Matrix modification--the use of protein-free solutions in the determination of metals in blood by flame atomic fluorescence and emission spectrometry

A procedure is described for matrix modification in the determination of metals in blood by flame spectrometric methods. The protein is removed by precipitation with dilute nitric acid and centrifugation and the supernatant liquid is used for direct analysis. Nitric acid is compared with other acids as the precipitant. The technique is simple, contamination-free and provides a solution which may be directly compared with aqueous calibration standards. Its application for determination of clinically important metals by flame atomic fluorescence and emission spectrometry is demonstrated.