“…A method for determining the optimum water and acid concentration in solvent systems for inorganic separations has been described (186), and in buffered-paper chromatography, the pH for optimum resolution of organic electrolytes can be calculated (1104,1246). Evidence has been presented that chromatographic separations on impregnated glass-fiber paper may be based on partition if phosphate buffer is used, but on adsorption if it is impregnated with silicic acid (529).…”