Automated high-performance liquid chromatographic and column-switching technique for on-line clean-up and analysis of diltiazem in human plasma.
An automated high-performance liquid chromatographic method for the direct injection of diltiazem plasma samples has been developed. It involves automatic injection of plasma samples (200 microliter) on a C18 pre-column (40 micron), clean-up of the pre-column with water to remove proteins and salts and transfer of the analytes to the analytical column. During the chromatographic process, the pre-column is reset with respect to the analytical column and flushed with different solvents to remove endogenous contaminants. The analysis is performed on a C18 column coupled to an ultraviolet detector. The whole process (on-line clean-up and chromatography) takes ca. 12 min and is completely automated. The detection limit of the method is ca. 2 ng/ml with 200-microliter aliquots of plasma sample. Very good results were obtained for the day-to-day and within-day reproducibilities (5.9 and 4.3%, respectively, in the concentration range 10-200 ng/ml in plasma).
Pharmacokinetic Laboratory, L.E.R.S.-Synthelabo, Limito-Milano, Italy.
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Ascalone
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Dal Bo'
D000284:Administration, Oral; D001322:Autoanalysis; D002851:Chromatography, High Pressure Liquid; D004110:Diltiazem / Q000097:blood*; D006801:Humans; D008297:Male; D013056:Spectrophotometry, Ultraviolet
D004110:Diltiazem