离子色谱-电感耦合等离子体质谱法测定玩具涂层中可迁移六价铬

Determination of transportable hexavalent chromium in coatings on toys by ion chromatography–inductively coupled plasma mass spectrometry

建立了离子色谱-电感耦合等离子体质谱法快速测定玩具涂层中可迁移六价铬的方法。样品经0.07 mol/L盐酸溶液浸泡,提取其中痕量的可迁移六价铬,离子色谱分离后进行电感耦合等离子体质谱法测定。考察了色谱流动相的种类、p H和浓度以及进样体积对六价铬的保留时间及其分离效果的影响。当采用75 mmol/L、p H为8.5的硝酸铵溶液为流动相,进样量为200μL时,三价铬和六价铬可达到最佳分离。该方法的线性相关系数大于0.999,六价铬的检出限为0.005μg/L。在0.05、0.2和0.5μg/L的加标水平下,平均回收率为95.8%~102.4%,相对标准偏差小于4.2%,满足欧盟玩具安全新指令2009/48/EC的检测要求。

A method for rapid determination of transportable hexavalent chromium in coatings on toys by ion chromatography （IC）-inductively coupled plasma mass spectrometry （ICP-MS） was established. Trace amount of the transportable hexavalent chromium in a sample are extracted by immersing in 0.07 mol/L hydrochloric acid, separated by IC, and then detected by ICP-MS. The effects of chromatographic parameters including the type. pH and concentration of the mobile phase as well as injection volume on retention time of hexavalent chromium and its separation were studied. The optimal separation of trivalent and hexavalent chromium is achieved for a sample of 200 μL when using a 75 mmol/L NH4NO3 solution at pH 8.50 as mobile phase. The method has a linear correlation coefficient over 0.999 and a detection limit of 0.005 μg/L. The average recoveries range from 95.8% to 102.4% for the spikes of 0.05 μg/L, 0.2 μg/L and 0.5 μg/L with a relative standard deviation lower than 4.2%, meeting the determination requirements of Directive 2009/48/EC of the European Parliament and of the Council on the safety of toys.