spectrofluorimetric determination of cefixime using terbium-danofloxacin probe

objective(s):cefixime (cfx), is a semi-synthetic third-generation oral cephalosporin antibiotic that is prescribed for the treatment of susceptible infections. there are some procedures for the determination of cfx in pharmaceutical formulations and biological samples. herein a spectrofluorimetric method was proposed for cfx determination based on the fluorescence quenching of terbium-danofloxacin (tb3+-dano) in the presence of cfx. materials and methods: cfx was detected based on fluorescence quenching of terbium-danofloxacin (tb3+-dano) in the presence of cfx with maximum excitation and emission wavelengths at 347 nm and 545 nm, respectively. the quenched fluorescence intensity of tb3+- dano system is proportional to the concentration of cfx. the optimum conditions for the determination of cfx were studied. results: the maximum response was achieved under optimum conditions of [tris buffer]= 0.008 mol/l (ph 6.5), [tb3+]=1×10-4 mol/l  and [dano]=1×10-4 mol/l. the developed method was evaluated in terms of accuracy, precision and limit of detection. the linear concentration ranges for quantification of cfx were 8.8×10-8-8.8×10-7 mol/l and 1.1×10-7-8.8×10-7 mol/l in standard and human serum samples with the detection limits (s/n=3) of 2.8×10-8 mol/l and 3.9×10-8 mol/l, respectively. the cfx was determined in pharmaceutical tablets and spiked serum samples and the results were satisfactory.   conclusion: this method is simple, practical and relatively interference-free for determination of cfx in pharmaceutical tablets and serum samples.