Preparation of Bis-Tris from Tris(hydroxymethyl)aminomethane

2021/07/20 16:00
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Tris is an important biochemical raw material, and it has a wide range of applications. One of them is as a biological buffer, such as Tris buffer, Tris-HCl, TAE electrophoresis solution, Bis-Tris, etc. This article introduces the use of Tris Preparation of Bis-Tris (Dihydroxyethylaminotrimethylolmethane) method.


Tris method of preparing Bis-Tris:

1. Dilute 5 grams of sodium bisulfite with 10 milliliters of water and prepare a sodium bisulfite solution, put it into a 500 milliliter three-necked flask, then add 50 milliliters of absolute ethanol into the three-necked flask to mix, and then add the ethylene oxide Pass the alkane gas into the three-necked flask to fully absorb the alcohol solution containing sodium bisulfite to make it a saturated aqueous solution of ethylene oxide, and make the saturation solution not less than 8%, generally between 8%-20% ;

Biological buffer raw materials

2. Take the three-necked flask for use, take 100 ml of the saturated ethylene oxide solution prepared in step 1 into the three-necked flask, heat to 30-35 degrees, then take 60 g of TRIS and pour into the saturated solution of ethylene oxide , Make it dissolve slowly; after reacting for 2 hours, take 20 grams of sodium hydroxide and 20 ml of water to mix and drop them into a three-necked flask containing the above solution, so that the pH value of the solution is always controlled between 9.5-10.0. And continue to react for 6-8 hours;


3. After vacuum dehydration and hot filtration of the solution after the reaction in step 2, add absolute ethanol for dispersion, cool down and wait for the product to precipitate, then white powdery Bis-Tris can be obtained. The prepared Bis-Tris has a molecular formula of C8H19NO5 and a relative molecular weight of 209.2.


Bis-Tris can ionize hydrogen ions in a small amount, has a weak acidity, and is suitable for a weak acid buffer system. Due to the introduction of two hydroxyethyl groups in Tris, there are more atoms that provide lone pairs of electrons, and it has the ability to complex some metal ions. EDTA or Bicine is similar.


Except that Bis-Tris is synthesized with Tris, the biological buffer TAPS is also synthesized with Tris and propane sultone, which is equivalent to Tris propanesulfonic acid. Desheng is a manufacturer of diagnostic reagent raw materials and can provide a variety of biological buffers, including Tris, Tris-HCl, Bis-Tris, Bicine, TAPS and other reagents.

Key words:
Tris buffer