Comparison of analytical techniques for the determination of silicon and aluminum content in zeolites

A study of comparing analytical techniques for the determination of Si and Al content of zeolites was conducted. Atomic absorption, neutron activation, and proton inelastic scattering analyses were found to be the most reliable. Data obtained from X-ray fluorescence (XRF), wet chemical, and inductively coupled plasma (ICP) spectrometric analyses showed that alteration in the methodology of these techniques was needed to improve their precision. The Si/Al determination by /sup 29/Si magic angle spinning nuclear magnetic resonance (MAS-NMR) is complicated by crystallographic imperfections. The percent Al content by /sup 27/Al MAS-NMR is generally consistent with the other techniques but can also be complicated by crystallographic imperfections and the presence of paramagnetic impurities.