高效液相色谱-电感耦合等离子体质谱联用技术测定玩具中痕量可迁移Cr(Ⅵ)

Determination of Trace Migratory Chromium(Ⅵ) in Toys 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联用技术(HPLC-ICP-MS)测定玩具中痕量可迁移Cr(Ⅵ)的方法。采用Dionex AS19分析柱,在流动相为NH4NO3,pH=7.4,流速为1.0 mL/min的条件下,可以很好地分离Cr(Ⅲ)和Cr(Ⅵ),且流动相浓度越小,分离度越大。所建立的方法简便、快速、灵敏度高,在色谱进样量为100μL,质谱采用He碰撞池模式下,对Cr(Ⅵ)的检出限为0.02μg/L;两个加标水平0.50和5.00μg/L回收率分别为98.8%～104.2%和96.3%～100.4%,方法精密度优于4.2%,可以满足测定要求。应用本方法测定了玩具可接触部分材料包括涂层、塑料、木料、织物中的可迁移Cr(Ⅵ),分析结果令人满意。

A method for determinating trace migratory chromium（WI） in toys by hyphenated technique of high performance liquid chromatography-inductively coupled plasma mass spectrometry （HPLC-ICP-MS） has been developed in this article. The chromium species Cr（Ⅲ） and Cr（VI） were separated on an Dionex AS19 analysis column using ammonium nitrate as the mobile phase with pH 7. 4 at flow rate 1. 0 mL/min. And the chromatographic separation was increased as the concentration of mobile phase was decreased. This method was easy to operate and with remarkably high sensitivity. The detection limit was found to be 0.02 μg/L of Cr（VI） for 100 μL injection volume in He collision cell mode of mass spectrometry. The spiked recoveries were at the range of 98.8%-104.2% and 96.3%-100.4% for the spiked levels of 0.50 μg/L and 5.00 μg/L respectively, and the RSDs were less than 4.2%, which met the determination requirements. This method has been used to determine migratory Cr（VI） in accessible parts of toys, including coating, plastic, wood and textile. The results were satisfactory.