A comparison of β-blockers separation on C18 and new generation C28 columns in human plasma

Abstract

A comparative study of the separation and identification of nine β-blockers in human plasma is presented on C₁₈ and new generation C₂₈ columns. The reported β-blockers are acebutalol, metoprolol, bopindolol, oxprenolol, bufuralol, bisoprolol, indinolol, carazolol and alprenolol. The mobile phase used was phosphate buffer (20.0 mM, pH 7.0)–acetonitrile (75 : 25, v/v) at 0.5 mL min⁻¹ flow rate. The detection was achieved at 220 nm with a working temperature of 27 ± 1 °C. The values of the retention, separation and resolution factors on the C₁₈ column varied from 2.38–14.68, 1.32–1.51, and 1.49–4.91, respectively. On the other hand, these values were 2.04–11.85, 1.23–1.37 and 1.33–6.03 on the C₂₈ column, respectively. The new generation C₂₈ column was found to be better than C₁₈ due to the highly non-polar nature of the former. Attempts have been made to explain the separation mechanism of these columns. The SPE method was selective, efficient, fast and reproducible. The reported β-blockers were found to interact with plasma proteins. The reported SPE and HPLC methods are selective, efficient, rugged, fast and reproducible.