A Semiautomated Technique for the Determination of Vitamin C (Ascorbic Acid) in Serum or Plasma Samples,

In nutrition surveys and field studies, large numbers of plasma or serum samples are collected which require measurements for vitamin C ascorbic acid. Under such conditions, it is seldom possible to perform immediate sample analysis. A method for the determination of serum plasma ascorbic acid has been adapted from previously published procedures to meet the needs of such nutrition surveys. The method involves a sample stability preparation on location in the field with the colorimetric quantitation being performed at a later more convenient date employing automated techniques. An evaluation of the procedure indicates that the serum extracts prepared in the field are sufficiently stable approximately 3 loss at two weeks, while frozen unstabilized serum plasma is completely unsatisfactory. The method is reproducible and sensitive and requires only 0.2 ml or less of a serum plasma sample. With proper handling of the samples, the system will rapidly and accurately accommodate large numbers of survey samples requiring vitamin C analysis. Author