Determination of phosphorus by graphite furnace atomic absorption spectrometry. Part 3. Analysis of biological reference materials

Abstract

Palladium nitrate mixed with calcium nitrate was found to be the best modifier for the determination of phosphorus in plant and animal tissue samples. The analytical graph is linear only up to 0.06 A s and the analyte addition technique is therefore impractical. The results were calculated from a linear regression equation established using matrix-free references over a limited concentration range after the absence of interferences has been verified. For some samples with high iron content Zeeman-effect background correction was required. Characteristic masses of 3 and 5 ng were found for continuum-source and Zeeman-effect background correction, respectively. The detection limit, however, was better with Zeeman-effect (5 ng) than with continuum-source background correction (8 ng).