Fluorescence and terbium-sensitised luminescence determination of garenoxacin in human urine and serum

Fluorescence and terbium-sensitised luminescence properties of new quinolone garenoxacin have been studied. The fluorimetric method allows the determination of 0.060–0.600 μg ml−1 of garenoxacin in aqueous solution containing HCl/KCl buffer (pH 1.5) with λexc=282 nm and λem=421 nm. Micellar-enhanced fluorescence was also studied, leading to a higher than 400% increase in analytical signal in presence of 12 mM sodium dodecyl sulphate (SDS), allowing the determination of 0.020–0.750 μg ml−1 of garenoxacin. The terbium-sensitised luminescence method allows the determination of 0.100–1.500 μg ml−1 of garenoxacin in 12 mM SDS solution containing 0.08 M acetic acid/sodium acetate buffer (pH 4.1) and 7.5 mM Na2SO3 (chemical deoxygenation agent), with λexc=281 nm and λem=546 nm. Relative standard deviation (R.S.D.) values for the three methods were in the range 1.0–2.0%. The proposed procedures have been applied to the determination of garenoxacin in spiked human urine and serum.