SEPARATION OF ORGANOPHOSPHONATES BY ION CHROMATOGRAPHY WITH INDIRECT PHOTOMETRIC DETECTION

An ion chromatographic method which utilizes lithium trimesate to sepa rate three diphosphonate drugs and two process related organophosphona tes is described. The lack of a chromophore on the five species and th e high absorptivity of the trimesate anion at 254 nm allows for facile detection using indirect photometry. The effects of mobile phase conc entration on the capacity factor of the species were investigated and a logarithmic relationship was established which was found to be depen dent on the charge of the analyte anion and the mobile phase anion.