DIRECT DETERMINATION OF CHROMIUM IN BIOLOGICAL-MATERIALS BY SOLID-SAMPLING ATOMIC-ABSORPTION SPECTROMETRY - APPLICATION OF 3-POINT ESTIMATION STANDARD ADDITION METHOD

A new method Of PreParing calibration graphs (three-point estimation-s tandard addition method) is Proposed for the direct determination of c hromium at parts per million or sub-parts per million in powdered biol ogical samples by graphite furnace-atomic absorption spectrometry with a solid-sampling technique using a graphite miniature cup. Accurate a nalytical results for the direct determination of chromium have been o btained by the proposed method, and it was found that the calibration graph prepared by one sample has since been successfully applied to ot her kinds of biological samples. The analytical results by the propose d method are compared with the analytical results obtained by a conven tional calibration curve prepared by using a chromium standard solutio n and the standard addition method for solid samples proposed by Eames and Matousek (Anal. Chem., 1980, 52, 1248-1251). (C) 1994 Academic Pr ess, Inc.