Boernsen, K. Olaf, Floeckher, J M and Bruin, Gerardus (2000) Use of a microplate scintillation counter as a radioactivity detector for miniaturized separation techniques in drug metabolism. Analytical chemistry, 72 (16). pp. 3956-3959. ISSN 0003-2700

Abstract

In miniaturized separation techniques, such as capillary electrophoresis (CE) or capillary liquid chromatography (LC), conventional on-line radioactivity detection of labeled compounds is restricted, because of insufficient sensitivity. It will be shown that a microplate scintillation counter for 96-well plates (TopCount) can be used as a sensitive and easy-to-handle radioactivity detector for capillary LC and CE. The attractive combination of capillary LC, eluent fractionation, and subsequent off-line counting is described. The new method is applied for rapid and sensitive separation and detection of 3H-labeled parent drug and its metabolites at levels between 25 and 700 cpm in rat urine. The advantages of capillary LC coupled to the TopCount, and combined with LC-MS data, can be of benefit in many analytical areas, including the characterization of metabolites at low concentration within complex biological fluids. With the same setup, the fractionation with subsequent off-line counting is equally applicable to CE. This is demonstrated with electrophoretically separated 14C-labeled impurities, nicely resolved from a negatively charged main compound, at low levels.

Item Type:	Article
Date Deposited:	31 Jan 2012 00:45
Last Modified:	01 Feb 2013 00:45
URI:	https://oak.novartis.com/id/eprint/6474