Estimation of gold in urine by atomic absorption spectroscopy.

The gold toxicity occasionally encountered during the treatment of rheumatoid arthritis by chrysotherapy may be conveniently treated with chelating agents to facilitate the urinary excretion of gold. It is of interest to monitor this urinary gold excretion, atomic absorption spectroscopy being a convenient technique. Although serum gold concentrations may be estimated after simple dilution (1), when the matrix effect caused by proteins may be compensated for by the addition of protein to the standards, urinary gold estimation does not allow such a simple solution because of variable molecular absorption.