Determination of Metals in 100 µ I Sample Volumes by Atomic Absorption Analysis Using the "Spike-Height" Method of Absorbance Measurement1
Journal/Book: ANALYTICAL BIOCHEMISTRY 34 382-386 (1970). 1970;
Abstract: Department of Molecular Biophysics and Biochemistry Yale University New Haven Connecticut 06520 1This work was supported by Grant AM 09070-05 from the National Institutes of Health United States Public Health Service. 2The work described in this paper forms part of a dissertation submitted by H. W. Duckworth to the Graduate School of Yale University in partial fulfillment of the requirements for the degree of Doctor of Philosophy. H. W. D was the recipient of a predoctoral fellowship from Yale University. Since its introduction as a tool for the analysis of biological material by Allan (1) atomic absorption has been widely used to estimate many elements in biochemical research (2-4) . Depending an the element sensitivities ranging from 0.005 to 1.0 ppm may be achieved for biologically interesting elements using Instruments which are commercially available. Very frequently no sample preparation is required in the case of solutions apart from some enrichment if the concentration of the wanted element is extremely low. A difficulty which remains is that a certain minimum volume of solution usually 1 to 2 ml is required for a measurement. This is because the liquid sample is sprayed continuously into the atomizing flame and several seconds elapse before the steady-state level of light absorption is obtained. Lang and Herrmann (5) were able to reduce the volume needed to as low as 10 µl by using a direct nebulizer-flame assembly and a light ray oscillograph. This low volume was achieved by raising the concentration of the element being determined. Thus copper for instance which can be measured by conventional atomic absorption techniques at 0.2 ppm was detected with less than 10 µl of sample at the high concentration of 9 ppm. . . .