Abstract
A fast reacting atomic absorption spectrometer in combination with a carbon filament atom reservoir was used for ultramicroanalysis of calcium and magnesium. The analysis of 1 X 10(-12) mole of magnesium gave a variation of coefficient of +/-3% and analysis of 2 X 10(-11) mole of calcium gave one of +/-5%. The effect of adding various common biological substances to the samples in great excess was tested. No interference could be observed.