Estimation of Gold in Biological Fluids.

Chrysotherapy has now become a recognized form of treatment in rheumatoid arthritis and much experimental work has been done to determine the fate of gold salts in the body. Kling and his colleagues (1939) showed that gold compounds were deposited mainly in reticulo-endothelial cells, of which synovial membrane contains a large number. They were able to detect spectrographically the presence of gold in synovial fluids, even after the administration of such a small amount of gold salt as 350 mg. According to Rosenberg (1942), gold enters almost every cell in the body -shortly after injection, the greatest concentration being found in the liver, spleen, kidneys, and skin. Block and Buchanan (1940) claimed to have devised an accurate and specific microcolorimetric method for the determination of small amounts of gold in biological fluids such as blood and urine. This method has been used extensively by these workers and their colleagues to study the metabolism of injected gold salts (Block, Buchanan, and Freyberg, 1941, 1942; Freyberg, Block, and Levey, 1941, 1942; Freyberg, 1942; Freyberg, Block, and Wells, 1942; Block, 1944). They found that, when intramuscular injections of myochrysine were given at weekly intervals and when the dosage was kept at a constant level (100 mg.myochrysine, that is, 50 mg. gold) theconcentration ofplasma gold remained fairly constant (0*4 to 0 8 mg. per 100 ml.). Furthermore, during the period of administration much -of the gold was retained in the body. With a weekly injection of 50 mg. of gold, theaverage daily excretion, mainly in the urine, was 1 mg. Thus during treatment about 80 per cent. of the injected gold remained in the body. After a course of injections gold could be recovered from the blood and urine for long periods, even up to one year. During an investigation into the effect of BAL (2: 3-dimercaptopropanol) on patients receiving myochrysine for rheumatoid arthritis, we decided to use the method of Block and Buchanan (1940) to estimate the amount of gold in blood and urine before and during BAL administration. Their technique was carried out in the strictest detail. Method