A unified method for the determination of gold in biological fluids by flameless atomic absorption spectroscopy.

A new simple non-flame method of assaying serum, urine, and synovial fluid for gold by atomic absorption spectrometry (AAS) is presented. Variable absorption not due to gold is avoided by wet ashing and extraction of gold into methylisobutyl ketone. The amount of gold is determined directly in the organic phase by AAS. A linear relation between standard concentrations for serum, urine, and synovial fluid and absorption meter read-out values is obtained over the ranges 0 to 800 microgram gold/dl in serum and 0 to 80 microgram gold/dl in urine and synovial fluid. The estimated calibration curves for gold in serum, urine, and synovial fluid are found to be identical. The elimination of interferences, the high sensitivity (0.01 ppm), and the simplicity make this method superior to any other AAS methods and excellently applicable for routine determinations of gold concentrations in patients on chrysotherapy, and for research in that field as well.