Estimation of gold in serum by atomic absorption spectroscopy.

The therapeutic use of gold compounds is of considerable antiquity, as discussed by Nineham (1); it has been used for the treatment of rheumatoid arthritis since 1927 (2). Treatment in the past has been largely empirical. Until the advent of the atomic absorption spectrophotometer the estimation of gold in biological fluids by classical chemical or other methods was beyond the capability of the clinical laboratory. Since then a number of authors have reported the estimation of gold in serum by atomic absorption spectroscopy (2). Few details of the method of Frajola and Mitchell (2) are given; Lorber et al. (3) use an internal standard method which, while it successfully compensates for matrix effects, requires relatively large amounts of serum. A. A. Dietz and H. M. Rubenstein, on the other hand, used a 1:1 dilution of serum and recognized the considerable matrix effects attributable to the presence of protein [Serum gold analysis. CLIN. CHEM. 15, 787 (1969), abstract].