A Stabilizing Agent, PCA/DTPA, Improves Plasma Storage Life for the Chromsystems Vitamin C Assay up to Six Months
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The commonly used Chromsystems vitamin C (ascorbate) assay (Munich, Germany) has a sample storage life of five days at –20°C. Stabilizing agents have been successfully used to increase longevity; however, their suitability with this commercial assay is unclear. We investigated the compatibility of a stabilizing agent, perchloric acid/diethylenetriaminepentaacetic acid (PCA/DTPA), with the Chromsystems assay. Plasma was stored at –80°C, with or without PCA/DTPA. Storage up to six months was assessed through baseline and repeat analyses, stability was assessed by comparing paired non-stabilized and PCA/DTPA-stabilized plasma, and performance was assessed using allowable performance specifications of an external quality assurance program. Ascorbate concentration was significantly lower in non-stabilized plasma than in paired PCA/DTPA-stabilized plasma, with a proportional difference of 11% (P=0.01). All storage analysis results were within the allowable performance specifications. Storage at –80°C prevented plasma ascorbate oxidation; however, substantial oxidation occurred during sample processing. In conclusion, PCA/DTPA significantly reduces ascorbate oxidation, and PCA/DTPA-stabilized ascorbate plasma is compatible with the Chromsystems assay and stable for up to six months, when stored at –80°C.
Abstract
The commonly used Chromsystems vitamin C (ascorbate) assay (Munich, Germany) has a sample storage life of five days at –20°C. Stabilizing agents have been successfully used to increase longevity; however, their suitability with this commercial assay is unclear. We investigated the compatibility of a stabilizing agent, perchloric acid/diethylenetriaminepentaacetic acid (PCA/DTPA), with the Chromsystems assay. Plasma was stored at –80°C, with or without PCA/DTPA. Storage up to six months was assessed through baseline and repeat analyses, stability was assessed by comparing paired non-stabilized and PCA/DTPA-stabilized plasma, and performance was assessed using allowable performance specifications of an external quality assurance program. Ascorbate concentration was significantly lower in non-stabilized plasma than in paired PCA/DTPA-stabilized plasma, with a proportional difference of 11% (P=0.01). All storage analysis results were within the allowable performance specifications. Storage at –80°C prevented plasma ascorbate oxidation; however, substantial oxidation occurred during sample processing. In conclusion, PCA/DTPA significantly reduces ascorbate oxidation, and PCA/DTPA-stabilized ascorbate plasma is compatible with the Chromsystems assay and stable for up to six months, when stored at –80°C.
참고문헌 (13)
- Collie JTB, "Vitamin C measurement in critical illness: challenges, methodologies and quality improvements", Clin Chem Lab Med, 58, pp.460~470 (2020)
- "Vitamin C End of Cycle 41 Report"[URL]
- Salminen I, "Plasma ascorbic acid preparation and storage for epidemiological studies using TCA precipitation", Clin Biochem, 41, pp.723~727 (2008)
- Karlsen A, "Stability of whole blood and plasma ascorbic acid", Eur J Clin Nutr, 61, pp.1233~1236 (2007)
- Pullar JM, "Appropriate handling, processing and analysis of blood samples is essential to avoid oxidation of vitamin C to dehydroascorbic acid in clinical samples", Antioxidants, 7, pp.29~ (2018)
- Lykkesfeldt J, "Ascorbate and dehydroascorbic acid as reliable biomarkers of oxidative stress: analytical reproducibility and long-term stability of plasma samples subjected to acidic deproteinization", Cancer Epidemiol Biomarkers Prev, 16, pp.2513~2516 (2007)
- Rossi B, "Setup and validation of a convenient sampling procedure to promptly and effectively stabilize vitamin C in blood and plasma specimens stored at routine temperatures", Anal Bioanal Chem, 408, pp.4723~4731 (2016)
- Jenab M, "Long-term cryoconservation and stability of vitamin C in serum samples of the European prospective investigation into cancer and nutrition", Cancer Epidemiol Biomarkers Prev, 14, pp.1837~1840 (2005)
- Fujii T, "Vitamin C, Hydrocortisone and Thiamine in Patients with Septic Shock (VITAMINS) trial: study protocol and statistical analysis plan", Crit Care Resusc, 21, pp.119~125 (2019)
- Bobrowicz E, "Preanalytical factors in human plasma ascorbate assay", Clin Chim Acta, 314, pp.237~239 (2001)
- Lykkesfeldt J, "Ascorbate and dehydroascorbic acid as biomarkers of oxidative stress: validity of clinical data depends on Vacutainer system used", Nutr Res, 32, pp.66~69 (2012)
- Talwar DK, "Biological variation of vitamins in blood of healthy individuals", Clin Chem, 51, pp.2145~2150 (2005)
- Ching SYL, "Stability of ascorbic acid in serum and plasma prior to analysis", Ann Clin Biochem, 39, pp.518~520 (2002)