Analysis of supplemented vitamin K1(20) in serum microsamples by solid-phase extraction and narrow-bone HPLC with multichannel ultraviolet detection.
A sensitive method for the determination of vitamin K1(20) in serum microsamples (50 microL) has been developed, utilizing solid-phase extraction with C8 Bond-Elut columns and reversed-phase narrow-bore high-performance liquid chromatography [2.1 mm (i.d.), column] with a nonaqueous eluent. Recovery from serum (49 ng/mL) was 76% (n = 2). Peak homogeneity was assessed by photodiode array detection with absorbance ratio, spectral normalization, and transformation to the first- and second-derivative chromatograms. Calibration data at 248 nm over two ranges (20-200 ng/mL, 200-4000 ng/mL) varied linearly with concentration and were suitable for studies of vitamin K1 supplementation. By comparison with conventional columns, sensitivity was increased twofold.
Pharmaceutical Chemistry, School of Pharmacy, University of Bradford, U.K.
E M
EM
Kirk
A F
AF
Fell
D002851:Chromatography, High Pressure Liquid / Q000295:instrumentation; D006801:Humans; D008832:Microchemistry; D012997:Solvents; D013056:Spectrophotometry, Ultraviolet; D014812:Vitamin K / Q000008:administration & dosage / Q000097:blood*
D012997:Solvents; D014812:Vitamin K