Gunzberg's test
{{Short description|Chemical test detecting hydrochloric acid}}
Gunzberg's test is a chemical test used for detecting the presence of hydrochloric acid. Gunzberg's reagent is made by dissolving two grams of phloroglucinol and one gram of vanillin in 100 millilitres of 95% ethanol. Hydrochloric acid catalyses Gunzberg's reagent to form a red complex.{{cite book|author=Chary|title=Practical Biochemistry for Medical and Dental Students|url=https://books.google.com/books?id=n52SyUqERrUC&pg=PA26|date=1 January 2004|publisher=Jaypee Brothers Publishers|isbn=978-81-8061-233-6|page=26}}{{cite book|author=Shankara|title=Practical Biochemistry 2008|url=https://books.google.com/books?id=nPphGdHO_XcC&pg=PA48|date=1 December 2008|publisher=Jaypee Brothers Publishers|isbn=978-81-8448-259-1|page=48}}
Procedure
Two drops of gastric juice are mixed with two drops of Gunzberg's reagent in an evaporating dish. The mixture is evaporated and if red is seen, free hydrochloric acid is present.{{cite book|author1=G. P. TALWAR|author2=L .M. SRIVASTAVA|title=TEXTBOOK OF BIOCHEMISTRY AND HUMAN BIOLOGY|url=https://books.google.com/books?id=LKy0weDEFp8C&pg=PA620|date=1 January 2002|publisher=PHI Learning Pvt. Ltd.|isbn=978-81-203-1965-3|page=620}}