[Study on the adsorption capability of barium-strontium titanate powder coated with dithizone for cadmium ion in water].
Barium-strontium titanate (BST) powder was prepared by using oxalate coprecipitate method, and the surface of barium-strontium titanate (BST) powder was modified by coating with dithizone, gaining a new sort of sorbent. FTIR analysis was used for characterizing the surface modification. By means of determination with flame atomic absorption spectrometry (FAAS), the adsorption capability of cadmium on the coating BST powder was investigated, and the condition of elution was observed; studies of coating and adsorption mechanism were also performed. The results showed that dithizone coated on the BST powder throngh hydrogen bonding between the hydroxyl groups and oxygen atoms on surface of the BST and dithizone. The cadmium ion in water could be adsorbed quantitively on dithizone coated BST when the pH was 6.0. At room temperature, the adsorption equilibrium could be obtained in 20 min. 5% EDTA was sufficient for complete elution. A new method for the determination of trace cadmium based on dithizone coated BST separation/ preconcentration and FAAS determination was proposed. The detection limit of this method for cadmium ion was 0.2 microg x L(-1), and the RSD was 2.9%. The method has been applied to the determination of trace cadmium ion in water samples with satisfactory results.
School of Environmental and Chemical Engineering, Shenyang Ligong University, Shenyang 110168, China. zhangdong1186@sina.com
Dong
D
Zhang
Hui-Dong
HD
Su
Hong
H
Gao