Use of dye aggregation phenomenon for spectrophotometric and SIA-LAV determination of bismuth(III) as a specific ion association complex between tetraiodobismuthate and Astra Phloxine

A simple, rapid, highly sensitive and selective non-extraction spectrophotometric sequential injection analysis with lab-at-valve (SIA-LAV) methods for the determination of bismuth(III) have been developed based on formation a specific ion association complex (IA) between tetraiodobismuthate(III) anion polymethine dye Astra Phloxine (AP). The changes in absorption spectra resulting from IA are explained framework exciton theory by aggregation ions. analytical wavelength was chosen region an intense narrow bathochromically shifted band maximum at 600 nm related to aggregated IA. It shown that any cationic dye, including representatives triphenylmethane, rhodamine dyes, is capable forming IAs. One most important prerequisites its relatively low solubility. UV–visible spectrum AP cation calculated using time-dependent density functional (TD-DFT). Superiority TD-DFT Franck-Condon approximation, which takes into account vibronic effects, over traditional non-vibrationally resolved calculations. PBE1PBE suitable comparison used M06, CAM-B3LYP, WB97XD M11 functionals. Carrying out chemical reaction mixing external chamber allowed conditions be adapted requirements necessary complete Thus, possible sensitivity achieved, about order magnitude higher than when classical SIA approach. Calibration ranges detection limits (indicated parentheses) SIA-LAV procedures were 0.04–0.5 (0.01) 0.1–1.7 (0.03) mg L−1, respectively. molar absorptivity Sandell's found 6.6 × 104 mol−1 L cm−1 3.16 10−3 μg cm−2, proposed successfully applied bismuth content pharmaceutical compositions alloys.