二苯甲酰甲烷-磷酸三丁酯增塑泡塑富集光度法测定水中痕量铀

PHOTOMETRIC DETERMINATION OF TRACE AMOUNTS OF URANIUM IN WATER AFTER ITS PRECONCENTRATION ON FOAM-PLASTIC PLASTICIZED WITH TRIBUTYLPHOSPHATE (TBP) AND COATED WITH DIBENZOYLMETHANE (DBM)

研究制备了对铀有良好吸附性能的涂二苯甲酰甲烷(DBM)-磷酸三丁酯(TBP)增塑聚氨酯泡沫塑料。该增塑泡塑在pH6.5时可快速定量吸附水溶液中痕量铀,饱和吸附量为120μg/g增塑泡塑。用0.6mol·L-1盐酸20mL可定量洗脱色谱柱中10μg的铀,常见阳离子不干扰铀的吸附及洗脱。建立的泡塑富集光度法可准确测定环境水中痕量铀,具有高效灵敏的特点。

The polyurethane foam-plastic is modified by coating with DBM and plasticizing with TBP, and the modified foam-plastic is found to have excellent adsorptivity to uranium ion. Uranium ion is adsorbed on the foam-plastic from a solution of pH 6. 5, and the adsorption equilibrium is attained within 5 min. The saturated adsorption capacity is found to be 120 μg per gram of the foam-plastic when the equilibrium concentration of uranium is 28 mg·L-1. Under the optimum conditions, quantitative recovery (>90%) is achieved by adsorption of uranium ion having a concentration of 0. 01 g·L-1 on 1 g of the modified foam plastic. Hydrochloric acid having a concentration of 0. 6 mol·L-1 is used to desorb uranium ion from the foam-plastic, and 20 mL of 0. 6 mol·L-1 HC1 is required to desorb 10 μg of uranium from 0. 1 g of foam-plastic. Photometric determination is carried out with arsenazoⅢ as chromogenic reagent under the conventional conditions. Common co-existing ions have no interference to the determinatioa The proposed method has been applied to the determination of trace amounts of uranium in water samples.