Determination of kanamycin in serum by solid-phase extraction, pre-capillary derivatization and capillary electrophoresis.
An effective method based on solid-phase extraction (SPE) and capillary electrophoresis (CE) for the determination of kanamycin in human serum was developed and validated. Off-line SPE was employed for the isolation of kanamycin from serum on a carboxypropyl-bonded phase (CBA) weak cation-exchange cartridge. A mixture of 0.2 M borate (pH 10.5)-methanol (50:50, v/v) was used as analyte eluting solvent. After pre-capillary derivatization with o-phthalaldehyde/mercaptoacetic acid reagent, the sample was analyzed by CE with a separation buffer of 30 mM borax, pH 10.0, containing 16% (v/v) methanol. A linear response over the concentration range 5-40 microgram/ml was obtained with a detection limit of 2 microgram/ml. Intra-day and inter-day precision were 6.2 and 10.3% RSD, respectively. Recoveries of approximately 90% were found. For the determination of lower levels of kanamycin (<5 microgram/ml), NH(4)OH (25%, w/v)-methanol (30:70, v/v) was used for analyte elution. After evaporation, reconstitution and derivatization, the sample was analyzed by on-line field-amplified sample stacking (FASS) CE. Good linearity in the concentration range 0.4-5 microgram/ml was obtained with a detection limit of 0.1 microgram/ml. Intra-day and inter-day RSD were 3.4 and 11.2%, respectively. Recoveries of approximately 60% were found. The method was successfully applied to the analysis of kanamycin in sera of tuberculosis patients at peak level and trough level concentrations.
Long
Y H
YH
Laboratory for Pharmaceutical Chemistry and Drug Analysis, K.U. Leuven, E. Van Evenstraat 4, B-3000, Leuven, Belgium.
Hernandez
M
M
Kaale
E
E
Van Schepdael
A
A
Roets
E
E
Borrull
F
F
Calull
M
M
Hoogmartens
J
J
D000900:Anti-Bacterial Agents / Q000097:blood*; D002021:Buffers; D002138:Calibration; D019075:Electrophoresis, Capillary / Q000379:methods*; D006863:Hydrogen-Ion Concentration; D007612:Kanamycin / Q000097:blood*; D015203:Reproducibility of Results
D000900:Anti-Bacterial Agents; D002021:Buffers; D007612:Kanamycin