Analytical Sciences

Abstract − Analytical Sciences, 19(7), 1061 (2003).

Determination of Cadmium in RiverWater by Electrothermal Atomic Absorption Spectrometry after InternalStandardization-Assisted Rapid Coprecipitation with LanthanumPhosphate
Shigehiro KAGAYA,  YusakuHOSOMORI, Hidekazu ARAI, and Kiyoshi HASEGAWA
Department of Applied Chemistry, Facultyof Engineering, Toyama University, Gofuku, Toyama 930-8555,Japan
Cadmium ranging from 1 - 8 ng could becoprecipitated quantitatively with lanthanum phosphate at pH 5 - 6 from upto 200 mL of river water samples spiked with 5 µg of indium as aninternal standard. Cadmium and indium coprecipitated were measured byusing electrothermal atomic absorption spectrometry. The cadmium contentin the original sample solution could be determined by internalstandardization with indium. Since complete collection of the precipitateand strict adjustment of the volume of the final solution aftercoprecipitation are not required in this method, the precipitate could becollected by using decantation and centrifugation, and then dissolved with1 mL of about 2.4 mol L-1 nitric acid. The proposed method issimple and rapid, and enrichment close to 200-times can be attained; thedetection limit (3 σ, n = 6) was 0.63 ng L-1 in 200mL of the sample solution.