【摘要】 提出了测定铬形态的新方法———浊点萃取 电热原子吸收光谱法 (CPE ETAAS)。该法基于利用非离子表面活性剂TritonX 10 0的浊点现象 ,当加热至其浊点时 ,溶液分为两相 ,Cr 与 8 羟基喹啉形成的疏水性螯合物进入富胶束相中 ,从而实现与Cr 的分离。在本法中 ,8 羟基喹啉既作为化学分离 /富集剂 ,又作为ETAAS测定中的化学改进剂。对影响浊点萃取分离的主要因素进行了详细的研究。在最优实验条件下 ,方法测定Cr 的检出限为 0 .0 2 3μg/L ;相对标准偏差为 1.1% (C =2 .0 μg/L ,n =6 )。本法具有简便、灵敏、富集倍数高和避免使用有机溶剂的优点更多还原

【Abstract】 A new method using the cloud point extraction (CPE) technique was developed for the selective determination of chromium species by electrothermal atomic absorption spectrometry (ETAAS). The method is based on the complexation of Cr? with 8-hydroxyquinoline (8-Ox) in Triton X-100 solution, followed by ’in situ’ entrapping of the formed complex in surfactant-rich phase with the temperature higher than cloud point temperature. Thus, the separation of Cr? and Cr? could be realized. The 8-Ox is a chelating agent in CPE and a chemical modifier in ETAAS. The main factors affecting the cloud point extraction were investigated in detail. An enhancement factor of 50 was obtained for the preconcentration of Cr? in 10mL solution. Under the optimal conditions, the detection limit of Cr? is 0.023 μg/L with RSD of 1.1% (n=6, C=2.0 μg/L). The proposed method was applied to the speciation of Cr in lake water with satisfactory results.更多还原