Rapid and reliable method for the determination of aluminium in bone by electrothermal atomic absorption spectrometry

A reliable method for the determination of aluminium in bone by electrothermal atomic absorption spectrometry (ETAAS) is described. Bone samples were digested in concentrated HNO3 using a closed-vessel microwave digestion system. Accurate and precise results were obtained by calibration against aqueous Al standards prepared in solutions containing 1% v/v HNO3 and 1.0 g l-1 Ca, as Ca(NO3)2, as modifier. No modifier was needed for the bone digestate. A method detection limit (3 sigma) of 0.023 microgram g-1 for bone was obtained. The between-day precision for bone digestate was about 7% at a mean concentration of 10 micrograms l-1. The method was validated against the NIST standard reference materials SRM 1486 Bone Meal and SRM 1577b Bovine Liver. To help confirm the concept of the Al in bone method, essentially the same method, with some minor modifications, was used for the determination of Al in serum and dialysis fluid. The method performance was monitored by participation in two international interlaboratory comparison programmes for serum and dialysis fluid Al available from Canada (CHUL, Québec) and the UK (Robens Institute). The performance over a 10 month period was excellent for both serum and dialysis fluid proficiency test samples distributed by these programmes.