Determination of gold in plasma and plasma fractions by atomic absorption spectrometry and by neutron activation analysis.

Three techniques of gold analysis, flame and electrothermal atomic absorption spectrometry and neutron activation analysis, have been compared, using plasma and plasma fractions (derived by gel chromatography) from rheumatoid patients receiving aurothiomalate therapy and from plasma samples incubated with aurothiomalate in vitro. The three methods correlated well in the analysis of gold in whole plasma, but only neutron activation analysis was suitable for the assay of all the plasma fractions. The susceptibility of the two atomic absorption methods to interference by sodium chloride was investigated.