刘洪波
气质联用测定杭白菊等3种中药中5种拟除虫菊酯类农药残留
刘洪波
(浙江农林大学 林业与生物技术学院,浙江 临安311300)
采用浊点萃取反萃取样品前处理方法,建立气质联用测定杭白菊Chrysanthemum morifolium,白术Atractylodes macrocephala和山茱萸Cornus officinalis中甲氰菊酯、高效氯氟氰菊酯、氯菊酯、氯氰菊酯和氰戊菊酯等5种拟除虫菊酯类农药残留量的测定方法。选用聚乙二醇6000作为浊点萃取的提取剂,异辛烷为反萃取剂,HP-5MS色谱柱为分析柱,气相色谱质谱法进行检测,外标法计算含量。结果表明:5种拟除虫菊酯类农药在15.00~2 000.00 μg·kg-1范围内呈良好的线性关系,相关系数为0.955~0.999,检出限为0.63~3.10 μg·kg-1,定量限为2.10~10.31 μg·kg-1。3种中药的加标回收率为71.22%~91.00%,相对标准偏差(RSD)为3.20%~8.20%。该方法操作简单、安全,可应用于杭白菊、白术、山茱萸中5种拟除虫菊酯类农药残留的检测。图4表4参19
杭白菊;白术;山茱萸;拟除虫菊酯类农药;气相色谱-质谱联用仪;残留检测
甲氰菊酯、高效氯氟氰菊酯、氯菊酯、氯氰菊酯和氰戊菊酯等是一类拟除虫菊酯类杀虫剂,用于防治鳞翅目Lepidoptera和鞘翅目Coleoptera等多种农林业害虫和卫生害虫[1-2]。对拟除虫菊酯类农药的检测一般采用气相色谱法(ECD,FID),有时也用高效液相色谱法,较少用气相色谱-质谱联用仪(GC-MS)进行检测[3-5]。现阶段中药中农药最大残留量没有统一的标准,在此先参照GB2763-2012《食品中农药最大残留限量标准》中的有关数据。标准中规定了蔬菜、水果、茶叶等食品中这5种农药的最大残留量,甲氰菊酯的最大残留范围为0.10~5.00 mg·kg-1,高效氯氟氰菊酯为0.02~15.00 mg·kg-1,氯菊酯为0.10~ 20.00 mg·kg-1,氯氰菊酯为0.05~20.00 mg·kg-1,氰戊菊酯为0.02~3.00 mg·kg-1[6]。本研究采用浊点萃取-反萃取技术,选择合适的色谱柱在GC-MS上对这5种农药进行检测,以期建立杭白菊Chrysanthemum morifolium,白术Atractylodes macrocephala,山茱萸Cornus officinalis等3种中药中这5种农药残留的检测方法。
1.1 材料、仪器与试剂
供试材料杭白菊(花类药材)、浙白术(根茎类药材)、山茱萸(果实类药材)均采自浙江农林大学中药栽植基地。
5975C-7890A气相色谱-质谱联用仪(美国Agilent公司),HH-4数显恒温水浴锅(中国国华电器有限公司),KQ-300E超声波清洗器(中国昆山超声仪器有限公司),CF16RXⅡ高速冷冻离心机(中国日本日立公司),FRESCO17高速冷冻离心机(德国Thermo公司)。
甲氰菊酯(99.4%,迪马公司);高效氯氟氰菊酯(99%,阿拉丁公司);氯菊酯(99.5%,迪马公司);氯氰菊酯(99.0%,阿拉丁公司);氰戊菊酯(99.0%,迪马公司);乙腈(色谱纯,天津四友);聚乙二醇6000(化学纯,国药集团化学试剂有限公司);异辛烷(色谱纯,阿拉丁公司);硫酸铵(化学纯,湖州湖试化学试剂有限公司);超纯水。
1.2 仪器条件
