Analyzing mixtures of amino acids and carbohydrates using bi-modal integrated amperometric detection

Described in this work is a new detection methodology - bi-modal integrated amperometric detection - for identifying peaks and as a tool for solving d ifficult separation problems. Bi-modal integrated amperometry makes it poss ible to selectively detect amino acids, amino sugars, and carbohydrates fol lowing their separation by anion-exchange. Selectivity is gained by two dif ferent methods of integrating anodic current on an otherwise identical wave form. As with the single-mode integrated amperometry reported previously, t he limits of detection are in the femtomole range and linear calibration pl ots are possible over three orders of magnitude. This new detection method does not require analyte derivatization. The practical utility of this new technique is demonstrated in the analysis of amino acids and sugars in a re combinant mammalian cell culture medium. (C) 1999 Elsevier Science B.V. All rights reserved.