Is there such a type of chromatography column?
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A few days ago, I chatted with an instrument technician from a manufacturer, and he mentioned that there is a type of packing column in which, when analyzing the ethanol content in methanol, ethanol appears as a peak before methanol. But he forgot what kind of filler it was. I wonder if any of the sailors know; please let me know. It seems really amazing, hehe
It could be a highly polar packing column that utilizes the polarity of the hydroxyl group in methanol to achieve strong retention on the column. However, in practical analysis, using this separation method to analyze alcohols is certainly not a good choice. That is just an analysis method developed for the needs of specific applications.
This post was last edited by wolf1147 on 2010-8-14 at 11:25. The purpose of this type of analysis is actually to determine the ethanol content in methanol; since ethanol is present in trace amounts, around 10 ppm, it can easily be masked by the tailing effect of methanol if it appears as a peak after methanol. It is therefore advantageous in such analyses to have ethanol appear as a peak first
This column is actually the stationary phase specified in the national standard GB338-2004 for methanol analysis! Ethanol elutes before methanol; I used this column with a 6201-type support that has been acid-washed. Chromatography column: Preparation of the stationary phase – Weigh 30 g of sorbitol and place it in a 600 ml beaker; add 300 ml of methanol to dissolve it. Place the beaker on a water bath and heat it gently until the sorbitol is completely dissolved. Then add 70 g of acid-washed 6201-type support, stir slightly. After the methanol solvent has evaporated, place the mixture in an oven for drying, followed by screening before use. The packing and aging of the chromatography column shall be carried out in accordance with the provisions of 7.1.3 and 7.1.4 in GB/T 9722-1988.
Different polarities of the chromatography column result in different order of elution of the substances in the sample; the order of elution is not determined by molecular weight or boiling point. It seems that LZ needs to improve his knowledge of the basics of chromatography columns
Reply to 1# wolf1147: There’s a post here that discusses the polarity of common substances: http://wenku.baidu.com/view/9ba46f232f60ddccda38a0f0.html
You can also search on Baidu; for such simple questions, it’s better to try searching online by yourself, so as not to waste the forum’s resources