title: Sensitive high-performance liquid chromatographic determination of ionic drugs in biological fluids with short-wavelength ultraviolet detection using column switching combined with ion-pair chromatography: application to basic compounds.
abstract: A highly sensitive and selective high-performance liquid chromatographic method with short-wavelength UV detection is described for the determination of ionic compounds in biological fluids, which was applied to two basic compounds, 2-(3-[4-(4-fluorophenyl)-1-piperazinyl]propyl)-6,7,8,9-tetrahydro-2H-nap htho [2,3-b][1,4]oxazin-3(4H)-one (I) and methyl 2-(4-diphenylmethyl-1-piperazinyl)ethyl (+/-)-1,4-dihydro-2,6-dimethyl-4-(m-nitrophenyl)-3,5-pyridinedicarboxyla te (II), in human serum. The method is based on the combination of the column-switching technique and ion-pair chromatography. In the first ODS column, the analyte is pre-separated from endogenous substances in serum by ion-pair chromatography. After column switching, in the second ODS column the heart-cut fraction containing the analyte is further separated by non-ion-pair chromatography from coeluted endogenous substances from the first ODS column. The proposed method offered high sensitivity and selectivity with UV detection at 215 nm for I and 230 nm for II. The detection limits were 0.2 ng/ml for both I and II using 1 ml of serum. The principle of the proposed method would be applicable to both acidic and basic compounds in biological fluids with a suitable ion-pair reagent.
authors.affiliation: Analytical Laboratories, Takeda Chemical Industries, Ltd., Osaka, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Yamashita
authors.forename: M
authors.initials: M
authors.lastname: Motohashi
authors.forename: T
authors.initials: T
authors.lastname: Yashiki
mesh_terms: D002851:Chromatography, High Pressure Liquid; D006801:Humans; D007202:Indicators and Reagents; D004364:Pharmaceutical Preparations / Q000032:analysis* / Q000097:blood / Q000652:urine; D013056:Spectrophotometry, Ultraviolet
chemical_list: D007202:Indicators and Reagents; D004364:Pharmaceutical Preparations