfuron-methylY=26971X-264470.995387.0,106,89.24.2,2.0,4.953ChlorantraniliproleY=22124X-4601.10.999796.8,89.9,87.17.6,2.8,8.454ChlorsulfuronY=14783.8X+154140.997796.7,88.3,81.515.1,6.0,6.855Chlorimuron-ethylY=12069X+164250.997087.5,91.7,84.46.2,6.7,9.056ProchlorazY=4761.5X-239970.995194.2,93.4,85.47.4,7.1,5.057ImazethapyrY=13824X-5268.70.997072.8,62.9,67.25.2,13.7,7.658AzoxystrobinY=24436X-128960.994078.9,83.0,75.04.9,3.7,8.059PyrimethanilY=11334X+5292.20.996690.0,91.9,86.88.9,4.7,9.260MethomylY=1697.1X-266080.9988113.7,63.0,67.52.1,2.0,6.2
(续表2)
No.CompoundRegressionequationrRecovery(%)RSD(%)61EthoprophosY=8.2786X-202.230.993571.7,92.7,82.719.2,12.9,18.462CyromazineY=25706X-483280.997375.3,99.6,76.44.6,2.3,4.263NaptalamY=1263.2X-6084.80.994796.0,84.1,73.46.2,13.7,7.364PrometrynY=5582.3X-350.780.998890.5,87.2,83.59.0,2.4,8.565TriforineY=10558X+106060.998575.7,91.0,84.06.8,7.6,8.366MetribuzinY=29567X+89950.993980.0,108,95.913.6,4.7,9.367MetaflumizoneY=2381.4X-6520.60.994865.2,84.2,69.86.8,2.4,11.668Clodinafop-propargylY=2833.6X-2935.20.993899.8,103,98.017.3,10.1,6.169ClothianidinY=49046X-386810.993897.7,112,89.09.7,2.3,4.370ThiaclopridY=8258.6X+4253.90.997175.7,87.7,82.13.0,3.7,5.971ThiamethoxamY=10066X+123780.994983.2,88.5,82.14.4,3.9,7.272ThiabendazoleY=31163X+722530.992485.3,108,90.99.5,5.6,8.373BuprofezinY=23310X+2.05180.991180.8,79.2,74.56.0,5.6,4.674TrifloxysulfuronY=20284X-456740.997487.7,92.2,83.25.9,2.7,4.975TricyclazoleY=6089X+6668.70.998096.7,84.8,80.16.5,2.6,7.676TralkoxydimY=7129.2X-209900.9940113,71.1,66.710.6,3.7,6.977TriadimenolY=1205.6X-3032.80.998888.8,90.2,81.95.2,1.5,6.578TriadimefonY=5525.8X-117480.998585.5,89.6,83.03.1,3.4,7.979OxamylY=17572X-369670.998785.5,88.4,83.65.7,2.3,8.680DiclosulamY=1050.2X-525.130.990887.2,94.0,87.15.5,5.8,10.581MandipropamidY=8769.9X+4782.60.9951119,71.7,71.84.3,15.3,14.282PropamocarbY=12202X-853.910.996896.7,92.1,80.14.3,15.3,14.283CymoxanilY=1083.2X-7579.20.9964122,67.4,67.114.6,17.7,4.384TetraconazoleY=337.73X-435.750.9931115,81.4,78.64.7,3.4,7.485AldicarbY=16190X-141340.9966105,91.8,86.210.4,3.0,8.686DesmediphamY=1859.8X-702.550.9934119,80.2,69.93.0,12.2,5.187CarboxinY=11129X-4348.20.9920101,95.7,91.610.2,5.1,10.088TrifloxystrobinY=32750X+583150.998470.0,110,79.16.3,3.2,3.489TebuconazoleY=44525X+343830.994087.8,101,84.76.7,3.9,4.390SethoxydimY=5352.3X+52.0460.993488.3,92.1,89.712.9,4.0,10.091DimethomorphY=13394X-187080.996371.2,86.3,81.416.1,19.4,13.492DiniconazoleY=45743X+869540.992785.8,88.7,71.59.8,3.2,7.593MesotrioneY=9243.4X-115560.996797.0,98.6,93.911.6,4.9,7.594PhoximY=4680.3X-5977.90.994185.5,90.2,88.97.4,2.8,8.295NicosulfuronY=4320.1X-467690.994695.8,99.9,94.12.8,2.9,8.596OmethoateY=18471X+593850.9929101,86.2,76.36.1,4.0,7.697DifenzoquatY=2800.2X-5955.70.994079.7,89.0,84.03.5,1.9,6.998MetconazoleY=2955.9X-4027.90.997894.0,91.2,86.34.9,5.6,6.399IsoprocarbY=27805X-392660.999497.0,90.7,85.313.3,4.3,9.2100ClomazoneY=4491.7X-23230.9964108,78.6,73.52.1,13.1,8.1101ImazalilY=54382X-389000.997788.2,92.6,84.54.4,3.0,6.7102IndoxacarbY=15843X+1.29560.999194.7,88.9,86.414.4,5.2,9.6103AmetrynY=3491.6X-125880.9958108,99.3,90.56.1,5.2,6.8