The carbon rod atomizer in the analysis of clinical samples by atomic absorption

Abstract

In atomic absorption spectroscopy, the use of a flame to produce a population of ground-state atoms may have disadvantages regarding efficiency, sensitivity, and stability. Alternative non-flame methods have recently been developed, one such providing a simple and sensitive method for the determination of metals in blood samples. Samples of 1 μl or less are injected directly into a cavity drilled transversely through a carbon rod. The application of current to the rod causes the sample to be successively dried, ashed, and atomized, thus creating a brief absorption signal which can be quantitated. Using this technique on sample volumes of 0.5 μl. we have obtained good relative standard deviations for the determinations of plasma magnesium (3.7%) iron (1.3%) copper (1.1%) zinc (2.7%) and blood lead (2.9%). Excellent agreement with flame atomic absorption methods was obtained. We have also applied this method to the measurement of copper in small tissue biopsies. The technique has given good correlation with standard methods of tissue analysis when applied to samples of 1-2 mg. dry wt.