Al-containing acidic and basic sodium aluminum phosphate preparation and use in studies of oral aluminum bioavailability from foods utilizing Al as an aluminum tracer

We synthesized Al-containing acidic and basic (alkaline) sodium aluminum phosphates (SALPs) which are FDAapproved leavening and emulsifying agents, respectively, and used them to determine the oral bioavailability of aluminum incorporated in selected foods. We selected applicable methods from published syntheses (patents) and scaled them down ( 3000and 850-fold) to prepare 300–400 mg of each SALP. The Al was incorporated at the beginning of the syntheses to maximize Al and Al equilibration and incorporate the Al in the naturally-occurring Al-containing chemical species of the products. Near infrared spectroscopy (NIR) and X-ray powder diffraction (XRD) were used to characterize the two SALP samples and some intermediate samples. Multi-elemental analysis (MEA) was used to determine Na, Al and P content. Commercial products were included for comparison. Satisfactory XRD analyses, near infrared spectra and MEA results confirmed that we synthesized acidic and basic SALP, as well as some of the syntheses intermediates. The Al-containing acidic and basic SALPs were incorporated into a biscuit material and a processed cheese, respectively. These were used in oral bioavailability studies conducted in rats in which the Al present in blood after its oral absorption was quantified by accelerator mass spectrometry. The results showed oral Al bioavailability from acidic SALP in biscuit was 0.02% and from basic SALP in cheese 0.05%, lower than our previous determination of Al bioavailability from drinking water, 0.3%. Both food and water can appreciably contribute to the Al absorbed from typical human Al intake. 2005 Elsevier B.V. All rights reserved. 0168-583X/$ see front matter 2005 Elsevier B.V. All rights reserved. doi:10.1016/j.nimb.2004.12.130 * Corresponding author. Tel.: +1 859 257 4855; fax: +1 859 323 6886. E-mail address: [email protected] (R.A. Yokel). 472 R.A. Yokel et al. / Nucl. Instr. and Meth. in Phys. Res. B 229 (2005) 471–478 PACS: 06.60.Ei; 82.30.Nr; 07.57.Ty; 07.85.Jy