Study On The New Methods For The Determination Of Tetracycline Antibiotics By Resonance Rayleigh Scattering

In recent ten years, resonance Rayleigh scattering (RRS) technique has attracted more and more attention because of its high sensitivity, simplicity and good selectivity. It has been extensively and successfully unitized to study and determination of biological macromolecules, trace metal ions, nonmetal ions and nanoparticle probe et al. But it is rarely applied in pharmaceutical field. Therefore, we investigated the interaction between tetracycline antibiotics (TCs), metal ions and dyes by RRS method. Besides, the spectral characteristics, the affecting factors and the properties of analytical chemistry, the reaction mechanism and their analytical applications have been studied. 1 TCs-U(â…¥)-Triphenylmethane dyes systemsIn pH 5.1-6.0 acetic acid-sodium acetate buffer medium, tetracycline antibiotics such as doxycycline (DOTC), chlortetracycline (CTC), oxytetracycline (OTC), and tetracycline (TC) react with UO₂²⁺ to form 1:1 cation chelates. It results in the change of the absorption spectra of TCs, but the resonance Rayleigh scattering (RRS) intensities are not increased. When the cation chelates further react with Triphenylmethane dyes such as water blue (WB), lissamine green (LG) and fast green FCF (FG) to form the ternary ion-association complexes, the great enhancement of RRS intensity and new RRS spectra are observed. The detection limits are between 28.5 ng/ml and 84.4 ng/ml depending on different TCs. The spectral characteristics, the optimum conditions of the reactions, affecting factors and the properties of analytical chemistry and their analytical applications have been studied. Besides, the reaction mechanism is discussed. It can be applied to the determination of DOTC in troche, feedstuff and human urine sample.