摘要
建立了一种分散固相萃取结合高效液相色谱-串联质谱法测定茶叶样品中草甘膦(PMG)及其代谢物氨甲基膦酸(AMPA)残留量的分析方法.样品经0.2%甲酸水超声提取,层状氢氧化镁铝水滑石(Mg-Al-LDHs)吸附富集,碳酸钠溶液洗脱后,以9-芴基氯甲酸酯(FMOC-Cl)为衍生剂衍生2h,Kinetex C18柱(50mm×2.1 mm,2.6 μm,Phenomenex)分离,以乙腈-5 mmol/L乙酸铵水溶液(含0.2%甲酸)为流动相梯度洗脱,电喷雾正离子模式电离(ESI+),多反应监测(MRM)模式检测,同位素内标法定量.草甘膦及其代谢物氨甲基膦酸在10~1 000 ng/mL范围内具有良好线性,相关系数均大于0.999,检出限和定量下限分别为0.015 mg/kg和0.05 mg/kg;在不同基质中,0.05,0.1,1.0 mg/kg 3个加标水平的平均回收率为86.6% ~95.7%,相对标准偏差为5.1%~12.2%.该方法具有简便、快速、灵敏度高、准确性强等特点,可用于茶叶中草甘膦及其代谢物氨甲基膦酸残留的快速检测.
A method for the determination of glyphosate (PMG) and aminomethylphosphonic acid (AMPA) residues in tea was developed using dispersive solid-phase extraction (dSPE) combined with high performance liquid chromatography -tandem mass spectrometry( HPLC -MS/MS). The samples were ultrasonically extracted with 0.2% formic acid, and then enriched and cleaned up with Layered Double Hydroxides ( Mg - A1 - LDHs) absorbent. The analytes were derived with fluorenylmethyl- chloroformate(FMOC- C1) in sodium carbonate solution for 2 h. The separation of the target com- pounds were performed on a Phenomenex Kinetex C18 column (50 mm x 2. 1 mm, 2.6 Ixm) using acetonitrile-5 mmol/L ammonium acetate(containing 0. 2% formic acid) as mobile phase by gradi- ent elution. The identification and quantification of the drugs were carried out by positive electrospray ionization(ESI ) in multiple reaction monitoring(MRM) mode, the quantification analysis was per- formed by the isotopically labelled internal standard method. The calibration curves showed good line- arities in the range of 10 - 1 000 ng/mL with correlation coefficients( r2) more than 0. 999. The lim- its of detection(LOD) and the limits of quantitation(LOQ) were 0. 015 mg/kg and O. 05 mg/kg, respectively. The average recoveries of PMG and AMPA in 0. I and 1.0 mg/kg were between 86.6% and 95.7% , different matrices at spiked levels of 0.05, with relative standard deviations(RSDs) of 5. 1% - 12.2% . The developed method is simple, rapid and sensitive, and is suitable for the rapid determination of trace PMG and AMPA residues in tea.
出处
《分析测试学报》
CAS
CSCD
北大核心
2015年第3期335-340,共6页
Journal of Instrumental Analysis
基金
福建省自然科学基金项目(2013J01031)
福建省重点项目(2013Y0001)
出入境检验检疫行业标准制(修)订计划项目(2013B123)
关键词
分散固相萃取
高效液相色谱-串联质谱法
茶叶
草甘膦
氨甲基膦酸
dispersive solid-phase extraction (dSPE)
high performance liquid chromatography - tandem mass spectrometry ( HPLC - MS/MS)
tea
glyphosate
aminomethy|phosphonic acid