A NEW APPROACH TO STUDY BENZODIAZEPINE SEPARATION AND THE DIFFERENCESBETWEEN A METHANOL WATER AND ACETONITRILE/WATER MIXTURE ON COLUMN EFFICIENCY IN LIQUID-CHROMATOGRAPHY/

A chemometric methodology was used to study column efficiency and the separation of 10 benzodiazepines in reversed phase liquid chromatograp hy. New simple mathematical models and the organic modifier (OM) organ ization of ACN in the water, explained differences on column efficienc y observed when ACN is chosen instead of CH3OH. A new response functio n, which takes into account the separation quality and the analysis ti me, was proposed for the separation optimization. The result, a mobile phase ACN/water (60/40)(V/V), with a flow rate = 1.00 mL/min and a co lumn temperature = 47 degrees C were optimum values for a rapid chroma tographic separation.