Analytical and preparative separation of geometrical isomers by high efficiency silver nitrate liquid chromatography1

A packing technique in which carbon tetrachloride is the dispersing agent was used to pack high performance liquid chromatographic columns with 5 μm silica gel. The efficiencies obtained with analytical and preparative silica columns and AgNO₃-coated silica columns packed by this technique were compared. Special considerations were taken to minimize losses in column efficiency due to the chromatographic system. The AgNO₃-coated silica columns enabled the rapid separation of geometrical isomers of pheromones both analytically and preparatively. The highly efficient AgNO₃silica columns gave baseline separations of some isomers on a column 5 cm in length and resulted in the development of a column in which the percentage of impregnated silver ion was critical to the separation.