Abstract
The on-line adsorption-concentration of a trace amount of Ce(III) onto a Teflon tube treated by an alkaline solution was investigated for flow-injection analysis (FIA). Several kinds of Teflon tubes were used, and the availability for adsorption was compared. By the fluorometric method with on-line adsorption, Ce(III) could be determined at the concentration range from 0.03 ppb to 10 ppb. The adsorption concentration showed a maximum at a pH between 7 and 10, indicating that the adsorbed species were hydroxide positively charged. 1.5 M HCl 58 μl was used for dissolution of adsorbed species in order to increase the detection intensity. It took two hours to determine 0.03 ppb of Ce(III). The amount of Ce (III) adsorption was 1.5 mg/m2 under the following conditions: inner diameter of Teflon tube, 0.5 mm ; length of the Teflon tube, 3.0 m;10 ppm Ce(III) ; pH 9.7; flow rate, 1.0 ml/min; period of concentration, 20 min.
