Comparison of various reversed-phase columns for the simultaneous determination of ephedrines in urine by high-performance liquid chromatography

Different reversed-phase columns for basic analytes were compared for the s imultaneous determination of ephedrines in urine, such as LiChrospher 60 RP -Select B, LiChrospher 100 RP18, Hypersil BDS-C18, Inertsil ODS-2, Spheriso rb ODS-B and Symmetry Shield RP8. Symmetry Shield was the only column which did not require the use of high concentrations of buffer and triethylamine . With this column, a good separation of the six ephedrines and the interna l standard was achieved using 50 mM phosphate buffer-25 mM triethylamine as a mobile phase. Linearity, precision and accuracy were satisfactory for th e levels usually found in urine. Due to these all parameters the developed analytical method was found to be suitable for the application in the dopin g field. (C) 2000 Elsevier Science B.V. All rights reserved.