便携式电动流动分析系统同时富集测定矿泉水中铬(Ⅵ)和镉(Ⅱ)

Application of Portable Electrokinetic Flow Analysis System for Determination of Chromium(Ⅵ) and Cadmium(Ⅱ) in Mineral Water

研究了电渗泵性能的改进以及双向电堆积系统各种参数对富集倍数的影响。提出一种电渗驱动与双向电堆积相结合的便携式电动流动分析系统 ,并采用石墨炉原子吸收法对矿泉水中铬 和镉 进行了同时富集和测定。检出限为 9ng/LCr 和 10ng/LCd (n =11,3倍空白标准偏差 )。加入相当于样品含量的Cr 和Cd ,回收率分别为 (10 5～ 10 7)± 2 %和 (10 4～ 10 6 )± 2 % (n =3)

The improvement of the electroosmotic pump properties and the effects of the bi directional electrostacking system on the pre concentration factor were investigated. A portable electrokinetic flow analysis system with electroosmotic driving and bi directional electrostacking unit was introduced. The improved system with graphite furnace atomic absorption spectrometry was employed to separate, pre concentrate and determine Cr? and Cd? in mineral water. The detection limit of Cr? and Cd? was 9 ng/L and 10 ng/L (3σ of blank, n =11), respectively. Their recoveries of 200 ng/L Cr? and 100 ng/L Cd? added to samples were (105～107)±2% and (104～106)±2%( n =3).