色谱条件:HP-5MS毛细管柱[30.00 m×250.00 μm×0.25 μm,(5%-苯基)-甲基聚硅氧烷,非极性柱];DB-5MS毛细管柱(30.00 m×250.00 μm×0.25 μm,苯基亚芳基聚合物,非极性柱);DB-1701毛细管柱[30.00 m×250.00 μm×0.25 μm,(14%-氰丙基苯基)-二甲基聚硅氧烷,弱/中极性柱];HPINNOWAX毛细管柱(30.00 m×250.00 μm×0.25 μm,聚乙二醇,强极性柱);不分流、单锥型、无玻璃纤维型衬管;载气为高纯氦气(>99.999%);进样口温度250℃;柱升温程序:起始温度90℃,恒温1.0 min后以30℃·min-1升温至230℃,恒温1.0 min后以2℃·min-1升温至280℃;进样方式:不分流;进样量1.00 μL。
质谱条件:连接处温度为280℃;EI离子源,电子能量为70 eV,离子源温度为230℃;扫描方式:全扫描,选择离子检测;溶剂延迟5.5 min;谱库NIST08。
1.3 实验方法
色谱柱优化及5种菊酯类农药的检出限、定量限等测定方法:把甲氰菊酯、高效氯氟氰菊酯、氯菊酯、氯氰菊酯、氰戊菊酯等用乙腈溶解,混合液稀释到10.00~4 000.00 μg·kg-1,取4 000.00 μg·kg-1溶液进行全扫描检测,然后在4种类型的毛细管柱中选取分离度好的,选择3种质量分数(10.00~ 15.00,500.00,2 000.00 μg·kg-1)进行选择离子监测扫描(条件见表1),确定这5种菊酯类农药的检出限(S/N=3),定量限(S/N=10),线性关系和线性范围,重复5次。
表1 5种拟除虫菊酯类农药的质谱条件(HP-5MS)Table 1 MS conditions of 5 pyrethroid pesticides(HP-5MS)
浊点萃取-反萃取实验步骤(优化后):称取1.0 g已粉碎的中药干样于20.0 mL刻度试管中,加入1.5 g硫酸铵和5.0 mL体积分数为8%乙腈水溶液,充分混匀后置于超声波清洗器中超声1 h,过滤后用2.0 mL体积分数为8%乙腈水溶液冲洗残渣,冲洗3次,合并滤液并置于离心管中,依次加入0.9 mL质量浓度为20%聚乙二醇6000水溶液和4.5 g硫酸铵,用体积分数为8%乙腈水溶液定容至15.0 mL,使聚乙二醇6000最终质量浓度分别为12.0 g·L-1,乙腈最终体积分数为8%,硫酸铵的最终质量浓度为40%,然后置于30℃水浴中保持30.0 min,最后以3 500 r·min-1离心10 min,用长细针头的注射器吸出下部水相后留下表面活性剂富集相(<0.5 mL)。用超纯水把表面活性剂富集相稀释至0.5 mL,加入0.2 mL异辛烷,超声25.0 min后,取上层异辛烷相1.0 μL进气相色谱-质谱联用仪检测。
2.1 色谱柱优化结果
按照1.3节中的实验方法,取4 000.00 μg·kg-1混合溶液在HP-5MS,DB-5MS,DB-1701,HP-INNOWAX等4种毛细管柱上进行全扫描检测,得到的总离子流图见图1~4。由图1~4可知:5种拟除虫菊酯类农药在HP-5MS,DB-5MS毛细管柱上分离度较好,在HP-5MS柱上要优于DB-5MS柱上。HP-5MS是一款非极性通用柱,DB-5MS也是一款非极性柱,根据检测物的特性,和检测结果相符,但因HP-5MS柱效果优于DB-5MS柱,故选择在HP-5MS柱上进行选择离子检测。
图1 HP-5MS全扫描总离子流图Figure 1 Totalion chromatogram of5 pyrethroid pesticides with HP-5MS by full scan
图2 DB-5MS全扫描总离子流图Figure 2 Totalion chromatogram of5 pyrethroid pesticides with DB-5MS by full scan
