Column switching in capillary liquid chromatography–tandem mass spectrometry for the quantitation of pg/ml concentrations of the free basic drug tolterodine and its active 5-hydroxymethyl metabolite in microliter volumes of plasma

• Published in: JOURNAL OF CHROMATOGRAPHY A Vol. 828; no. 1; pp. 209 - 218
• Main Authors: Swart, R, Koivisto, P, Markides, K.E
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Amsterdam Elsevier B.V 18.12.1998; Elsevier
• Subjects: Analysis; Analytical chemistry; Analytisk kemi; Benzhydryl Compounds - blood; Biological and medical sciences; Chemistry; Chromatography, Liquid - instrumentation; Chromatography, Liquid - methods; Cresols - blood; General pharmacology; Humans; Kemi; Mass Spectrometry - methods; Medical sciences; Muscarinic Antagonists - blood; NATURAL SCIENCES; NATURVETENSKAP; Pharmacology. Drug treatments; Phenylpropanolamine; Reproducibility of Results; Tolterodine; Tolterodine Tartrate; Tolterodine; Column switching; Ultrafiltration; Capillary column; Solid phase extraction; Biological fluid; Chemical analysis; On line; Metabolite; HPLC chromatography; Aminophenols; Electrospray; Blood; Chemical enrichment; Blood plasma; Rapid technique; Sample preparation; Antagonist; Quantitative analysis; Trace analysis; Human; Coupled method; Benzene derivatives; Microassay; Reversed phase chromatography; Mass spectrometry MS/MS; Muscarinic receptor; tolterodine; SAMPLES; ultrafiltration; column switching; URINE
• ISSN: 0021-9673
• DOI: 10.1016/S0021-9673(98)00788-2

A capillary column switching system was developed for the determination of low, unbound concentrations of the basic drug tolterodine and its active 5-hydroxymethyl (5-HM) metabolite in human plasma. Free concentrations of tolterodine and 5-HM at p M and n M (pg/ml and ng/ml) levels were obtained by ultrafiltration of 40–400 μl plasma at 37°C. The free fraction (%) was independent of the plasma concentrations of the analytes. Detection of the analytes was performed by sheathless electrospray tandem mass spectrometry in the multiple-reaction monitoring mode. The selectivity of the mass spectrometric detection and the additional clean-up on the pre-column allowed direct injection of the ultrafiltrated plasma samples. Tolterodine and 5-HM were pre-concentrated on a reversed-phase capillary pre-column (1 cm×200 μm) and subsequently backflushed onto the separation column (25 cm×200 μm). The stability of the chromatographic system was good; a large number of ultrafiltrated plasma samples could be injected and the relative standard deviation of the retention times was typically ≤1% (within-day). The accuracy was between 86 and 105% and the precision was between 1 and 7% without the use of an internal standard. Linear calibration curves were obtained between 100 p M and 100 n M.