Peter Neubert

Automation der Lösungsmittelextraktion von Arzneiwirkstoffen im kontinuierlichen Durchfluß

SummaryThe performance of liquid/liquid extractions in continuous flow-systems is described by means of two different fluorescent compounds.The conventional AutoAnalyzer-System (using air-segmentation) is compared with the Flow Injection Analysis (FIA)-method. The extractability of compounds from biological fluids is evaluated with regard to sampling rate, solvent and reagent requirements and to recovery depending on the kind of extraction used and on the protein content of the sample.An automated system for the extraction of drugs from serum and urine is described. It is intended to be a part of a fully automated system for sample preparation (extraction, change of solvent) for chromatographic analysis.ZusammenfassungDie Durchführung von Flüssig/ Flüssig-Extraktionen im kontinuierlichen Durchfluß wird am Beispiel zweier fluorescierender Substanzen untersucht. Das herkömmliche AutoAnalyzer-Verfahren (mit Luftsegmentierung) wird mit der Flow-Injection Analysis (FIA)-Methodik verglichen. Die Extrahierbarkeit der Substanzen aus biologischen Flüssigkeiten wird im Hinblick auf Probenfrequenz, Reagens- und Lösungsmittelverbrauch und Wiederfindung in Abhängigkeit von der Methode und vom Proteingehalt der Proben beurteilt.Es wird ein automatisches Analysensystem zur Extraktion von Wirkstoffen aus Serum und Urin beschrieben. Es kann als Bestandteil eines Gerätes für die vollständige Automation der Probenaufarbeitung (Extraktion, Lösungsmittelwechsel) für chromatographische Analysen angesehen werden.

Automated pre-column high-performance liquid chromatographic method for the investigation of adibendan metabolism

An automated pre-column high-performance liquid chromatographic method has been developed for the isolation of adibendan and metabolites from biological fluids and for their simultaneous quantitative assay. High sensitivities were obtained by the use of a multiple-injection device allowing solid-phase extraction from several successive sample injections with enrichment of metabolite traces on the pre-column. Two metabolites in dog urine were identified as N-oxypyridine (M1) and 2-hydroxypyridine (M2) derivatives of adibendan, while the structure of M3 is still unknown. M1 and M2 are also metabolites in rats, rabbits and humans, and contribute to cardiovascular efficacy. The metabolic profiles were determined in plasma, urine and bile, as a function of dose, route of administration and sex, using radioactivity and ultraviolet detection of the eluates.