Statistically designed extractive spectrophotometric determination scheme for bismuth(III) with 2-chlorobenzaldehyde thiocarbohydrazone: Analysis of environmental and real resources

Abstract

The principle of liquid-liquid extraction followed by spectrophotometric determination of bismuth(III) was elaborated. The yellow complex of bismuth(III) with 2-chlorobenzaldehyde thiocarbohydrazone in presence of potassium iodide is soluble in chloroform and was extracted from HCl-KCl buffer having pH 1.2. The concentration of 2-chlorobenzaldehyde thiocarbohydrazone and potassium iodide ensuring maximum absorbance were optimized well. The effect of foreign ions was also thoroughly elucidated. The maximum absorbance of the complex is witnessed at 420 nm having the values of molar absorptivity and Sandell's sensitivity as 1.086 × 10 4 L mol −1 cm −1 and 0.01923 µg cm −2 , respectively. The Beer's law is obeyed for bismuth(III) concentrations over the range of 4.80 to 16.0 μg mL −1 . The composition of [Bi(III)-2CBTCH-iodide] complex was found to be 1:1:1. The scheme has been applied for the determination of bismuth(III) in environmental and real resources.