Simultaneous multielement analysis of zeolite catalysts by inductively-coupled plasma atomic emission spectrometry

A method comprising digestion of zeolites with an acid mixture followed by inductively-coupled plasma atomic emission spectrometry (ICP-AES) has been established for the simultaneous determination of Al, Na, La and Si in various zeolite samples. Various aspects including sample digestion, instrumental interference effects as well as analytical performance and applicability of the established method have been investigated in detail. The results indicated that aqua regia in combination with hydrofluoric acid was effective for decomposition of a wide variety of zeolite samples. The effects of borate and fluoride ions in the digested sample solution on the ICP-AES determination have been carefully investigated. The method established will be generally applicable for the simultaneous determination of Al, Na, La and Si in zeolite with a precision of ≤5%. The analytical results obtained were checked by comparison with classical wet chemistry methods and found to be in reasonably good agreement. Application to the kinetic study of La-NaY exchange reaction was also performed.