图3 DB-1701全扫描总离子流图Figure 3 Total ion chromatogram of 5 pyrethroid pesticides with DBv1701 by full scan
图4 HP-INNOWAX全扫描总离子流图Figure 4 Totalion chromatogram of5 pyrethroid pesticides with HP-INNOWAX by full scan
2.2 5种拟除虫菊酯类农药的检出限、定量限、线性关系和线性范围
取不同质量分数(10.00~15.00,500.00,2 000.00 μg·kg-1)的5种拟除虫菊酯类农药标准溶液按照1.2~1.3节中的检测条件进样,确定它们的最低检出限(S/N=3),定量限(S/N=10),回归方程和相关系数,具体见表2。其中氯菊酯中的同分异构体含量氯菊酯Ⅰ∶氯菊酯Ⅱ为1.00∶2.89;氯氰菊酯中的同分异构体含量氯氰菊酯Ⅰ∶氯氰菊酯Ⅱ∶氯氰菊酯Ⅲ∶氯氰菊酯Ⅳ为1.46∶2.32∶1.00∶1.42;氰戊菊酯中的同分异构体含量氰戊菊酯Ⅰ∶氰戊菊酯Ⅱ为2.36∶1.00。从表2可以看出:本研究中5种农药的最低检出限为0.63~3.10 μg·kg-1,定量限为2.10~10.31 μg·kg-1,线性范围为15.00~2 000.00 μg·kg-1,相关系数R 为0.955~0.999,各项指标完全能够满足5种拟除虫菊酯类农药残留分析检测的要求,该方法是可行的。
表2 回归方程、相关系数、最低检出限和定量限Table 2 Regression equation,correlation coefficient,limit of detection and limit of quantitation
2.3 回收率与精密度
在1.0 g的中药干样中分别添加3种浓度50.00,100.00,500.00 μg·kg-1的混合标准溶液1.0 mL,充分混匀,按照1.3节中的实验方法测定农药回收率,同一个样重复测定5次(n=5),结果见表3。从表3可以看出:杭白菊中5种拟除虫菊酯类农药的平均回收率(第1列)为75.02%~91.00%,相对标准偏差(RSD)(第1列)为3.2%~8.2%;白术中5种拟除虫菊酯类农药的平均回收率(第2列)为71.22%~ 86.23%,RSD(第2列)为3.5%~8.1%;山茱萸中5种拟除虫菊酯类农药的平均回收率(第3列)为72.03% ~89.22%,RSD(第3列)为3.2%~8.0%。
表3 加标农药回收率(n=5)Table 3 Recoveries at spiked concentrations of 50.00-500.00 μg·kg-1
2.4 样品分析
按以上的方法测定了市售的杭白菊、白术、山茱萸等样品中的菊酯类农药残留,样品中的菊酯类农药质谱图通过和标准品质谱图比对,匹配度较高。杭白菊中检出含有甲氰菊酯11.05 μg·kg-1,白术中检出含有氯菊酯Ⅰ和氯菊酯Ⅱ,分别为3.57 μg·kg-1和10.31 μg·kg-1,山茱萸中未检出。
表4 不同样品中农药残留量Table 4 Pyrethroid pesticides residues in different samples
本研究建立了浊点萃取反萃取-气质联用测定杭白菊、白术和山茱萸中甲氰菊酯、高效氯氟氰菊酯、氯菊酯、氯氰菊酯和氰戊菊酯等5种拟除虫菊酯类农药残留量的测定方法。该方法操作简单安全,能够满足这3种中药中5种拟除虫菊酯类农药残留的实际检测。
[1] 张敏恒.农药品种手册精编[M].北京:化学工业出版社,2013.
[2] 成卓敏.简明农药使用手册[M].北京:化学工业出版社,2009.
