Determination of gold in blood fractions by atomic-absorption spectrometry using carbon rod and carbon furnace atomisation.

A comparison of procedures that involve the use of either carbon rod or carbon furnace atomisation in order to determine, by atomic-absorption spectrometry, the level of gold in whole blood, plasma and serum from patients undergoing gold treatment for rheumatoid arthritis is described. A procedure using carbon furnace atomisation is preferred because of its simplicity and sensitivity. The detection limits for gold, obtained by using the preferred procedure, in serum, plasma and whole blood are 0.002, 0.002 and 0.004 5 µg ml–1, respectively. The relative standard deviations are 1.9% for 0.063 µg ml–1 in serum, 2% for 0.061 µg ml–1 in plasma and 7.3% for 0.030 µg ml–1 in whole blood. The method is used to confirm that most gold is carried in the serum fraction of blood, to determine the gold level in white cells and to demonstrate that the gold level in the ultra-filtrate is low.