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

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( Cd2+)的方法。浸提液为10 mmol/L Tris-HCl缓冲溶液,加入0.1 mol/L NaCl(pH 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Cd2+分离；流动相组成为50 mmol/L草酸和95 mmol/L LiOH。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Cd2+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。

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

Abstract A new method was established to determine the free inorganic cadmium ion ( Cd2+) in marine bivalves using high performance liquid chromatography and inductively coupled plasma mass spectrometry ( HPLC-ICP-MS) . The free Cd2+ 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 Cd2+ was achieved using an IonPac CS5A analytical column with an IonPac CG5A guard column. The mobile phase consisted of 50 mmol/L C2 H2 O4 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 Cd2+ were all above 84. 6%. The free Cd2+ content in several kinds of marine bivalves was determined using the method and the results showed that the percentage of free inorganic Cd2+ to the total Cd content in samples with high Cd content was higher than those with low Cd content.