Ibnu Sina Institute for Fundamental Science Studies, Universiti Teknologi Malaysia, 81310 UTM Skudai, Johor, Malaysia.
J Chromatogr A. 2010 Sep 10;1217(37):5832-8. doi: 10.1016/j.chroma.2010.07.054. Epub 2010 Jul 23.
A dynamic supported liquid membrane tip extraction (SLMTE) procedure for the effective extraction and preconcentration of glyphosate (GLYP) and its metabolite aminomethylphosphonic acid (AMPA) in water has been investigated. The SLMTE procedure was performed in a semi-automated dynamic mode and demonstrated a greater performance against a static extraction. Several important extraction parameters such as donor phase pH, cationic carrier concentration, type of membrane solvent, type of acceptor stripping phase, agitation and extraction time were comprehensively optimized. A solution of Aliquat-336, a cationic carrier, in dihexyl ether was selected as the supported liquid incorporated into the membrane phase. Quantification of GLYP and AMPA was carried out using capillary electrophoresis with contactless conductivity detection. An electrolyte solution consisting of 12 mM histidine (His), 8 mM 2-(N-morpholino)ethanesulfonic acid (MES), 75 microM cetyltrimethylammonium bromide (CTAB), 3% methanol, pH 6.3, was used as running buffer. Under the optimum extraction conditions, the method showed good linearity in the range of 0.01-200 microg/L (GLYP) and 0.1-400 microg/L (AMPA), acceptable reproducibility (RSD 5-7%, n=5), low limits of detection of 0.005 microg/L for GLYP and 0.06 microg/L for AMPA, and satisfactory relative recoveries (90-94%). Due to the low cost, the SLMTE device was disposed after each run which additionally eliminated the possibility of carry-over between runs. The validated method was tested for the analysis of both analytes in spiked tap water and river water with good success.
一种动态支撑液膜尖端萃取（SLMTE）程序，用于有效地萃取和预浓缩水中的草甘膦（GLYP）及其代谢物氨甲基磷酸（AMPA）。SLMTE 程序以半自动动态模式进行，并表现出比静态萃取更好的性能。全面优化了几个重要的萃取参数，如供体相 pH 值、阳离子载体浓度、膜溶剂类型、接受相剥离相类型、搅拌和萃取时间。选择 Aliquat-336 作为阳离子载体的二己基醚溶液作为包含在膜相中的支撑液。使用毛细管电泳非接触式电导检测对 GLYP 和 AMPA 进行定量。含有 12 mM 组氨酸（His）、8 mM 2-（N-吗啉）乙磺酸（MES）、75 microM 十六烷基三甲基溴化铵（CTAB）、3%甲醇、pH 值 6.3 的电解质溶液用作运行缓冲液。在最佳萃取条件下，该方法在 0.01-200 μg/L（GLYP）和 0.1-400 μg/L（AMPA）范围内表现出良好的线性关系，可接受的重现性（RSD 5-7%，n=5），草甘膦的检出限低至 0.005 μg/L，氨甲基磷酸的检出限低至 0.06 μg/L，相对回收率令人满意（90-94%）。由于成本低，每次运行后都会处理 SLMTE 设备，这进一步消除了运行之间交叉污染的可能性。该经过验证的方法成功地用于分析加标自来水和河水样品中的两种分析物。
