title: Assay of omeprazole and omeprazole sulfone by semi-microcolumn liquid chromatography with mixed-function precolumn.
abstract: A column-switching system based on semi-microcolumns was used for direct analysis of omeprazole and omeprazole sulfone in human plasma samples. Plasma samples were injected into a mixed-function (MF Ph-1) column (35 mmx4.6 mm I.D.) to remove proteins and other non-specific peak producing substances from the analyte-containing time zone. The analyte-containing fraction was thereafter transferred to a C-18 semi-microcolumn (250 mmx1.5 mm I.D.) after concentration at the C-18 intermediate column. The absorbance at 302 nm in a ultraviolet (UV) detector was recorded to measure the concentration. The detection limit for omeprazole and omeprazole sulfone in the present method was 10 ng/ml. Interbatch variation (coefficient of variation) of the QC samples spanned less than 10% and intra-batch variation less than 2%. The recovery ratios of omeprazole and omeprazole sulfone were over 98%. The current method can be used as a simpler procedure with similar sensitivity and reproducibility as previously reported methods.
authors.affiliation: Department of Pharmacology, Ghil Hospital Emergency Center, Gachon Medical School, Inchon, South Korea. yimds@gachon.ac.kr
authors.forename: D S
authors.initials: DS
authors.lastname: Yim
authors.forename: J E
authors.initials: JE
authors.lastname: Jeong
authors.forename: J Y
authors.initials: JY
authors.lastname: Park
mesh_terms: D000897:Anti-Ulcer Agents / Q000097:blood; D002138:Calibration; D002853:Chromatography, Liquid / Q000379:methods*; D006801:Humans; D009853:Omeprazole / Q000031:analogs & derivatives / Q000097:blood* / Q000378:metabolism; D011786:Quality Control; D015203:Reproducibility of Results
chemical_list: D000897:Anti-Ulcer Agents; C040450:omeprazole sulfone; D009853:Omeprazole