[Fluorimetric study of methacycline complex formation with beryllium, aluminum, magnesium, calcium and zinc ions]

Complex formation of metacycline (Pv) with beryllium, aluminium, magnesium, calcium and zinc ions in aqueous solutions was studied fluorometrically. The antibiotic formed the following compounds: CaPv2 (pH 9.45), MgPv (pH 10.40), Be Pv (pH 7.0 and 11), Ca Pv (pH 13.5), Zn Pv (pH 7.15) and Al Pv (pH 6.0). Relationship between the solution fluorescence level and the values of pH, the quantum yield of fluorescence of Pv and the complexes and the kinetics of the reactions of complex formation of Pv with Be and Al were studied. The mechanism of Pv complex formation with the metal ions is discussed. A method for analysis of microgram amounts of Pv in biological fluids was developed. The method is based on the antibiotic fluorescent reaction with magnesium ions.