An extraction-free spectrophotometric method for the determination of cationic surfactants, such as cetylpyridinium chloride, cetyltrimethylammonium bromide and zephiramine is proposed, which is based on the formation...An extraction-free spectrophotometric method for the determination of cationic surfactants, such as cetylpyridinium chloride, cetyltrimethylammonium bromide and zephiramine is proposed, which is based on the formation of ternary complexes with Fe(Ⅲ) and chrome azurol S. The molar ratio of the complex is 2:1:1 (Fe(Ⅲ):chrome azurol S:cationic surfactant). The method is simple, rapid and sensitive, giving an apparent molar absorptivity of 4.5×104 L.mol-1.cm-1 and a linear range of 0.1-6.0 umol/L cationic surfactants. The total cationic surfactant content can be determined directly in aqueous solutions by measuring the absorbance at 680 nm (pH 5.8). The method has been successfully applied to water samples.展开更多
基金Project supported by the National Natural Science Foundation of China.
文摘An extraction-free spectrophotometric method for the determination of cationic surfactants, such as cetylpyridinium chloride, cetyltrimethylammonium bromide and zephiramine is proposed, which is based on the formation of ternary complexes with Fe(Ⅲ) and chrome azurol S. The molar ratio of the complex is 2:1:1 (Fe(Ⅲ):chrome azurol S:cationic surfactant). The method is simple, rapid and sensitive, giving an apparent molar absorptivity of 4.5×104 L.mol-1.cm-1 and a linear range of 0.1-6.0 umol/L cationic surfactants. The total cationic surfactant content can be determined directly in aqueous solutions by measuring the absorbance at 680 nm (pH 5.8). The method has been successfully applied to water samples.
