摘要
建立了气相色谱-负化学源质谱法（GC-NCI MS）测定水中2-甲-4-氯（MCPA）和2，4-滴（2，4-D）2种酸性除草剂的分析方法。水样经过Oasis HLB柱萃取后，进行五氟苄基溴（PFBBr）衍生化，用2，4-二氯苯乙酸（2，4-DCPA）作内标进行定量分析，并以2-甲4-氯丙酸（mecoprop）作回收率指示物对整个分析过程进行监控，以保证分析结果的准确性。mecoprop、MCPA和2，4-D在5、100、200ng／L3个不同添加水平下的回收率在82％～135％范围内，RSD在1．3％～9．3％范围内，在1～200μg/L线性范围内，相关系数r大于0．997，MCPA、2，4-D的方法检出限分别为0．60、0．45ng／L。2007年11月采用GC-NCI MS方法对南方地区某河流中的MCPA和2，4-D含量进行调查，其质量浓度分别不大于19．4ng／L和6．2ng／L，监测结果表明，该河流水质没有受到MCPA和2，4-D酸性除草剂的污染。
An analytical method for the determination of MCPA （ （4-chloro-2-methylphenoxy）-acetic acid） and 2, 4-D（ （2, 4-dichlorophenoxy）-acetic acid） in water was developed based on gas chromatography with negative chemical ionization mass spectrometry（GC -NCI MS）. The water sample, after being extracted with Oasis HLB and derivatized with PFBBr, was determined with 2, 4-DCPA （（2, 4-dichlorophenyl）-acetic acid） as internal standard. The accuracy of the measurements of analytes was ensured with recovery correction strategy employing mecoprop （2-（ 4-chloro-2-methylphenoxy） propanoic acid） as surrogate. The recovery studies were performed at 5, 100 and 200 ng/L fortification levels for mecoprop, MCPA and 2, 4-D, respectively, and the recoveries ranged from 82% to 135% with a relative standard deviation between 1.3% and 9. 3% . The developed method was linear over the range of 1 - 200μg/L with correlation coefficients more than 0. 997. The detection limit of the method for MCPA and 2, 4-D was 0. 60 and 0.45 ng/L, respectively. The method was applied in the determination of MCPA and 2, 4-D in water samples from some river of south of China in November 2007 with the concentrations less than 19.4 and 6.2 ng/L, respectively. The results showed that the pollution state of MCPA and 2, 4-D in the area was not serious.
出处
《分析测试学报》
CAS
CSCD
北大核心
2008年第8期816-819,824,共5页
Journal of Instrumental Analysis
基金
国家自然科学基金资助项目(NSFC40688001,40771180)
