Development of preconcentration method for ultra trace analysis

1.建立了电感耦合等离子体质谱同时测定环境水样中锰、钴、镍、铜、安、镉、铅的在线预富集方法。用微处理器控制的高性能四元梯度泵和阀门的半自动系统来引导和输送流动相。该体系包括含有二氧化硅固定的8-羟基喹啉的柱。讨论了样品的pH值和柱上定量洗脱的条件。通过对河流水(SLRS-2)、河口水(SLEW-1)和近岸海水(CASS-2)标准样品的分析，证明了该方法具有良好的精密度和准确度。方法检出限为Cd为7 ng/l，锌为130 ng/l。建立了海水样品中痕量元素的快速分离/预富集方法。用硅胶与Aiquat 336反应制备了动态涂层树脂，吸附了镉、锌等微量元素。用树脂从含0.5-1.0M盐酸的酸化液中定量地捕集镉和锌离子，大多数不同的离子用该方法分离。负载元素用2ml 1M硝酸洗脱。采用石墨炉原子吸收光谱分析和电感耦合等离子体质谱(ICP-MS)测定，方法的检出限为3ppt(Cd)和4ppt(Zn)。

1. An on-line preconcentration method was developed to allow the simultaneous determination of Mn, Co, Ni, Cu, An, Cd and Pb in 5 ml environmental water samples by inductively coupled plasma mass spectrometry. A semiautomated system with a microprocessor-controlled high performance quaternary gradient pump and valves was used to lead and transport the mobile phase. The system includes a column containing silica-immobilized 8-hydroxyquinoline. The pH of samples, and conditions of quantitative elution from column were discussed. The good precision and accuracy of this method are demonstrated by analysing of standard samples of riverine water (SLRS-2), estuarine water (SLEW-1) and coastal seawater (CASS-2). The detection limits of the method range from 7 ng/1 for Cd to 130 ng/1 for Zn.2. A method is developed for the rapid separation/preconcentration of trace elements in seawater samples. Cadmium, zinc and other trace elements are adsorbed on to the dynamically coated resin which was prepared by the reaction of ODS silica with aliquat 336. The cadmium and zinc ions was quantitatively collected on the resin from acidified solution containing 0.5-1.0 M HCI.Most of the diverse ions were separated by this procedure. The loaded elements was eluted by 2 ml of 1M nitric acid. The concentration of the elements was determined by graphite furnace atomic absorption spectroscopy and ICP-MS.The detection limits of the method was 3 ppt for Cd and 4 ppt for Zn, based on 200 ml of seawater samples.