Aluminium Oxide Alumina

Although many metal oxides have been used for TLC, only aluminium oxide has found much use and is available from manufacturers as prepared plates. It can have a vastly different selectivity compared to silica gel since its surface is composed of positive and negative charge sites, with no equivalent to a silanol. Its activity is also very much tied, to the water content on its surface and it is also used with activation. Another difference in this sorbent compared to silica gel is the possibility of making it with a wide range of different pore sizes (6, 9 and 15 nm). Alumina can also be made with acidic, neutral or basic surface character, which provides a range of possibilities for use depending on the compounds being separated. Thus, with a basic layer, acidic components would not move at all, so selective separation (in this case, capture) can begin at the origin where the spotting is done. Thus, a completely different arsenal of analytical tools can be found with these layers and in method development the different layers can be tried side by side to determine the effect of the different surface pHs.

The various-pH alumina layers have been used for separations of alkaloids, amines, antibiotics, lipid, nucleosides, pigments, polyaromatic hydrocarbons, steroids and surfactants. Many researchers seem to fear possible decomposition of components on alumina layers, but this is probably an unfounded myth, and would be just as possible on any high surface area exposed to an oxygen-containing atmosphere and a laboratory with fluorescent lighting.

Solar Panel Basics

Solar Panel Basics

Global warming is a huge problem which will significantly affect every country in the world. Many people all over the world are trying to do whatever they can to help combat the effects of global warming. One of the ways that people can fight global warming is to reduce their dependence on non-renewable energy sources like oil and petroleum based products.

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