In this study, the suitability of basic mobile phases in combination with the XTerra or the XBridge stationary phase was investigated. A mobile phase consisting of water, 0.1 M ammonium carbonate pH 8.5 and methanol, was used as it gave enhanced MS signal. The XBridge column gave an overall better chromatographic separation and proved to be stable over a long period of use. Therefore, this column was selected for further investigation. A gradient elution was needed to elute all analytes within reasonable time. A good separation of the analytes was achieved;