高效液相色谱-电感耦合等离子体质谱法测定海水贝类中无机离子镉

Determination of Free Inorganic Cadmium Ions in Marine Bivalves by High Performance Liquid Chromatography-Inductively Coupled Plasma Mass Spectrometry

建立了高效液相色谱-电感耦合等离子体质谱法(HPLC-ICP-MS)测定贝类中无机镉离子(Cd^(2+))的方法。浸提液为10 mmol/L Tris-HCl缓冲溶液,加入0.1 mol/L Na Cl(p H 7.5);样品经超声提取40 min,CG5A阳离子保护柱和CS5A阳离子分析柱对样品中Cd^(2+)分离;流动相组成为50 mmol/L草酸和95 mmol/L Li OH。本方法线性良好,相关系数R=0.999,回收率高于84.6%。采用本方法分析了我国几种常见海产贝类中Cd^(2+)的含量,发现总Cd含量高的样品中无机离子态Cd所占的百分比普遍高于总Cd含量低的样品。

Abstract A new method was established to determine the free inorganic cadmium ion （ Cd^2＋） in marine bivalves using high performance liquid chromatography and inductively coupled plasma mass spectrometry （ HPLC-ICP-MS） . The free Cd^2＋ in shellfish was ultrasonic extracted for 40 min by 10 mmol/L Tris buffer solution （ with 0. 1 mol/L NaCl, pH=7. 5）, and the separation of Cd^2＋ was achieved using an IonPac CS5A analytical column with an IonPac CG5A guard column. The mobile phase consisted of 50 mmol/L C2 H2O4 and 95 mmol/L LiOH. The new method had a good linear relationship with the correlation coefficient of 0. 999 and the standard recoveries of Cd^2＋ were all above 84. 6%. The free Cd^2＋ content in several kinds of marine bivalves was determined using the method and the results showed that the percentage of free inorganic Cd^2＋ to the total Cd content in samples with high Cd content was higher than those with low Cd content.