By the use of a heated graphite atomizer, serum chromium concentrations can now be measured directly by atomic absorption spectrophotometry in 50-μl serum samples. Pretreatment or tedious extraction procedures of serum samples are avoided by this relatively simple, rapid, and reproducible method. Interference by other metals or salts in serum can be eliminated by this technique of selective volatilization. The coefficient of variability on a single pooled serum sample was 5.8%, and a value of 100.6% was obtained in recovery studies. When serum Cr concentrations were measured in a group of 15 healthy young adults, a mean serum concentration of 1.58 ppb (± SE of 0.08) was obtained. The results obtained can be attributed to the sensitivity of the analytical system, the reduction of possible sources of exogenous contamination, and the elimination of interference by other elements within the sample or system.
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