In the Egypt's Eastern Desert intrusive rocks with U-REE mineralization (two-mica granites, microgranites, dolerites, and bostonites) are developed. We estimated the content of chemical elements in reference samples of intrusive rocks and also in their water-soluble (colloid-salt) fraction. This fraction is water-extracted from the rock under certain conditions. The rock sample and its colloid-salt fraction are analyzed using ICP-MS. The chemical characteristic of the extracted fraction reflects the mobile migrating part of the chemical elements in the composition of the rocks. Comparison of the obtained data allows us to estimate the share of migrating and weakly migrating elements.