Determination of Al, Si and P in certified reference materials by instrumental neutron activation analysis

Abstract

Neutron analysis activation is not commonly used for aluminum, phosphorus and silicon determination, due to the difficulty to obtain reliable results. In this study, Al was determined by measuring 28Al and the contribution of P and Si due to 28Al formed in 31P(n,α)28Al and 28Si(n,p)28Al reactions were corrected using correction factors determined experimentally. Phosphorus was determined by measuring 32P (pure beta emitter) formed in reaction 31P(n,γ)32P. Silicon was determined by epithermal neutron analysis activation (ENAA) and measuring 29Al radionuclide formed in 29Si(n,p)29Al reaction. Aliquots of certified reference materials (CRMs) and synthetic standards of the elements were irradiated together, using the pneumatic transfer station of IEA-R1 nuclear research reactor. Results obtained for biological and geological CRMs showed good precision and accuracy with |Z-score| < 2 for Al, P and Si determinations. The detection limits for Al, P and Si determinations CRMs were also evaluated. Results obtained in this study demonstrated the viability of applying INAA procedures in the determination of Al, P and Si.