Ferric chloride test - Wikipedia Ferric chloride test The ferric chloride test is used to determine the presence of phenols in a given sample or compound ( for instance natural phenols in a plant extract ). Enols, hydroxamic acids, oximes, and sulfinic acids give positive results as well. The bromine test is useful to confirm the result, although modern spectroscopic techniques ( e.g. NMR and IR spectroscopy ) are far superior in determining the identity of the unknown. The quantity of total phenols may be spectroscopically determined by the Folin - Ciocalteau assay. Contents 1 Technique 2 Chemistry 3 Clinical use 4 See also 5 References Technique The sample is dissolved in water, or a mixture of water and ethanol, and a few drops of dilute ferric chloride solution is added. The formation of a red, blue, green, or purple coloration indicates the presence of phenols. Where the sample is insoluble in water, it may be dissolved in dichloromethane with a small amount of pyridine. Chemistry Phenols form a violet complex with Fe ( III ) +, which is intensely colored. The colour may vary from blue, green or even red depending upon the nature of the phenol ( Fe - ( o - Ph ) 6 ) 3 - Clinical Use The ferric chloride test can be used to detect metabolites in urine in case of inborn error of metabolism such as phenylketonuria. Compounds such as phenylpyruvate increase in plasma and are excreted out via urine. Also, it can be used to detect salicylates in urine after aspirin overdose. See also Prussian blue assay, a similar test for total phenol determination References Jump up ^ `` Ferric Chloride -- Pyridine Test Page ''. Chemistry.ccsu.edu. Retrieved 2013 - 09 - 11. This chemistry - related article is a stub. You can help Wikipedia by expanding it. Retrieved from `` https://en.wikipedia.org/w/index.php?title=Ferric_chloride_test&oldid=773416439 '' Categories : Chemical tests Chemistry stubs Hidden categories : All articles with unsourced statements Articles with unsourced statements from April 2015 All stub articles Talk Contents About Wikipedia Deutsch Español தமிழ் 中文 Edit links This page was last edited on 2 April 2017, at 07 : 51. Text is available under the Creative Commons Attribution - ShareAlike License ; additional terms may apply. By using this site, you agree to the Terms of Use and Privacy Policy. Wikipedia ® is a registered trademark of the Wikimedia Foundation, Inc., a non-profit organization. About Wikipedia

Question: what is the purpose of the fecl3 test
Answer: to determine the presence of phenols in a given sample or compound