Tris(hydroxymethyl)aminomethane is also called Tris or tromethamine. This is an important chemical raw material and biochemical reagent, and it usually looks like a pure white powder. Some customers have reported that some Tris in their warehouses have turned yellow. Why is this?

Tris is relatively stable when it is dry and sealed, and generally does not decompose, and it is not prone to deterioration. If Tris has yellowing, it can be judged from the following situations.

                                                         Tris(hydroxymethyl)aminomethane reagent powder

Is there a product quality problem: First, confirm whether the yellowing of Tris is the original product quality problem or the yellowing occurred during storage. There are two main synthetic methods for Tris. One is to react with methanol and dichloromethane and add a small amount of Raney nickel as a catalyst, and then use nitrogen to hydrogen conversion; the second is to react with nitromethane and excess paraformaldehyde, and then add Hydrogen is reduced under nickel catalysis. The raw materials and solvents used in the two synthesis processes are colorless, and the Tris products will not appear color when the equipment is clean.

Therefore, product quality problems are unlikely to cause the Tris to turn yellow, unless the raw materials used are of poor quality, contain colored impurities or the equipment is not cleaned to cause product contamination. If it is an insoluble solid particle impurity, you need to dissolve Tris before filtering and then using it.

Yellowing of Tris products during storage: The dry powder of Tris is not easy to decompose, nor can it be used by microorganisms as nutrients, so it is not easy to grow bacteria. However, Tris is easier to absorb moisture, and it will absorb moisture in the air faster when it has poor sealing and high humidity. After moisture absorption, Tris is alkaline, and it is very easy to absorb carbon dioxide in the air. In this case, it is easy to appear The problem of bacterial deterioration and yellowing.

The above are the possible reasons for the yellowing of Tris. If there are other reasons, please share with Desheng. The Tris produced by the company has no feedback of yellowing. Whether it is in barrels or bottles, the tightness is relatively good. Good, it will not cause moisture absorption and deterioration due to poor sealing.