Extraction-spectrophotometric determination of gallium with 1,2,4,6-tetraphenylpyridinium perchlorate
Abstract
The characteristics and applications of 1,2,4,6-tetraphenylpyridinium perchlorate (TPPP) as a reagent for the spectrophotometric determination of gallium are described. This reagent forms a 1 : 1 complex with GaCl4-(λmax. 310 nm, molar absorptivity 2.91 × 104 l mol–1 cm–1) that is slightly soluble in water and can be extracted with isopentyl acetate with an extraction efficiency of 97.4%. The TPP+ GaCl4– complex obtained is useful for the spectrophotometric determination of gallium in the concentration range 0.1–2.2 µg ml–1 in the organic phase, and the method is applicable to the determination of gallium in aluminium.