Determination of BAY y 3118, a novel 4-quinolone, in biological fluids using high-performance liquid chromatography and photothermal post-column derivatization.
A reversed-phase high-performance liquid chromatographic (HPLC) method that allows the sensitive and selective quantification of a novel 4-quinolone (BAY y 3118, I) in biological fluids is described. After sample dilution with 0.05 M phosphoric acid (plasma) or 0.1 M phosphate buffer pH 7.5 (urine), samples can be directly injected into the HPLC system. Prior to fluorescence detection, I is decomposed to fluorescence compound(s) by post-column derivatization utilizing either photolysis (Beam Boost reaction unit) or a combination of thermolysis and photolysis (laboratory-made post-column reactor). Compared with fluorescence detection alone, derivatization increases the signal intensity (about 80-fold) and the selectivity of the detection significantly. Concentrations down to 0.01 mg/l could be quantified in biological fluids. Only thermolysis was not able to decompose I to fluorescence products. Investigations on the stability of I in plasma and urine demonstrate good stability under the different conditions tested. The method was applied to human plasma and urine samples from a subject after a single oral dose of 100 mg of I.
Schaefer
H G
HG
Pharma Research Center, Bayer AG, Wuppertal, Germany.
D000890:Anti-Infective Agents / Q000032:analysis* / Q000097:blood / Q000652:urine; D002851:Chromatography, High Pressure Liquid; D024841:Fluoroquinolones; D006801:Humans; D007202:Indicators and Reagents; D008297:Male; D010777:Photochemistry; D015363:Quinolones / Q000032:analysis* / Q000097:blood / Q000652:urine; D013050:Spectrometry, Fluorescence
D000890:Anti-Infective Agents; D024841:Fluoroquinolones; D007202:Indicators and Reagents; D015363:Quinolones; C079807:Bay Y3118