Abstract
A simple strategy has been developed for determination and speciation of bismuth(III) & (V) coupled dual wave beta-correction spectrophotometry. The principle of the study was based on the reaction of bismuth(III) with reagent 1-(o-arsonophenylazo)-2-napthol-3,6-disulphuric acid (Thorin-I) to form a deep red orange colored complex species. The absorbance intensity was recorded at lambda(max) = 540 nm. The method exhibits a wide linear range (0.25-20.0 mu g mL(-1)) and Ringbom's plots in the range 1.6-10.0 mu g mL(-1) for bismuth(III) ions, respectively. The lower limit of detection (LOD) and quantification (LOQ) obtained were 0.045 and 0.15 mu g mL(-1), respectively. Bismuth(V) was determined after reduction to bismuth(III) with Mn2+ in acidic solution. Trace level speciation studies were performed with satisfactorily recovery percentages for bismuth species. The method was applied for analysis of total bismuth in tap water, well water, marine water, hair sample, pharmaceutical formulations (cream) and in certified reference material (IAEA Soil-7). The results were compared successfully in terms of F and t-test with the reference method inductively coupled plasma-mass spectrometry(ICP-OES) and no significant difference was noticed at 95% confidence (P = 0.05). The developed method has a unique advantage to be quantitatively applied to a variety of samples due to rapid response, short analytical time and ability to be detected by naked eye with good reproducibility. The LOD offered has a value lower than that recommended by World Health Organization (WHO) and compared successfully with some reported spectrochemical and electrochemical methods. (C) 2017 Elsevier B.V. All rights reserved.