Yokoyama Yukio, Danno Takenobu, Haginoya Mizuki, Yaso Yukari, Sato Hisakuni
Department of Analytical Chemistry, Faculty of Engineering, Yokohama National University, 79-7 Tokiwadai, Hodogaya, Yokohama 240-8501, Japan.
Talanta. 2009 Jul 15;79(2):308-13. doi: 10.1016/j.talanta.2009.03.053. Epub 2009 Apr 1.
A highly sensitive HPLC method for the simultaneous determination of soluble silicate and phosphate in environmental waters was developed, using ion-pair liquid chromatography preceded by the formation of their yellow alpha-heteropolymolybdates. The moderate-pH mobile phase enabled to use a highly efficient reversed-phase silica column. The pre-column coloring reactions at moderate-pH were reproducible for both silicate and phosphate in all quantification ranges with R.S.D.s less than 2% and 5%, respectively. The linear calibration lines between concentrations (mg-SiO(2)/L and mg-PO(4)/L) and peak area intensities were obtained for silicate and phosphate both with acceptable determination coefficients (r(2)) of 0.9999. The limits of determination for both analytes were 0.007 mg-SiO(2)/L and 0.003 mg-PO(4)/L, which were calculated theoretically using 10sigma/slope. The four-digit dynamic ranges were obtained for 0.007-10mg-SiO(2)/L and 0.003-20mg-PO(4)/L. The developed method was applied for the analysis of tap water, river water, coastal seawater, well water, hot-spring water, commercial mineral water, and laboratory water. The results were very reasonable and acceptable from the environmental viewpoints, which were well correlated with those confirmed by the molybdenum-blue spectrophotometry.
建立了一种高灵敏度的高效液相色谱法，用于同时测定环境水中的可溶性硅酸盐和磷酸盐，该方法采用离子对液相色谱法，先将它们形成黄色的α-杂多钼酸盐。中等pH值的流动相使得能够使用高效反相硅胶柱。中等pH值下的柱前显色反应在所有定量范围内对硅酸盐和磷酸盐都是可重现的，相对标准偏差分别小于2%和5%。硅酸盐和磷酸盐的浓度（mg-SiO₂/L和mg-PO₄/L）与峰面积强度之间均获得了线性校准曲线，测定系数（r²）均为0.9999，可接受。两种分析物的测定限分别为0.007 mg-SiO₂/L和0.003 mg-PO₄/L，这是使用10σ/斜率理论计算得出的。获得了0.007 - 10mg-SiO₂/L和0.003 - 20mg-PO₄/L的四位数字动态范围。所开发的方法应用于自来水、河水、沿海海水、井水、温泉水、商业矿泉水和实验室用水的分析。从环境角度来看，结果非常合理且可接受，与钼蓝分光光度法确认的结果相关性良好。
