The base silica for Purospher® high purity HPLC columns is made from tetraalkoxysilane in a sol-gel process. Thanks to the absence of metals in the silica matrix, and an optimized surface coating and shielding process, Purospher® columns provide tailing-free separations of acidic, basic, and chelating compounds. This is of particular advantage for any kind of method development in Research and Development and Quality Control laboratories.