CONTROL OF THE ELECTROOSMOTIC FLOW BY METAL-SALT-CONTAINING BUFFERS

New possibilities to suppress electroosmotic flow (EOF) were investigated. Buffers prepared from salts of zinc (up to 50 mmol/l), aluminium (up to 0.5 mmol/l) and barium (up to 250 mmol/l) lead to an effective reduction of EOF in Tris buffer, pH 7.4, 50 mmol/l. The dependence of EOF on different metal-salt concentrations is documented. The usefulness of barium-salt-containing buffers is demonstrated for pH values between 5 and 9.2. If the suppression is too strong, the EOF can be adjusted by mixtures of sodium and barium salts.