Detection and elimination of contaminations interfering with the determination of zinc in plasma.

We undertook detailed examination of the practices and procedures involved in the analysis of serum for zinc by atomic absorption spectrophotometry, to identify possible sources of zinc contamination. Some degree of contamination was found in almost all steps of the procedure. These findings are presented and alternative materials and procedures are described that significantly decrease or eliminate contamination from extraneous zinc. The plasma of 76 normal adults was analyzed by the revised procedure, and a lower mean value was obtained than has been previously reported.