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William C Irwin

Publications and source records attributed to William C Irwin.

2 recordsLinked to original sources
PubMed2005

Interference of ascorbic acid with chemical analytes.

BACKGROUND: Ascorbic acid can interfere with methodologies involving redox reactions, while comprehensive studies on main chemistry analysers have not been reported. We therefore attempted to determine the interference of ascorbic acid with analytes on the Beckman Synchron LX20. METHODS: Various concentrations of ascorbic acid were added to serum, and the serum analytes were measured on the LX20. RESULTS: With a serum ascorbic acid concentration of 12.0 mmol/L, the values for sodium, potassium, calcium and creatinine increased by 43%, 58%, 103% and 26%, respectively (P<0.01). With a serum ascorbic acid concentration of 12.0 mmol/L, the values for chloride, total bilirubin and uric acid decreased by 33%, 62% and 83%, respectively (P<0.01), and were undetectable for total cholesterol, triglyceride, ammonia and lactate. There was no definite influence of ascorbic acid on analytical values for total CO(2), urea, glucose, phosphate, total protein, albumin, amylase, creatine kinase, creatine kinase-MB, aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, total iron, unbound iron-binding capacity or magnesium. CONCLUSIONS: Ascorbic acid causes a false increase in sodium, potassium, calcium and creatinine results and a false decrease in chloride, total bilirubin, uric acid, total cholesterol, triglyceride, ammonia and lactate results.

Ascorbic Acid↗
PubMed2005

Vitamin C and aberrant electrolyte results.

Vitamin C interferes with assays involving the redox-reaction. However, the interference of Vitamin C with electrolytes has not been reported. In the present case, we describe a 61-year-old lady with severe electrolyte abnormalities after administration of high doses of vitamin C. This patient, who had terminal colon cancer, presented to hospital with anuria. Her electrolytes were extremely abnormal (determined on the Beckman Synchron LX20): serum sodium 200 mmol/L, potassium 7.0 mmol/L, and chloride 50 mmol/L. Repeated measurements showed similar abnormalities. However, these critical abnormalities did not fit her clinical picture, as she was alert with normal vital signs. One of the specimens was also run on both the ABL700 and the Bayer644 analyzers, and the electrolytes appeared normal. Pooled serum from healthy individuals to which various amounts of vitamin C was added then was analyzed on Beckman Synchron LX20 for electrolytes, demonstrating the interference of vitamin C consistent with the initial finding. Thus, we eventually figured out that the aberrant results were due to the vitamin C caused analytical interference.

Ascorbic Acid↗