流动注射离子交换-分光光度法测定石煤渣中痕量钽

Determination of trace tantalum in stone coal slag with flow injection-ion exchange separation and spectrophotometry

研究了采用流动注射技术进行痕量钽的离子交换分离富集，在0．50mol／L HCl介质中，Ta（Ⅴ）与Cl^-形成络阴离子，被DT-1016阴离子交换树脂交换富集，用0．25mol／LHCl—0．5mol／L硫脲溶液洗脱，用氯磺酚S分光光度法测定。有色络合物的最大吸收波长为570nm。钽的质量浓度在1．1～600μg／L范围内符合比尔定律。经分离后，钽的测定灵敏度可提高数倍，大量共存离子不干扰测定。该法已应用于石煤渣中痕量钽的测定。

A method for the determination of trace tantalum by chlorosulfophenol S spectrophotometry after separation and preconcentration with flow injection ion exchange was studied. In the medium of 0.50 mol/L hydrochloric acid,Ta（Ⅴ） reacts with Cl^- to form a anion complex, which is then adsorbed on the column of DT-1016 anion exchange resin. The anion complex is desorbed from the column with desorption solution of 0.25 mol/L hydrochloric acid - 0.50 mol/L thiourea and tantalum in the desorption solution reacts with chlorosulfophenol S to form a color complex for spectrophotometric determination. The maximum absorption wavelength is 570 nm. Beer＇s law is obeyed in the concentration range of 1.1 - 600 μg/L for tantalum（V）. The sensitivity for the determination of tantalum can be enhanced for several times and a lot of coexisting ions don＇t disturb the determination of tantalum after separation and preconcentration. The method has been applied to the determination of trace tantalum in stone coal slag with satisfactory results.