Abstract
The spectrophotometric study was made of red-violet 1, 3-cyclohexanedione bis-thiosemicarbazone-Bi (III) in an acidic dimethylformamide-water solution (λmax = 540 nm, ∊ = 3.3 × 10−4 1. mol−1. cm−1, stoichiometry 3:1, apparent stability constant (6.0 × 1010). A new method for the spectrophotometric determination of Bi (III) is proposed for concentrations between 0.7 and 7.4 ppm. The relative error (95 % confidence level) is 0.5 % for 3.7 ppm of Bi (III).
The extraction with methyl isobutyl ketone of the red-violet complex was also studied spectrophotometrically (λmax = 550 nm, ∊ = 3.34 × 104 1. mol−1.cm−1, stoichiometry 2:1). A new method for the extraction-spectrophotometric determination of Bi (III) is proposed for concentrations, in aqueous phase, between 0.2 and 1.2 ppm. The relative error (95 % confidence level) is 0.8 % for 0.9 ppm of Bi (III).
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