This test method covers atomic absorption tests applicable to powdered laundry detergents containing clay and zeolite. The test sample is fused with lithium metaborate, dissolved in acid, its silicon and aluminum content measured by atomic absorption, and the silicon/aluminum (Si/Al) ratio calculated. The clay and zeolite content of the test sample is calculated from the Si/Al ratio of the test sample and the Si/Al ratio of the clay and zeolite expected in the test sample. This test method is based on the linear relationship between the relative composition (or ratio) of clay/zeolite in detergent powders and the Si/Al ratio of such detergents.
