Direct determination of plasma copper and zinc in infants by atomic absorption with discrete nebulization.

A new micromethod for the determination of copper and zinc is presented. Sample volumes can be as little as 10 (Cu) and 20 (Zn) microliter of plasma or serum, by using discrete (small sample volume) nebulization in place of conventional nebulization in place of conventional nebulization in atomic absorption spectrometry. The present method has slightly poorer precision than the conventional nebulization method, but has the advantages of requiring commercially available apparatus without any modification, involving simple sample preparation, and being time-saving. Results agree well with those by the trichloroacetic acid deproteinization method. In addition, this method is useful for pediatric samples, and we report reference intervals for full-term and premature infants, as well as adults.