Trace metal determinations in blood obtained in evacuated collection tubes

Abstract

Using atomic absorption spectrophotometry, we determined levels of iron, copper and zinc in serum or plasma samples collected in acid-washed containers and in commercially available evacuated tubes including one model equipped with rubber stoppers prepared by a process which reduces zinc contamination of the rubber. Serum or plasma from all evacuated tubes yielded iron and copper values which were comparable to those from serum obtained in acid-washed glass. Zinc values were higher from all evacuated tubes than from acid-washed glassware. Values obtained from samples collected in the specially-prepared tubes were 10% higher than values obtained from samples collected in acid-washed glassware. Thus, the specially-prepared evacuated tubes may only be useful in large-scale clinical screening studies. Traditional blood collection methods for zinc determination should be used when accuracy is required.