LUMINESCENT PROPERTIES OF TERBIUM WITH S- (4-BROMANILIDE) METHYL ETHER OF SULFOSALICYLIC ACID

Abstract

It was of interest to search for luminescent reactions to terbium in complexes with sulfosalicylic acid derivatives and to strengthen them by studying the influence of the third components (aminopolycarboxylic acids, organic bases, and surfactants). Absorption spectra of solutions of rare earth element complexes in the wavelength range of 220-880 nm were recorded using the SF-26 spectrophotometer. To obtain the maximum luminescence of the luminescent reaction of rare earth elements in complexes with organic reagents, a number of factors that have a significant impact on the intensity of solutions of luminescent complexes have been studied. Such factors are the pH of the complexes, concentration of reagent, time of maturation complexes, the irradiation time, the order of adding the reagents and the ionic strength of the solutions. According to studies conducted, surfactants increase the luminosity of terbium ions in complexes with sulfosalicylic acid derivatives. As a surfactant, decylpyridinium chloride was used in solutions. The existence of a bright luminescent green reaction of terbium in a complex with methyl ester S- (4-bromanilide) sulfosalicylic acid was established. The optimal conditions for the complexation of terbium were selected and highly sensitive luminescent methods for determining terbium in various objects were developed. Terbium is converted into a luminescent complex compound with an organic reagent S- (4-bromanililide) sulfosalicylic acid methyl ester in the presence of a cationic surfactant decylpyridinium chloride in a ratio of 1: 2: 13, pH 7.9 ± 0.08. The resulting complex compound of terbium upon irradiation with a mercury lamp under ultraviolet light gives intense green luminescence that is stable during standing and irradiation. As a consequence, the proposed method allows to determine terbium in the oxides of rare earth elements, which are quenchers of luminescence with a sensitivity of 10-8%, bypassing the extraction stage. The sensitivity of the determination of terbium in the oxides of the remaining lanthanides is 2.4·10-10%.