Selective kinetic determination of amikacin in serum using long-wavelength fluorimetry.
A simple and rapid method for the determination of the antibiotic amikacin, involving the use of a long-wavelength fluorophor, namely indocyanine green, (ICG) is presented. The dye is oxidised by cerium(IV) in acidic medium, resulting in a sharp decrease of the fluorescence, but this fluorescence quenching is inhibited in the presence of amikacin, which can be ascribed to the formation of an ion pair between the fluorophor and the analyte. The initial rate of the system is monitored at lambda(ex): 765 nm and lambda(em): 812 nm as excitation and emission wavelengths, respectively, using the stopped-flow mixing technique, which makes the method applicable to automatic routine analysis. Each measurement is obtained in only 2-3s. The method presents a detection limit of 0.02 microg m1(-1) in standard solutions, which corresponds to 2.5 microg ml(-1) in serum samples. The precision is in the range 4.8-6%. The good selectivity of the method allows amikacin to be determined in the presence of other antibiotics, including other aminoglycoside antibiotics, in serum. The recoveries obtained from the analysis of different samples were in the range 89.4-104.7%.
Sánchez-Martínez
M L
ML
Department of Analytical Chemistry, Faculty of Sciences, University of Córdoba, Anexo C-3, Campus of Rabanales, E-14071 Córdoba, Spain.
Aguilar-Caballos
M P
MP
Gómez-Hens
A
A
D000583:Amikacin / Q000097:blood* / Q000493:pharmacokinetics*; D005456:Fluorescent Dyes / Q000032:analysis; D005470:Fluorometry / Q000379:methods; D007208:Indocyanine Green / Q000032:analysis
D005456:Fluorescent Dyes; D000583:Amikacin; D007208:Indocyanine Green