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United States Department of Agriculture

Agricultural Research Service

Research Project: VITAMIN K AND VITAMIN K-DEPENDENT PROTEIN DURING AGING

Location: Human Nutrition Research Center on Aging

Title: Measurement of Menadione in urine by HPLC

Authors
item Al Rajabi, Ala -
item Peterson, James -
item Choi, Sang Woon -
item Suttie, John -
item Barakat, Susan -
item Booth, Susan -

Submitted to: Journal of Chromatography B
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: July 20, 2010
Publication Date: September 15, 2010
Citation: Al Rajabi, A., Peterson, J., Choi, S., Suttie, J., Barakat, S., Booth, S.L. 2010. Measurement of Menadione in urine by HPLC. Journal of Chromatography B. 878(26):2457-2460.

Interpretive Summary: Menadione may be an important metabolite of vitamin K that is excreted in urine. A high performance liquid chromatography (HPLC) method with fluorescence detection was developed to measure menadione in urine. A different form of vitamin K, menaquinone-2 (MK-2), was used as an internal standard to correct for any losses incurred during the analysis. Menadione circulates in urine in a conjugated form so sample preparation involved hydrolysis of the conjugates to release the menadione. Sensitivity of the assay was increased by reducing water present in the solvents used with the HPLC. Using this assay, the increase in urinary menadione was measured in response to three years of phylloquinone supplementation among older adults. This HPLC method presents a sensitive, precise and reproducible way to detect menadione in urine.

Technical Abstract: Menadione may be an important metabolite of vitamin K that is excreted in urine. A high performance liquid chromatography (HPLC) method with a C30 column, fluorescence detection and post-column zinc reduction was developed to measure menadione in urine. The mobile phase was composed of 95% methanol with 0.55% aqueous solution (2 M zinc chloride, 1 M acetic acid, and 1 M sodium acetate) and 5% DI H2O. Menaquinone-2 (MK-2) was used as an internal standard. The standard calibration curve was linear with a correlation coefficient (R2) of 0.999 for both menadione and MK-2. The detection limit was determined to be 0.05 pmole menadione/ injection. Sample preparation involved hydrolysis of menadiol conjugates and oxidizing the released menadiol to menadione. Sensitivity of the assay was increased through incomplete evaporation and reduction of H20 in the mobile phase. Using this assay, the increase in urinary menadione was measured in response to 3 years of phylloquinone supplementation among older adults. This HPLC method presents a sensitive, precise and reproducible way to detect menadione in urine.

Last Modified: 10/1/2014
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