| 词条 | Zeisel determination |
| 释义 |
The Zeisel determination or Zeisel test is a chemical test for the presence of esters or ethers in a chemical substance.[1][2][3][4] It is named after the Czech chemist Simon Zeisel (1854–1933). In a qualitative test a sample is first reacted with a mixture of acetic acid and hydrogen iodide in a test tube. The ensuing reaction results in the cleavage of the ether or the ester into an alkyl iodide and respectively an alcohol or a carboxylic acid. By heating this mixture, the gases are allowed to come into contact with a piece of paper higher up the test tube saturated with silver(II) nitrate. Any alkyl iodide present will give a reaction with the mercury compound to silver (II) iodide which has a red or yellow color. The reaction can also be used to determine the number of methoxy (-OCH3) groups,[5] by distilling the iodomethane into a solution of silver nitrate, which precipitates silver iodide. By filtering and weighing this precipitate it is possible to calculate the number of iodine atoms and hence methoxy groups. Synthetic applications: External links
References1. ^{{cite journal |doi=10.1007/BF01554683 |title=Über ein Verfahren zum quantitativen Nachweise von Methoxyl |journal=Monatshefte Für Chemie |volume=6 |pages=989–997 |year=1885 |last1=Zeisel |first1=S }} 2. ^{{cite journal |doi=10.1007/BF01516585 |title=Zum quantitativen Nachweise von Methoxyl |journal=Monatshefte Für Chemie |volume=7 |pages=406–409 |year=1886 |last1=Zeisel |first1=S }} 3. ^V Prey. Chemische Berichte 74 (1941) p350. 4. ^Lange. J Org Chem 27 (1962) p2037. 5. ^Ziesel Reaction 1 : Chemical tests |
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