[3] 杨蕾,王保兴,侯英,等.SBSE-TDS-GC-MS快速测定茶叶中拟除虫菊酯类农药残留[J].食品科学,2007,28 (11):435-439. YANG Lei,WANG Baoxing,HOU Ying,et al.Rapid determination of pyrethroid pesticide residues in tea by stir bar sorptive extraction-thermal desorption-gas chromatography-mass spectrometry[J].Food Sci,2007,28(11):435-439.
[4] 莫小荣,郑春慧,陈建伟,等.浊点萃取-异辛烷反萃取-气相色谱测定茶叶中拟除虫菊酯农药残留[J].分析化学,2009,37(8):1178-1182. MO Xiaorong,ZHENG Chunhui,CHEN Jianwei,et al.Cloud point extraction coupled with ultrasonic-assisted backextraction for determination of pyrethroid pesticides in tea by gas chromatography with electron capture detection[J]. Chin J Anal Chem,2009,37(8):1178-1182.
[5] 张舒婷,陈晓辉,于治国,等.浊点萃取-气相色谱法测定槲寄生中 20种农药残留[J].中国中药杂志,2009,34(20):2577-2580. ZHANG Shuting,CHEN Xiaohui,YU Zhiguo,et al.Determination of twenty pesticide residues in Viscum coloratumby gas chromatography using cloud-point extraction[J].China J Chin Mat Med,2009,34(20):2577-2580.
[6] 农业部农药检定所,国家农药残留标准审评委员会秘书处.GB2763-2012食品中农药最大残留限量标准应用指南[M].北京:中国农业出版社,2013.
[7] LEMOS V A,SANTOS M S,DAVID G T,et al.Development of a cloud-point extraction method for copper and nickel determination in food samples[J].J Hazard Mater,2008,159(2):245-251.
[8] POURREZA N,ZAREIAN M.Determination of orange II in food samples after cloud point extraction using mixed micelles[J].J Hazard Mater,2009,165(1):1124-1127.
[9] SILVA E L,ROLDAN P S.Simultaneous flow injection preconcentration of lead and cadmium using cloud point extraction and determination by atomic absorption spectrometry[J].J Hazard Mater,2009,161(1):142-147.
[10] PALEOLOGOS E K,GIOKAS D L,KARAYANNIS M I.Micelle-mediated separation and cloud-pointextraction [J].Trends Anal Chem,2005,24(5):426-436.
[11] LIU wei,ZHAO Weijun,CHEN Jianbo,et al.A cloud point extraction approach using Triton X-100 for the separation and preconcentration of Sudan dyes in chilli powder[J].Anal Chim Acta,2007,605(1):41-45.
[12] 吴胜芳,王利平,刘杨岷,等.加速溶剂萃取-气相色谱串联质谱测定菊花中的3种菊酯类农药残留量[J].分析试验室,2008,27(11):65-67. WU Shengfang,WANG Liping,LIU Yangmin,et al.Determination of three pyrethroids in chrysanthemum by accelerated solvent extraction-gas chromatography Ptandem mass spectrometry[J].Chin J Anal Labor,2008,27(11):65 -67.
[13] 薛平,杜利君,林勤保,等.气相色谱-质谱法测定乳制品中17种拟除虫菊酯农药残留方法的研究[J].分析测试学报,2010,29(9):948-952. XUE Ping,DU Lijun,LIN Qinbao,et al.Determination of 17 pyrethroid pesticides residues in dairy by gas chromatography-mass spectrometry[J].J Instrum Anal,2010,29(9):948-952.
[14] 崔淑华,郭庆龙,张峰,等.气相色谱质谱法测定花生及制品中 17种菊酯类农药残留[J].分析化学,2013,41(6):944-948. CUI Shuhua,GUO Qinglong,ZHANG Feng,et al.Determination of 17 pyrethroid pesticides residues in peanut and its products by matrix solid-phase dispersion-gel permeation chromatography coupled with gas chromatography-negative chemical ionization mass spectrometry[J].Chin J Anal Chem,2013,41(6):944-948.
