测定海水中的Li、Rb、B、Sr不需要像痕量元素一样采用复杂的分离富集方法,去除基体元素,富集目标元素,而是直接将海水稀释50倍,优化电感耦合等离子体质谱(ICP-MS)参数,提高测试灵敏度后,在线加入内标Re上机测试, Li、Rb、B、Sr的方法检测限(3σ)分别为0.75,0.25,14.0和0.10μg/L。连续测试10次海水样品,计算相对标准偏差(RSD), Li为1.47%, B为3.13%, Rb为2.05%, Sr为2.01%；并进行加标回收率实验,回收率在96.5%~105%之间。结果表明,该操作简单,测定速度快,数据稳定,可靠,满足海水中这4种元素的测试要求。测定了大西洋底层海水(距离海底200 m)中这4种元素,数据偏差小于2.65%,低于方法测试标准偏差,该层位水体稳定,无变化。%Determination of Li, Rb, B and Sr in seawater does not need to use complicated methods used for deter-mination of trace elements in seawater such as chelation-separation and standard addition calibration. It can be performed briefly by diluting seawater by 50 times directly, tuning the sensitivity of Inductively Coupled Plasma Mass Spectrometry (ICP-MS) and adding internal standard Re on line. The examination limit (3σ) for Li, Rb, B and Sr was 0.75, 0.25, 14.0 and 0.10 μg/L respectively. After 10 times continuous determination of seawater samples, the relative standard deviation (RSD) was calculated:the RSD of Li was 1.47%, B was 3.13%, Rb was 2.05%and Sr was 2.01%. The standard was added to assess the recovery of experimentand the recovery rate was from 96.5%to 105%. The results show that this method is simple, fast, and the data is stable, accurate and reliable, which well met the requirement for determination of these elements in seawater. We have measured these four elements in Atlantic bottom water (from the Underwater at 200 meters). The data deviation was less than 2.65%, which was lower than the standard deviation of the method. The seawater in this layer is steady and there is no change.
展开▼
