Effect of evaporation from sample cups on urea nitrogen assay.
The effects of evaporation from sample cups for urea nitrogen assays were determined. Thirty replicate analyses were performed on each of five groups of pooled human serum subjected to controlled evaporation in our laboratory. We found a mean increase in urea nitrogen concentration of one percent per hour due to evaporation. We urge laboratory personnel to take the action necessary to minimize errors due to evaporation. Specimens should always be capped while awaiting analysis in the laboratory.
D001806:Blood Urea Nitrogen; D006801:Humans; D013048:Specimen Handling