104AtrazineY=213.48X+886.890.992172.8,88.7,83.45.2,2.4,5.3105Piperonyl-butoxideY=3900.6X-454590.9953109,88.6,85.513.5,4.7,7.0106IpconazoleY=11579X-505070.998888.7,95.1,97.76.0,2.7,13.5107Fenobucarb(bpmc)Y=7073.1X-2470.60.9972119,96.2,92.217.7,6.4,9.1108ImazosulfuronY=5014.4X-416390.9971110,72.1,69.73.5,3.9,6.1109Carfentrazone-ethylY=5856.3X+235130.997897.7,92.8,86.013.2,10.2,7.3110FenpyroximateY=18329X-929950.990296.2,85.9,78.66.4,3.6,8.0111FlumetsulamY=6344.76X-179850.9997105,96.1,92.110.3,7.3,11.1112Flufenpyr-ethylY=4017.78X-6134.20.990076.5,90.0,80.74.0,6.5,7.4113FlufenoxuronY=5735.9X+6272.90.998889.2,92.3,86.45.2,4.4,8.1114SpirotetramatY=44.829X+61.9580.9991101,82.9,88.39.7,1.8,1.7115DiflubenzuronY=16338X-315140.996598.3,100,95.217.3,9.9,2.5116TeflubenzuronY=50.172X-116.830.9987108,92.3,86.515.9,6.6,7.3117FlubendiamideY=1250.4X-3276.60.9982100,92.3,83.712.6,8.2,4.5118FomesafenY=44.829X+61.9580.9991108,99.2,89.811.6,6.6,5.7119ChlorbenzuronY=10773X-249.920.997370.0,90.7,80.218.6,14.9,17.0120FlonicamidY=2051.82X-4207.90.995173.5,109,88.511.9,7.2,6.4121AcifluorfenY=1399.9X-5123.50.999278.9,83.0,75.04.9,3.7,8.0
表3 4种果蔬样品两种检测方法比对结果Table 3 Test results of 4 vegetable samples by two methods
2.5.3 方法比对 应用所建立的分析方法和GB/T 20769-2008方法分别对白菜、豆角、黄瓜、柑桔4个基质样品进行了122种目标农药残留检测,分别检出克百威、噻虫胺、异丙威和氧乐果,结果表明两种方法的检测结果相近(见表3)。
本文采用1%乙酸-乙腈溶液提取122种目标化合物,经改进的QuEChERS方法提取净化后,建立了针对香港《规例》中122种农药的LC-MS/MS定量测定及确证方法。该法操作简便,耗时短,溶剂用量少,灵敏度高,稳定性好;具有较高的回收率、良好的精密度和较低的定量下限,适用于日常供港食品中农残检测工作,可显著降低检测成本,具有良好的实际应用价值。
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Determination of 122 Pesticide Residues in Fruits and Vegetables from Regulation of Pesticides in Hong Kong by QuEChERS Combined with Ultra Performance Liquid Chromatography-Tandem Mass Spectrometry
ZHANG Jian-ying*,DENG Hui-fen,LI Yue-mei,LIN Shan,YUE Zhen-feng,WU Wei-dong
(Food Inspection & Quarantine Center,Shenzhen Entry-Exit Inspection and Quarantine Bureau,Shenzhen 518045,China)
A method for the determination of 122 pesticide residues in fruits and vegetables from the Hong Kong's regulation was developed by QuEChERS combined with ultra performance liquid chromatography-tandem mass spectrometry(UPLC-MS/MS).The quantification and confirmation was achieved by electrospray ionization(ESI) in positive and negative ion mode using multiple reaction monitoring(MRM) mode,and the analytes were quantified by the external standard method.The standard curves of 122 target compounds were linear in the range of 0.010-0.20 mg/L,with correlation coefficients(r) not less than 0.99.The limits of quantitation(LOQ) were 0.010 mg/kg.The recoveries at three spiked levels were in the range of 60%-110% with RSDs of 1.8% and 19.4%.The method had the advantages of rapidness,simplicity,time-saving,high sensitivity and good stability,and could significantly reduce the test cost.
QuEChERS;ultra performance liquid chromatography-tandem mass spectrometry(UPLC-MS/MS);pesticide residues
2017-01-18;
2017-03-15
国家质检总局项目(2016IK240)
10.3969/j.issn.1004-4957.2017.07.002
O657.3;TQ460.72
A
1004-4957(2017)07-0849-09
*通讯作者:张建莹,高级工程师,研究方向:食品中农兽药残留分析,Tel:0755-26881671,E-mail:zhangjianying1001@163.com