I want to build a low-cost polarimeter to study circular dichroism (chirality). What type of samples can I use? I am looking for samples that can be found outside the laboratory.
Sugars are very good: Sucrose, Glucose and Lactose give good rotations. You can also use camphor. You can also perform hydrolysis of sucrose with HCl and observe the change in rotation over time as it is hydrolysed to Glucose and Fructose.
Dorilian,
Optical rotation and circular dichroism are related, but not quite the same phenomena - the latter is a difference in UV-absorption between left and right circularly polarized light, and it is much harder to measure that optical rotation. You will need a dichrograph for this sort of measurement.
John's suggestions are pretty good; I can add that white table sugar is essentially very pure saccharose, and its aqueous solution is often used for the calibration of polarimeters. I am not sure if camphor is easily available outside the lab, but since it is not soluble in water, so you will need an organic solvent for it as well.
Thank you, John Hollerton and Vladimir Khlebnikov, for the recommendations for studying optical rotation. John's suggestion to observe the change in rotation over time is something that I will try. However, as mentioned by Vladimir, I am interested in circular dichroism. Since I don't have a UV source, I am looking for a sample that could show circular dichroism in the visible range (ideally at 633 nm).
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