Lanthanide sensitized chemiluminescence determination of grepafloxacin in tablets and human urine Original Research Article

A flow-injection chemiluminescence (CL) method, based on the luminescent properties of the Ce(IV)–Na2SO3–lanthanide(III)–grepafloxacin system, was developed for the determination of grepafloxacin {1-cyclopropyl-6-fluoro-1,4-dihydro-5-methyl-7-(3-methyl-1-piperazinyl)-4-oxo-3-quinolinecarboxylic acid}. La(III), Tb(III), and Eu(III) ions were tested as possible chemiluminescence sensitizers. The best results were achieved when Tb(III) was used as lanthanide ion, so the technique was optimised working with this ion. Under the optimum experimental conditions, the linear range was 0.05–2.00 μg ml−1 grepafloxacin, with a 0.01 μg ml−1 detection limit and 2.0% relative standard deviation (n=10). The proposed procedure has been applied to the determination of grepafloxacin in tablets and spiked human urine.