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Studies of speciation and new separation-concentration methods for ultra trace elements in natural water

天然水中超微量元素形态及分离富集新方法研究

基本信息

批准号：
03453039
负责人：
TAGA Mitsuhiko
金额：
$ 4.42万
依托单位：
Hokkaido University
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (B)
财政年份：
1991
资助国家：
日本
起止时间：
1991 至 1992
项目状态：
已结题

项目摘要

A highly sensitive, rapid and facile method of fluorophotometry is described for the determination of phosphate using the ion pair formation of molybdophosphate with Rhodamine 6G. This ion pair is collected on the membrane filter made of cellulose nitrate when the sample solution is adjusted to 0.35 mol dm^<-3> in sulfuric acid, 1.9 mmol dm^<-3> in ammonium molybdate and 3.1 mumol dm-3 in Rhodamine 6G, and it is filtered through the membrane filter under suction. The membrane filter together with the ion pair is dissolved into Methyl Cellosolve. The fluorescence intensity of this solution is measured at 555 nm with the excitation at 535 nm. The calibration curve of phosphate is linear from 5 to 100 ng of phosphate(n=12). Although arsenic(V) causes positive error, no ions, including silicate, commonly existing in natural water interfere with the determination of phosphate. The proposed method was applied to the determination of phoshate-phosphorus in water samples and satisfactory resul … More ts were obtained.Accumulation voltammetry of copper(II) at a chemically modified carbon paste electrode(CMCPE) containing 2-(Salicylideneamino)thiophenol was studied. Copper(II) was accumulated as the complex on the electrode based on the chemical reaction without the applied potential. The reduction peak of the complex was observed. The calibration curve of copper(II) was linear over the range of 10^<-9>-10^<-7> M. The proposed method was applicable to the determination of copper(II) in standard reference materials prepared by the National Institute for Environmental Studies, and the results were acceptable.In order to clarify the relation ship between functional groups and copper(II) binding sites in humic acids, pH and conductimetric titration curves of humic acids were compared with those of the model compounds (EDTA, phenylalanine, citric acid and hydroxyhydRoquinone). Moreover, the kinds of functional groups in humic acids were identified by the data obtained from element analysis and FT-IR spectra. Furthermore, effect of ionic strength on the copper(II) complexing abilities of humic acid was investigated. Less

本文提出了一种高灵敏、快速、简便的测定磷酸根的荧光光度法。当样品溶液在硫酸中被调节至0.35 mol dm-3、在氯化铵中被调节<-3>至1.9 mmol dm-3<-3>、在罗丹明6 G中被调节至3.1 μ mol dm-3时，该离子对被收集在由硝酸纤维素制成的膜过滤器上，并在抽吸下通过膜过滤器过滤。将膜过滤器与离子对一起溶解于甲基溶纤剂中。该溶液的荧光强度在555 nm处测量，激发波长为535 nm。磷酸盐的校准曲线在5 - 100 ng磷酸盐范围内呈线性（n=12）。虽然砷（V）会引起正误差，但天然水中常见的离子（包括硅酸盐）不会干扰磷酸盐的测定。方法用于水样中磷酸根的测定，结果满意 ...更多信息研究了Cu（Ⅱ）在2-（水杨醛缩氨基）苯硫酚化学修饰碳糊电极（CMCPE）上的富集伏安法。铜（II）在没有施加电势的情况下基于化学反应在电极上作为络合物积累。观察到络合物的还原峰。铜（II）的标准曲线在10 μ <-9>M-10 μ <-7>M范围内呈线性关系。为了明确胡敏酸中Cu（II）结合位点与功能基团的关系，将胡敏酸的pH和电导滴定曲线与模型化合物进行了比较（EDTA、苯丙氨酸、柠檬酸和羟基氢醌）。通过元素分析和红外光谱分析确定了胡敏酸中的官能团种类。研究了离子强度对胡敏酸络合铜离子能力的影响。少