Using simple circuitry, polarizing film, and LEGO® toy bricks, an undergraduate physics student from the Ateneo de Manila University recently built an improvised polarimeter that can optically assess the purity of Vitamin C (ascorbic acid) and other chiral substances. The device has potential applications in classrooms as a learning tool, and may pave the way for more cost-effective means to monitor the quality of some consumer products.
Polarimeters are invaluable laboratory instruments that can help infer the purity of a chemical by measuring the angle of rotation of polarized light that passed through the test sample. However, laboratory-grade polarimeters are prohibitively expensive, with a high-end model costing over $11,500 and a commercial manual polarimeter priced at over $1,200. This makes their acquisition and use difficult if not impossible for small laboratories and classrooms in developing countries like the Philippines.