The determination of low levels of aluminum in antihemophilic factor (human) preparations by flame atomic absorption spectrometry

Abstract

Aluminum hydroxide is used to adsorb extraneous protein during the preparation of Antihemophilic Factor (Human) (AHF). Removal of Al(OH)₃ is accomplished by centrifugation and filtration. This study describes a method for the determination of residual aluminum in AHF by flame atomic absorption spectrometry. Matrix interferences were minimized by employing sample digestion with HNO₃ prior to nebulization in a nitrous oxide-acetylene flame. Under these conditions, the limit of detection of aluminum in an aqueous system was estimated to be approximately 0·13 μg Al ml⁻¹, while the limit of quantitation was estimated to be approximately 0·56 μg Al ml⁻¹. Residual aluminum levels in AHF determined by this method ranged from <0·20 μg ml⁻¹ to 0·82 μg ml⁻¹. Butyl alcohol was used to modify sample matrices after digestion to increase the sensitivity of the assay system. An increase in the aluminum absorption signal was demonstrated after the addition of butyl alcohol to an AHF digest.