[Furanone]

Hi all,

I currently study starch, and a side project I am working on is researching the early history of starch research, which inevitably involves a lot of research about simple sugars (glucose and maltose) from learning that starch degraded with acid to sugars and with enzymes to glucose, maltose and various MW dextrins.

To be frank, I am quite amazed at what was known back 100 years ago considering the methods were very limited. Paper chromatography to separate the sugars was not available until 1943. Gas and liquid Chromatography came about 8 years later. Most of the experiments involved controlled degradation with enzymes or acids followed by analysis in a polarimeter (before & after methylation). However, another technique that is referenced a lot as early as the 1890s (that I have found) is the elemental composition (eg. % carbon, % oxygen and % hydrogen), which could be related to the molecular composition of glucose, maltose, etc. This was based on calculating the amount of CO2 and H2O I am guessing that was combusted from the original samples. However, nowhere could I find how the early carbohydrate chemists measured this so accurately, and I am very interested in this early technique. If someone knows how they accomplished this experiment with such great precision without such instruments as ICP-OES, I would really appreciate being educated about this.

Thank you.
Furanone

[fledarmus]

You might start here for some basic dates and technique:

http://en.wikipedia.org/wiki/Combustion_analysis

In essence, the material you are testing is burned in a pure oxygen source. The gases generated pass through a drying agent which absorbs all of the water, and through an aqueous base which absorbs all the CO₂. You then weigh very carefully the anhydrous material and the aqueous base, and calculate the weight of the water and carbon dioxide generated. From there, you can determine how much carbon and hydrogen was present in the original sample, and everything else is assumed to be oxygen.

There were a lot of very elegant testing methods developed that relied only on being able to weigh something very precisely.

[Furanone]

Thanks a lot mate. Exactly what I was looking for!! Cheers.