|MadSci Network: Chemistry|
Unfortunately, testing for cyanide is not that easy. The usual way it is done is to react the unknown material (peach pits) with chlorine. Any cyanide present reacts with the chlorine to form cyanogen chloride. This then reacts with pyridine to form a dialdehyde (glutocondialdehyde). That is reacted with a special acid (1,3-dimethylbarbituric acid)to form a deep purple color (violet polymethine dye). The intensity of the color is related to how much cyanide was present to begin with. The GOOD NEWS is that there are simple test kits available that do all the chemistry for you. All you have to do is mash up the peach pits and let them soak in distilled water - stir occasionally. Then dip in a special paper strip or add a drop of a special solution and let the color change. You can then compare the color on the strip to reference colors on a card that comes with the kit. Unfortunately, the strips are fairly expensive. Strips are available from EM Science Products (www.emscience.com; 1-800- 222-0342) Cyanide Test Strips, 1-30 parts per million, EM Quant Part No 10044-1, 100 test strips, $64.45 Sometimes companies are willing to donate small amounts of supplies to schools for free. You or your teacher could give them a call and see if they'd be willing to send you a kit for free. Good luck!
Try the links in the MadSci Library for more information on Chemistry.