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

We compared results by two methods for serum Al determination: matrix modification with direct calibration in a stabilized-temperature platform furnace (Clin Chem 28, 2139, 1982) and a technique involving extraction with nitric acid before atomic absorption spectrometry (Clin Chem 30, 1216, 1984). 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 (mA X s per microgram/L), 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.