University of Tehran Journal of Sciences, Islamic Republic of Iran 1016-1104 11 1 2000 03 01 EXTRACTIVE-SPECTROPHOTOMETRIC DETERMINATION OF VANADIUM(V) AS AN ION-ASSOCIATION COMPLEX WITH 4-(2-PYRIDYLAZ0)-RESORCINOALN D TETRABUTYLAMMONIUM PERCHLORATE - 31299 EN Journal Article A simple and sensitive extractive- spectrophotometric method for thedeterrnination of trace amounts of vanadium(V) is reported. The method is based on the quantitative extraction of the anion complex of V(V) with 4-(2-pyridy1azo)-resorcinol with tetrabutylammonium perchlorate into chloroform, followed by spectrophotometric measurements at 554 nm. Beer's law is obeyed over the concentration range of 5-350ng m l at 554 nm with a molar absorptivity of 1 . 3 1m ol cm . The relative standard deviation is 1.6% for a 100 ng ml vanadium solution. The interfering effect of various cations and anions was studied. The method was applied to thedeterrnination of vanadium is some synthetic samples https://jsciences.ut.ac.ir/article_31299_9a9e0713c813c15dac6e857cd7e33e05.pdf