Tasuku Akagi

Simultaneous multi-element determination of trace metals in sea water by inductively-coupled plasma atomic emission spectrometry after coprecipitation with gallium

Abstract Coprecipitation with gallium hydroxide is studied for the preconcentration of trace metals in sea water before multi-element analysis by inductively-coupled plasma/atomic emission spectrometry. Gallium precipitates at pH 9 only when magnesium is present. Optimum conditions are established for multi-element preconcentration and removal of matrix elements. The method is almost free from contamination because of the use of highly pure gallium meetal and only a small amount of sodium hydroxide for pH adjustment. Spectral interferences from gallium are negligible and a concentratioin factor of more than 200 can be obtained. Detection limits range from a few ng l−1 to 150 ng l− for Al, Co, Cr, Fe, La, Mn, Ni, Ti, V, Zn, Y and Pb. Artificial and natural sea-water samples can be analyzed with adequate precision.

Simultaneous multi-element analysis for trace metals in sea water by inductively-coupled plasma/atomic emission spectrometry after batch preconcentration on a chelating resin☆

Abstract Batch treatment with Chelex-100 resin was investigated for preconcentration of trace metals in sea water followed by determination by inductively-coupled plasma atomic emission spectrometry. The preconcentration conditions such as resin weight, stirring time, and amount of ammonium acetate buffer solution were carefully examined for effective multi-element preconcentration from sea water. The resin weight could be decreased to 0.5 g (dry weight) for 1 l of sea water, which was much less than that required in the column method, and a preconcentration factor of 100 was achieved. Al, Ti, V, Mn, Fe, Co, Ni, Cu, Zn, Y, Mo, Cd and Pb in sea water were measured with good precision. The detection limits ranged from 6 to 180 ng l −1 . The time required for one sample by the batch method was only 3 h.

Zirconium coprecipitation for simultaneous multielement determination of trace metals in seawater by inductively coupled plasma atomic emission spectrometry

Zirconium coprecipitation for simultaneous multielement determination of trace metals in seawater has been examined by inductively coupled plasma atomic emission spectrometry. Optimum pH conditions and other experimental procedures for coprecipitation were investigated in order that the method for multielement preconcentration could be evaluated. The concentration factor of 20 times the original concentration was obtained, although it was limited by spectral interference with zirconium. The present coprecipitation method improves the detection limits and other analytical figures of merit for 17 trace metals (Al, As, Cd, Co, Cr, Cu, Fe, La, Mn, Mo, Ni, Pb, Sb, Ti, V, Y, and Zn), which were estimated by the use of artificial seawater samples, and it was applied to natural seawater analysis.