基于铌能与二甲酚橙形成红色络合物的特点,利用分光光度技术;试样以王水溶解,高氯酸或硫酸冒烟,加氢氟酸使铌与氟生成稳定的络合物(H7Nb F7)在0.18N的盐酸介质中与二甲酚橙生成红色络合物,借此进行比色测定,过量的氟离子用硫酸铍或硫酸铝消除,锆可用CYDTA掩蔽。 Based on the characteristic that niobium can form red complex with xylenol orange, spectrophotometry was used. The sample was dissolved with aqua regia, smoked with perchloric acid or sulfuric acid, hydrofluoric acid was added to make stable complex between niobium and fluorine (H7Nb F7) generates a red complex with xylenol orange in a 0.18 N hydrochloric acid medium whereby a colorimetric assay is performed, excess fluoride is eliminated with beryllium sulfate or aluminum sulfate and the zirconium can be masked with CYDTA.