Determination of Cadmium in Water by Flame Atomic Absorption Spectrometry after Separation/Preconcentration with Mesoporous Molecule-sieve P123-SH
A new mesoporous molecule-sieve P123-SH was prepared to separation-preconcentration trace cadmium.The conditions for effective adsorption of trace levels of cadmium were optimized and the mechanism of adsorption was discussed.After surging 15 minute at constant room temperature and pH 6.5,the cadmium could be adsorbed quantitatively on mesoporous molecule-sieve P123-SH and the adsorption capacity was 9.52 mg/g.The adsorbed cadmium could be eluted with 2 mol/L HCl from the surface of the sorbent which then was determined by flame atomic absorption spectrometer(FAAS).A linear response of cadmium was obtained in the range of 0.80-120 g/L with a limit of detection of 0.12 g/L.Under optimum conditions,the relative standard deviation(RSD)was 2.1%(n=7,c=50 μg/L).The proposed method has been applied to determine trace cadmium in environmental water with satisfactory results.