Re: What is Trommer's test all about?

Hi Kate,

I haven't been able to find out much about the specifics of Trommer's test for complex sugars, which puts me in much the same boat as Artem in his answer to a similar question. However, from what I have been able to find, Trommer's test sounds very much like the benedict's test for reducing sugars in that both tests produce oxides of copper that precipitate out of solution, resulting in a color change.

Trommer's test involves treating a sample with a strong acid (sulfuric acid) which results in the acid hydrolysis of disaccharides into mono-saccharides. The solution is then neturalized (usally with potash or soda, but hydroxide could be used, as in the benedict's test) and a solution of copper sulfate is added. Note that a solution of copper sulfate and hydroxide is kown as Benedict's Reagent. From is point, the same reaction occurs as in Benedict's test, and the extent of the color change is proprtional to the concentration of reducing sugars in solution.

I think that the difference between these two tests is that the Benedict's test will only react with monosaccharides, while the Trommer's test uses acid hydrolysis to generate those monosaccharides. So I would imagine that it would be important to do a Benedict's test for reducing sugars on a sample first to establish the starting level of reducing sugars before doing the Trommer's test.

Keep asking those questions!