Analysis of finished methanol
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What conditions are required for chromatographic analysis of finished methanol? What is the relationship between basic methanol, acidic methanol, and the mass of methanol?
GB 338—92 Methanol **Standards and Analysis Methods http://bbs.hcbbs.com/viewthread.php?tid=122151&highlight=%BC%D7%B4%BC
A hydrogen flame detector + capillary should work; polar columns such as PEG-10M or FFAP can be used for the column. Feel free to contact me if you have any questions
Chromatographic analysis is used to examine the finished methanol product; the relevant standards are GB/T 683-2006 \"Methanol as a chemical reagent\" – which outlines the methods for measuring and calculating alkaline and acidic methanol – as well as GB/T 683-2006 \"Methanol as a chemical reagent\" and GB 338-2004 \"Methanol for industrial use\". Free download addresses: GB/T 683-2006: http://www.bzfxw.com/soft/softdown.asp?softid=9610; GB 338-2004: http://www.bzfxw.com/soft/softdown.asp?softid=6665
Whether it is alkaline or acidic, it has no impact on the quality of methanol. As specified in GB338-2004, there is a test for acidity or alkalinity; this merely indicates whether the methanol is slightly acidic or slightly alkaline. As long as it remains within the specified range, it does not affect the quality of the methanol.
If the methanol product is acidic, it is due to the deep oxidation of methanol; the oxidation of methanol produces formaldehyde, which can further be oxidized to formic acid. It is recommended to put more effort into controlling the production process. What was said upstairs is correct: whether the pH is on the acidic or alkaline side has no impact on the analysis process, but it does affect product quality. As long as the requirements of users are met and national standards are satisfied, that’s sufficient.
There is no difference between acidic and alkaline methanol; it might be due to differences in the manufacturing process (just a guess). Let me explain our analysis method to you: we use a FID detector and a WAX capillary column; a temperature of 50 degrees is sufficient. Methanol, ethanol, toluene, and other impurities can all be detected using this method. For reference only. This post was last edited by limingshuguang on 2009-2-26 at 15:14.]
Thank you to everyone up above. So, what is the difference between domestic and imported methanol?
The chromatographic analysis of finished methanol you mentioned is likely intended to determine the ethanol content in methanol, and there are specific standards for this in GB338-2004. Factories use this method for testing, but in national standards, the ethanol content is not a mandatory parameter; it is determined through negotiation between the supplier and the buyer. Specifically, it is an HP-1 capillary column + FID detector. It can detect ethanol at the ppm level.
Can I understand it this way? Is the main difference between domestic and imported methanol in its ethanol content?