A STUDY OF A HIGHLY SENSITIVE COLOUR RE ACTION OF UO_2~(2+) -3-YRIDINECARBOXYLIC ACID- BY THE FORMATION OF ASSOCIATED COMPOUND WITH ETHYL VIOLET

It is found that in the medium of sulfuric acid pyridyl-3-uranyl formate complex anion reacts with ethyl violet cation to form an associated compound with blue colour. This complex can be extracted within 1 minute into a 10 ml mixture of benzene and MIBK in the ratio of 3 to 1 by volume and has a maximum absorption at 604 nm. The molar absorption coefficient is 3.6×106 l·-mol-1·cm-1. The main conditions for extraclion-spectrophotometric method are investigated in detail.