[15] 苏建峰,陈晶,陈竞秀,等.混合食品中19种菊酯类农药残留的极性区间排列净化-气相色谱-质谱法测定[J].分析测试学报,2010,29(7):686-690. SU Jianfeng,CHEN Jing,CHEN Jingxiu,et al.Determination of 19 pyrethroid pesticides residues in mixed foods by GC-MS with polar-interva-larrangement pur ification[J].J Instrum Anal,2010,29(7):686-690.
[16] 陈建波,王云飞,奚道珍.浊点萃取技术及其在农药残留分析中的应用[J].农药,2011,50(7):479-486. CHEN Jianbo,WANG Yunfei,XI Daozhen.Review of cloud point extraction technology and its application in pesticide residue analysis[J].Agrochemicals,2011,50(7):479-486.
[17] FONTANA A R,SILVA M F,MARTNEZ L D,et al.Determination of polybrominated diphenyl ethers in water and soil samples by cloud point extraction-ultrasound-assisted back-extract ion-gas chromatography-mass spectrometry[J].J Chromatogr A,2009,1216(20):4339-4346.
[18] PANG Guofang,CAO Yanzhong,ZHANG Jinjie,et al.Validation study on 660 pesticide residues in animal tissues by gel perm eation chromatography cleanup/gas chromatography-mass spectrometry and liquid chrom atography-tandem mass spectrometry[J].J Chromatogr A,2006,1125(1):1-30.
[19] 吴卫东,林黎,蓝芳,等.气相色谱-质谱法检测食品中甲氰菊酯的残留量[J].江西农业学报,2012,24 (8):73-76. WU Weidong,LIN Li,LAN Fang,et al.Determination of fenpropathrin residue in food by using gas chromatographymass spectrometry method[J].Acta Agric Jiangxi,2012,24(8):73-76.
Five pyrethroid pesticide residues for three kinds of traditional Chinese medicines using GC-MS
LIU Hongbo
(School of Forestry and Biotechnology,Zhejiang A&F University,Lin’an 311300,Zhejiang,China)
Methods for residual determination by gas chromatography mass spectrometry (GC-MS)of five pyrethroid pesticides in Chrysanthemum morifolium,Atractylodes macrocephala and Cornus officinalis were established.Cloud point extraction-back extraction was used as sample pretreatment method,and PEG 6000 was used as an extraction agent,isooctane was used as a back-extractant,a chromatographic column HP-5MS was used as an analytical column.Content was calculated by the external standard method using GC-MS.Results showed a linear range from 15.00 to 2 000.00 μg kg-1with favorable correlation coefficients (r=0.955-0.999). For the five pyrethroid pesticides,the limit of detection was 0.63-3.10 μg·kg-1and quantitation was 2.10-10.31 μg·kg-1.At spiked concentrations of 50.00-500.00 μg·kg-1,recoveries ranged from 71.22%to 91.00%. This proposed method can be applied to determine pyrethroid pesticide residues in Chrysanthemum morifolium, A.macrocephala,and Cornus officinalis.[Ch,4 fig.4 tab.19 ref.]
Chrysanthemum morifolium;Atractylodes macrocephala;Cornus officinalis;pyrethoid pesticide; GC-MS;residue detection
S567;TS207.5+3
A
2095-0756(2015)01-0110-06
浙 江 农 林 大 学 学 报,2015,32(1):110-115
Journal of Zhejiang A&F University
10.11833/j.issn.2095-0756.2015.01.016
2014-04-09;
2014-09-04
浙江省科技厅公益性技术应用研究(分析测试)项目(2013C37099)
刘洪波,实验师,从事生物农药、林木病虫害防治等研究。E-mail:lhb@zafu.edu.cn