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Hydroxy naphthol blue as a spectrophotometric and fluorometric reagent for the uranyl ion

Journal Article · · Anal. Lett.; (United States)

The utility of hydroxy naphthol blue (HNB) as a spectrophotometricallows and fluorometric reagent for the uranyl ion has been investigated. In phthalate buffer (at a pH of 4.0), UO/sub 2//sup 2 +/ forms a brown complex of low absorptivity with the red form of HNB. By following the decrease in HNB absorbance at 530 nm (which has element of = 4.1 x 10/sup 3/) uranyl ion can be determined to levels as low as 1.1 x 10/sup -6/ M (0.30 ..mu..g/ml). HNB also emits at 460 nm when excited at 365 nm at these pH values, while the UO/sub 2//sup 2 +/ complex exhibits greatly reduced emission. Examination of the quenching of HNB emission by UO/sub 2//sup 2 +/ allows the determination of uranyl ion to levels as low as 3.2 x 10/sup -6/ M (0.86 ..mu..g/ml). A 1:1 type complex was formed between UO/sub 2//sup 2 +/ and HNB, and a formation constant of 9.77 x 10/sup 3/ (log K/sub 1/ = 3.99) was measured for the complex.

Research Organization:
Ferrum Coll., VA
OSTI ID:
7143618
Journal Information:
Anal. Lett.; (United States), Journal Name: Anal. Lett.; (United States) Vol. 10:4; ISSN ANALB
Country of Publication:
United States
Language:
English