Determination of fosfomycin by indirect spectrophotometric method

2-(5-Bromo-2-pyridylazo)-5-diethylaminophenol (5-Br-PADAP) is a sensitive p hotometric reagent for determination of zirconium, when fosfomycin is added , it can quantitatively replace 5-Br-PADAP by complexing with zirconium, th us, an indirect spectrophotometric method based on ligand exchange has been established. The detection wavelength is at 605 nm, and the apparent molar absorption coefficient was found to be 4.59 x 10(4) l mol(-1) cm(-1). Beer 's law is obeyed in the range of 0-28 x 10(-6) M. The composition and stabi lity constant of zirconium with 5-Br-PADAP and with fosfomycin has also bee n estimated. The proposed method is simple and reproducible, it was applica ble to the analysis of fosfomycin from pharmaceutical manufacture. (C) 1999 Elsevier Science B.V. All rights reserved.