Citation: Zhang Hongqin , Xu Shengjie . Studies on Superhigh Sensitive Colour Reactions and Their Applications Ⅴ.Tungsten-Ethyl Rhodamine B-Thiocyanate System. Chinese Journal of Analytical Chemistry, 1990, 18(11): 987-991. [復制]
Studies on Superhigh Sensitive Colour Reactions and Their Applications Ⅴ.Tungsten-Ethyl Rhodamine B-Thiocyanate System
A highly sensitive spectrophotometric method has been developed for the datermination of trace tungsten based on the formation of a complicated ion-association complex of tungsten with ethyl rhodamine B and thiocyanate in the presence of polyvinyl alcohol-124.The maximum absorption of the ion-association complex is at 585 nm and its apparent molar absorptivity is 1.9×106 L·mol-1·cm-1.Beet's law is obeyed for tungsten in the range of 0～1.5 μg/25 ml.The interference of 31 diverse ions was studied.The proposed methcd has been used for the determination of trace tungsten in steel and water samples with satisfactory results.