![]() With continued use, the ligands are hydrolysed and eluted by the mobile phase, resulting in what is known as column bleed. On the other hand, the stationary phase itself is liable to degradation. These highly reactive groups can interact with the sample being analysed, resulting in distorted chromatographic peaks, low recoveries due to sample adsorption, shifting retention times and, in some cases, chemical degradation of the sample. ![]() The stationary phase cannot cover a hundred per cent of the silica surface, and a number of silanol groups remain exposed. Silica supports, however, have some limitations. But the real key to the success of silica particles has been the ability to modify their surface chemistry: through a process called functionalisation, a variety of organic stationary phases can be grafted on the particles, resulting in a truly versatile range of columns. Among the interesting properties of this material are mechanical strength, controlled pore size and volume, and high surface areas. Through a sol-gel condensation, precursor molecules such as TEOS (tetraethoxysilane) are condensed and cured to produce microscopic spherical silica particles. The most common solid support currently used in analytical liquid chromatography is, without a doubt, silica. But the Showa people perfected their art to the point that, in 1974, they decided their columns were good enough to sell, and Shodex was born. That was not strange at the time: there were no commercial column suppliers, so every lab would produce and pack their own. In the 1960s Showa Denko started to produce synthetic polymers, and their quality control lab made their own size exclusion columns. Your favourite soft drink could very well come in a Showa Denko can. Today, they manufacture products as varied as industrial chemicals and gases, ceramic materials, electronics, or aluminium. Shodex is the chromatography brand of Showa Denko K.K., a Japanese group of companies that began its history in the 1930s manufacturing fertilisers. With this new addition we complement our vast range of products with a complete family of polymer-based columns, designed for reversed phase, HILIC, ion chromatography, size exclusion, and more. Element became a distributor of Shodex HPLC columns at the beginning of 2019.
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