Simultaneous determination of cephalexin and cefadroxil by using the coupling technique of synchronous fluorimetry and H-point standard additions method

The coupling technique of synchronous fluorimetry and the H-point standard additions method was applied to determine cephalexin and cefadroxil with symmetric and seriously overlapping spectra simultaneously. Under the optimum conditions, the linear determination ranges of cephalexin and cefadroxil are ca. 2.5 × 10−4 −7.5 × 10−3 mg ml−1 and ca. 1.0 × 10−4 − 5.0 × 10−3 mg ml−1, respectively. The results showed that cephalexin and cefadroxil can be determined simultaneously when the concentration ratio of cephalexin to cefadroxil vary from 10:1 to 1:5 in the mixed sample. The accuracy and precision of the results are all satisfactory.