摘要
采用反反相色谱-串联质谱法建立了直接测定植物源性食品中草甘膦(GLY)及其主要代谢物氨甲基膦酸(AMPA)的方法。样品用水提取,阴离子交换柱(MAX)净化,以5 mmol/L的乙酸铵溶液和5%水-95%乙腈的乙酸铵溶液为流动相,反反相色谱分离,采用电喷雾离子源、负离子扫描模式和多反应监测模式质谱检测,外标法定量。草甘膦和氨甲基膦酸的线性范围分别为10～500μg/L和20～1 000μg/L,相关系数(r2)均大于0.99。方法的检出限(S/N=3)均为0.01 mg/kg,定量下限(S/N=10)分别为0.02 mg/kg和0.04 mg/kg。在6种基质中,GLY和AMPA在3个加标水平下的回收率为78%～113%,相对标准偏差(RSD,n=6)为3.2%～11.0%。方法的灵敏度和回收率高,选择性好,能满足日常食品检测工作的要求。
A high performance aqueous normal phase （ANP） chromatography -tandem mass spectro- metric method was established for the simultaneous determination of glyphosate（GLY） and aminom- ethylphosphonic acid （AMPA） in plant-derived foodstuff. The sample was extracted with ultrapure grade water, and purified with anion-exchange column （MAX）. The seperation of GLY and AMPA were carried out by ANP chromatography using 5 mmolfL ammonium acetate （A） and 5% water - 95% acetonitrile ammonium acetate solution （B） as mobile phases. The detection of target com- pounds was performed by MS under electrospray ionization source, negative scanning mode and multi- ple reaction monitoring. The external standard method was used for the quantitative analysis. The re- sult indicated that the linear ranges of GLY and AMPA were in the concentration ranges of 10 -500 I^g/L and 20 - 1 000 i^g/L, respectively, with correlation coefficients more than 0. 99. The limits of detection（ LODs, SIN = 3） of two compounds were both 0. 01 mg/kg, and the limits of quantita- tion （ LOQs, SIN = 10） were 0. 02 mg/kg for GLY and 0. 04 mg/kg for AMPA, respetively. The re- coveries of GLY and AMPA in six matries ranged from 78% to 113% , with relative standard devia- tions （RSDs） of 3.2 - 11.0%. The method could meet the requirements for daily food determination with its high sensitivity, recovery and selectivity.
出处
《分析测试学报》
CAS
CSCD
北大核心
2013年第2期199-204,共6页
Journal of Instrumental Analysis
基金
国家质检总局科研项目资助(2011IK214)
关键词
草甘膦
氨甲基膦酸
反反相色谱
液相色谱-串联质谱法
阴离子交换柱
glyphosate
aminomethylphosphonic acid
aqueous normal phase
liquid chromatogra- phy- tandem mass spectrometry
anion-exchange column
