Berndt H, Jackwerth E
J Clin Chem Clin Biochem. 1979 Jul;17(7):489-94.
By sample application in measured quantities ("injection method") the quality of serum required for the determination of trace elements can be considerably decreased with essentially no loss in sensitivity. The volume of solution, 50 or 100 microliters, required for a single measurement is added to the nebulizer of the AAS apparatus manually with a bulb pipette, or automatically by a suitable sample changing system. A total of 500 microliters serum is sufficient for the determination of traces of Fe, Cu, and Zn. It was shown that under suitable conditions a total volume of 25 microliters serum is sufficient for the determination of Cu and Zn by flame atomic absorption-atomic emission photometry.