Direct-calibration method for determination of aluminum in serum is comparable with the protein-precipitation technique

The authors compared results by two methods for serum Al determination: matrix modification with direct calibration in a stabilized-temperature platform furnace and a technique involving extraction with nitric acid before atomic absorption spectrometry. The two methods gave similar results with use of either a deuterium or a Zeeman system of background correction, but gave different slopes for standard additions, depending on the Al content of the serum, an effect not seen with aqueous solutions. These differences do not affect the accuracy of the Al determination up to 150 micrograms/L