High-performance liquid chromatographic determination of the beta(2)-selective adrenergic agonist fenoterol in human plasma after fluorescence derivatization

A sensitive high-performance liquid chromatographic method has been develop ed for the determination of the beta (2)-selective adrenergic agonist fenot erol in human plasma. To improve the sensitivity of the method, fenoterol w as derivatized with N-(chloroformyl)-carbazole prior to HPLC analysis yield ing highly fluorescent derivatives. The assay involves protein precipitatio n with acetonitrile, liquid-liquid-extraction of fenoterol from plasma with isobutanol under alkaline conditions followed by derivatization with N-(ch loroformyl)-carbazole. Reversed-phase liquid chromatographic determination of the fenoterol derivative was performed using a column-switching system c onsisting of a LiChrospher(R) 100 RP 18 and a LiChrospher(R) RP-Select B co lumn with acetonitrile, methanol and water as mobile phase. The limit of qu antitation in human plasma was 376 pg fenoterol/ml. The method was successf ully applied for the assay of fenoterol in patient plasma. (C) 2001 Elsevie r Science B.V. All rights reserved.