A simple method for plasma total vitamin C analysis suitable for routine clinical laboratory use. Issue 1 (December 2015)

• Record Type: Journal Article
• Authors: Robitaille, Line; Hoffer, L.
• Is Part Of: Nutrition journal. Volume 15:Issue 1(2016)
• Page Start: 1
• Page End: 9
• Publication Date: 2015-12
• Subjects: Ascorbic acid -- Ascorbic acid deficiency -- Avitaminosis -- Dehydroascorbic acid -- Malnutrition -- Vitamin C; Nutrition -- Periodicals; 612.305
• DOI: 10.1186/s12937-016-0158-9
• Languages: English
• ISSNs: 1475-2891

Abstract

Abstract Background In-hospital hypovitaminosis C is highly prevalent but almost completely unrecognized. Medical awareness of this potentially important disorder is hindered by the inability of most hospital laboratories to determine plasma vitamin C concentrations. The availability of a simple, reliable method for analyzing plasma vitamin C could increase opportunities for routine plasma vitamin C analysis in clinical medicine. Methods Plasma vitamin C can be analyzed by high performance liquid chromatography (HPLC) with electrochemical (EC) or ultraviolet (UV) light detection. We modified existing UV-HPLC methods for plasma total vitamin C analysis (the sum of ascorbic and dehydroascorbic acid) to develop a simple, constant-low-pH sample reduction procedure followed by isocratic reverse-phase HPLC separation using a purely aqueous low-pH non-buffered mobile phase. Although EC-HPLC is widely recommended over UV-HPLC for plasma total vitamin C analysis, the two methods have never been directly compared. We formally compared the simplified UV-HPLC method with EC-HPLC in 80 consecutive clinical samples. Results The simplified UV-HPLC method was less expensive, easier to set up, required fewer reagents and no pH adjustments, and demonstrated greater sample stability than many existing methods for plasma vitamin C analysis. When compared with the gold-standard EC-HPLC method in 80 consecutive clinical samples exhibiting a wide range of plasma vitamin C concentrations, it performed equivalently. Conclusion The easy set up, simplicity and sensitivity of the plasma vitamin C analysis method described here could make it practical in a normally equipped hospital laboratory. Unlike any prior UV-HPLC method for plasma total vitamin C analysis, it was rigorously compared with the gold-standard EC-HPLC method and performed equivalently. Adoption of this method could increase the availability of plasma vitamin C analysis in clinical medicine.