固相萃取-超高效液相色谱-串联质谱法测定沉积物中二甲四氯残留  

Determination of 4-chloro-2-methylphenoxyacetic acid residues in sediment using solid phase extraction and ultra-performance liquid chromatography-tandem mass spectrometry

作　　者：吴东明[1,2] 吴小燕 陈恩华 武春媛 李勤奋[1,2] WU Dongming;WU Xiaoyan;CHEN Enhua;WU Chunyuan;LI Qinfen(Institute of Environment and Plant Protection,Chinese Academy of Tropical Agricultural Sciences,Haikou 571101,China;National Agricultural Experimental Station for Agricultural Environment,Danzhou 571737,Hainan Province,China)

机构地区：[1]中国热带农业科学院环境与植物保护研究所,海口571101 [2]国家农业环境儋州观测实验站,海南儋州571737

出　　处：《农药学学报》2020年第6期1040-1046,共7页Chinese Journal of Pesticide Science

基　　金：国家自然科学基金(42007135,41371465);公益性行业(农业)科研专项(有机化学品污染农田和农产品质量安全综合防治技术方案)子课题(201503107-14);海南省重大科技计划(ZDKJ2017002);中国热带农业科学院基本科研业务费专项资金(1630042020008,1630042020010)。

摘　　要：针对沉积物性质特殊以及二甲四氯(MCPA)在其中环境风险大等问题,建立了超高效液相色谱-串联三重四极杆质谱(UPLC-MS/MS)快速测定沉积物中MCPA残留的方法。样品先经酸化的乙腈溶液超声萃取后,以石墨化碳黑-氨基串联固相萃取柱净化,再以硅烷醇基部分裸露的HSS T3柱为分离柱,采用乙腈-水溶液为洗脱液进行梯度洗脱,将MCPA与杂质分离,后经电喷雾离子源负离子扫描(ESI-)、多反应监测模式(MRM),基质匹配标准溶液外标法定量。结果表明:在1~100μg/L范围内,MCPA的质量浓度与对应的色谱峰面积间呈良好的线性关系,R2=0.999 7,定量限为0.1μg/kg。在0.1~5μg/kg添加水平下,MCPA在沉积物中的回收率在80%~108%之间,相对标准偏差在3.6%~8.2%之间。该方法通过增强色谱柱对MCPA的吸附作用,均衡了UPLC-MS/MS法建立过程中MCPA的"色谱柱保留"同"质谱离子化"互相矛盾的问题,具有分析时间短、准确度好和灵敏度高等优点,适用于沉积物中MCPA残留的痕量分析。4-chloro-2-methylphenoxyacetic acid(MCPA) is one of the high toxic herbicide that may cause the potential environmental risks for sediment. Thus, a simple and sensitive ultra-performance liquid chromatography-tandem mass spectrometry(UPLC-MS/MS) was developed for determination of MCPA in sediment samples. The best conditions for analysis were as follow: sediment sample was treated by ultrasonic extraction with the acidified acetonitrile solution;the extract was then cleaned up with GCB-NH2 solid phase extraction column;furthermore, the mobile phase consisting of acetonitrile and ultrapure water was used under gradient elution to isolate MCPA from impurities with HSS T3 column as the separator. The mass spectrometric detection was conducted in negative electrospray ionization with multiple reaction monitoring mode. The quantification of MCPA was performed using the matrix matched/external standard method. With the established method, an excellent linear relationship between chromatographic peak area and mass concentration of MCPA was obtained in the range of 1-100 μg/L(R2 = 0.999 7), and the quantitation limit(LOQ) sensitively reached 0.1 μg/kg.Under the fortified level of 0.1-5 μg/kg MCPA, the satisfactory relative recoveries(80%-108%) of MCPA in sediment were achieved with relative standard deviations of 3.6%-8.2%. During the establishment of UPLC-MS method, the contradiction between ’column retention’ and ’mass spectrometry ionization’ of MCPA was worked out by strengthening the binding forces between MCPA and chromatographic column. This method is rapid, accurate and sensitive, and is suitable for the analysis of trace MCPA residues in sediment.

关 键 词：固相萃取 超高效液相色谱-串联质谱 超声萃取 沉积物 二甲四氯 残留 

分 类 号：S482.4[农业科学—农药学] T450.263[农业科学—植物保护]