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11:56
A Rapid and Specific Microplate Assay for the Determination of Intra- and Extracellular Ascorbate in Cultured Cells
Published on: April 11, 2014
Stability of whole blood and plasma ascorbic acid
A Karlsen1, R Blomhoff, T E Gundersen
1Institute of Basic Medical Sciences, Department of Nutrition, University of Oslo, Oslo, Norway.
European Journal of Clinical Nutrition
|February 15, 2007
Summary
To ensure accurate vitamin C (ascorbic acid) measurements, use heparin blood collection tubes. Proper sample handling, including immediate processing and storage at -70°C, is crucial for vitamin C stability.
Area of Science:
- Biochemistry
- Clinical Chemistry
- Analytical Chemistry
Background:
- Ascorbic acid (AA), the primary form of vitamin C, is vital for numerous physiological processes.
- Accurate measurement of AA in biological samples is essential for clinical diagnostics and research.
- Pre-analytical variables significantly impact the stability and accurate quantification of analytes.
Purpose of the Study:
- To investigate the influence of pre-analytical factors on the short and long-term stability of ascorbic acid in whole blood and plasma.
- To identify optimal conditions for sample collection, handling, and storage to ensure reliable AA measurements.
Main Methods:
- Evaluation of various anticoagulants (heparin, EDTA, citrate, Stabilyte) and their effect on AA levels.
- Assessment of the impact of sample pH (acidification) and storage temperature on AA stability.
- Utilized a sensitive High-Performance Liquid Chromatography (HPLC) method for precise AA quantification.
Main Results:
- Heparin plasma yielded significantly higher baseline AA values compared to EDTA, citrate, Stabilyte plasma, and serum.
- Both pH and storage temperature were identified as critical factors affecting AA stability across different time points.
- AA levels were found to be highly dependent on controlled pre-analytical sample handling conditions.
Conclusions:
- Heparin tubes are recommended for blood collection to preserve AA integrity.
- Immediate centrifugation and plasma acidification post-collection are necessary to prevent rapid AA degradation.
- For long-term stability, samples should be stored at -70°C and analyzed within 80 days to ensure accurate vitamin C status assessment.
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