Determination of amikacin by Rayleigh scattering method based on the covalent bonding of the analyte with a water soluble polymer

Abstract

A method for the determination of aminoglycoside antibiotics based on the covalent bonding of the analyte with a water-soluble polymer by the Rayleigh scattering method (λex = λem) is proposed. Determination of amikacin (as a model analyte) is carried out by the carbodiimide crosslinking technique, which forms amide bonds between the copolymer of 4-styrenesulfonic acid and maleic acid and the primary amine groups of amikacin. The conditions of the reaction are selected to obtain maximum scattering intensity of the product: reaction time 15 min, pH 7.0, ionic strength 0.02, and measuring of scattering intensity at 362 nm. The determination of amikacin is not influenced by the following (mol/mol ratios): Al(III), Co(II), Cu(II), Fe(III), Ni(II), Zn(II)—300; Cl– and NO3-—250; Ca(II) and Mg(II)—50; HCO3-—20; it is affected by nitrogen compounds at 20–50-fold ratios and proteins at a 2.5-fold ratio. The calibration plot is constructed over the range of 0.2–35 mg/L (r = 0.993); LOD (3s-criterium) is 0.08 mg/L (n = 10, P = 0.95). Analyses are performed on drug powder for injection and gel.