title: Effects of the pre-column in automated on-column injection capillary gas chromatography.
abstract: In this work, we investigated the effects of pre-columns and press-fit connectors on automated cold on-column injection capillary gas chromatography. Verapamil, a calcium channel blocking vasodilator used in the treatment of angina, arrhythmias and hypertension, and norverapamil, an active metabolite, were used as model compounds in these investigations. Wide-bore fused-silica tubing deactivated with OV-1701-vinyl was also studied with respect to its suitability as pre-column material. The detector response of verapamil versus an internal standard was consistent at micrograms/ml and ng/ml levels, while that of norverapamil decreased with the amount injected. However, the decrease in response of norverapamil appeared to be unrelated to the presence of a pre-column or press-fit connector in the chromatographic system.
authors: Department of Medicinal Chemistry and Pharmacognosy, University of Georgia, College of Pharmacy, Athens 30602.
authors: R F
authors: RF
authors: Arrendale
authors: J T
authors: JT
authors: Stewart
authors: R M
authors: RM
authors: Martin
mesh_terms: D002849:Chromatography, Gas / Q000379:methods*; D006801:Humans; D012015:Reference Standards; D014700:Verapamil / Q000031:analogs & derivatives / Q000097:blood
chemical_list: C016904:norverapamil; D014700:Verapamil