Elemental Composition of Zeolites by ICP-AES

This method is for the determination of components in zeolites by Inductively Coupled Plasma-Atomic Emission Spectroscopy (ICP-AES). Although the determination of silicon (Si), aluminum (Al), sodium (Na), potassium (K), calcium (Ca), iron (Fe), titanium (Ti), magnesium (Mg), phosphorus (P) and lithium (Li) is specifically addressed, many other elements, including trace contaminants, can also be determined. However, barium (Ba) and lead (Pb) cannot be determined in the digest due to the formation of insoluble sulfates. Barium can be determined from the fusion solution with a quantitation limit of approximately 0.01 mass-%. This method is suitable for samples containing less than 40 mass-% alumina (Al2O3) and less than 65 mass-% silica (SiO2); however, it can be readily expanded to samples with other silica/alumina ratios utilizing the same approach as described herein. Zirconium (Zr) at levels above about one mass-% can interfere with the analysis for aluminum when using some instruments, unless an alternative wavelength is used. Precision is about 1 to 2% relative standard deviation for elements present at concentrations greater than 0.1 mass-%, and mass balances between 98.5 and 101.5 mass-% are reported on a volatile-free basis. Precision below 0.1 mass-% does not exceed 10% relative down to the quantitation limits listed in Table 2.