This method is for determining total fluoride in aluminosilicatecatalysts and molecular sieves, and inorganic fluoride in aqueoussamples. The method is particularly useful for catalysts containingzirconia or other metals that interfere with other procedures. Therange of fluoride typically determined is from 0.005 toapproximately 20 mass-% for catalysts or molecular sieves, and0.005 to approximately 50 mass-% for aqueous samples.