搅拌棒吸附萃取-电感耦合等离子体质谱分析水样中无机铬的形态

Stir Bar Sorptive Extraction Combined with Inductively Coupled Plasma Mass Spectrometry for the Speciation of Inorganic Chromium in Water Samples

采用溶胶-凝胶法制备了3-（2-氨基乙氨基）丙基三甲氧基硅烷（AAPTS）-聚二甲基硅氧烷（PDMs）涂层搅拌棒，考察了Cr（Ⅲ）／Cr（VI）在自制AAPTS～PDMS涂层搅拌棒上的吸附行为，优化了影响搅拌棒吸附萃取（SBSE）的主要实验参数。基于此，建立了SBSE-等离子体质谱（ICP—MS）联用分析环境水样中无机铬形态的新方法。在最佳实验条件下，该方法对Cr（Ⅵ）的检出限（3a）为0．0014ug／L，线性范围为0．01～2000μg／L，相对标准偏差（RSD）为6．4％（c—10μg／L，72—7），实际富集倍数为6．9倍。N-该方法应用于水样中无机铬的形态分析，结果满意．

A novel 3- （ 2-aminoethylamino ） propyltrimethoxysilane （ AAPTS）-polydimethylsiloxane （PDMS）coating was prepared by sol-gel method. The adsorption behavior of Cr（ llI） and Cr（VI） on the prepared coating was investigated by stir bar sorptive extraction（SBSE） and it was found that Cr（VI） could be selectively retained on the coating in the pH range of 3- 9, while Cr （ HI ） could not be retained in the studied pH range. Based on it,a simple and sensitive method combining SBSE with inductively coupled plasma mass spectrometry detection was developed for the speciation of inorganic chromium in water samples. Under the optimized condition, the detection limit of the proposed method for Cr （VI） was 0. 0014 μg/L with RSD of 6.4%（c=10 μg/L,n=7）. The linear range of Cr（gI） was 0.01-2 000 μg/L.