Polarimeter

概要

Source: Vy M. Dong and Diane Le, Department of Chemistry, University of California, Irvine, CA

This experiment will demonstrate the use of a polarimeter, which is an instrument used to determine the optical rotation of a sample. Optical rotation is the degree to which a sample will rotate polarized light. Optically active samples will rotate the plane of light clockwise (dextrorotatory), designated as d or (+), or counterclockwise (levorotatory), designated as l or (−).

手順

1. Preparing the Polarimeter

Turn on instrument and let it warm up for 10 min.
Make sure instrument is set to "optical rotation" mode.
Prepare a blank sample in the polarimeter cell (1.5 mL total sample volume, 1 dm in length) containing only CHCl₃. Make sure there are no air bubbles present.
Place the blank cell in the holder and press "zero."

2. Preparation of Analyte Sample

Prepare a stock solution of 10

結果

Representative results for the measurement and calculation of specific rotation for Procedures 1-4.

Procedure Step	Reading on polarimeter
1.4	0.000
3.2	+0.563
4.1	[α]₂₅^D = +77° (c 0.73, CHCl₃) Log in or to access full content. Learn more about your institution’s access to JoVE content here 申請書と概要 In this experiment, we have demonstrated the principles behind the polarimeter and how to measure and calculate the specific rotation of an optically active compound. The polarimeter is an important instrument in the fine-chemical and pharmaceutical industries to assess the identity, purity, and quality of a compound. It is specifically used for the measurement of optical rotation of chiral compounds, which can be used to distinguish the identity of two enantiomers by confirming whether it is Log in or to access full content. Learn more about your institution’s access to JoVE content here タグ Polarimeter Purity Assessment Chemical Properties Enantiomers Mirror image Variants Biological Activities Pharmaceuticals Drug Thalidomide Principles Of Polarimetry Setup And Operation Applications Organic Compounds Stereocenters Chiral Compounds Mirror image Isomers Enantiomers Physical Properties Optics 1. Preparing the Polarimeter Turn on instrument and let it warm up for 10 min. Make sure instrument is set to "optical rotation" mode. Prepare a blank sample in the polarimeter cell (1.5 mL total sample volume, 1 dm in length) containing only CHCl₃. Make sure there are no air bubbles present. Place the blank cell in the holder and press "zero." 2. Preparation of Analyte Sample Prepare a stock solution of 10-15 mg of the chiral analyte in 1.5 mL CHCl₃. Note the exact amount of compound used. 3. Measuring Optical Rotation Fill the cell with 1.5 mL of the prepared stock solution containing the sample. Place the cell in the holder and press "measure." The machine readout will give the optical rotation value. Remember to record the temperature as well. 4. Calculation of Specific Rotation The specific rotation of a compound is defined by the following equation: where α is the optical rotation value given by the polarimeter, l is the cell pathlength in dm, and c is the concentration of the solution in g/mL. スキップ先... 0:00 Overview 0:49 Principles of Polarimetry 3:51 Initialization of the Polarimeter 4:24 Calibration and Measurement 5:23 Applications 6:52 Summary このコレクションのビデオ: Now Playing Polarimeter Organic Chemistry II 99.8K 閲覧数 Cleaning Glassware Organic Chemistry II 123.1K 閲覧数 Nucleophilic Substitution Organic Chemistry II 99.1K 閲覧数 Reducing Agents Organic Chemistry II 42.7K 閲覧数 Grignard Reaction Organic Chemistry II 148.7K 閲覧数 n-Butyllithium Titration Organic Chemistry II 47.6K 閲覧数 Dean-Stark Trap Organic Chemistry II 99.7K 閲覧数 Ozonolysis of Alkenes Organic Chemistry II 66.7K 閲覧数 Organocatalysis Organic Chemistry II 16.6K 閲覧数 Palladium-Catalyzed Cross Coupling Organic Chemistry II 34.2K 閲覧数 Solid Phase Synthesis Organic Chemistry II 40.8K 閲覧数 Hydrogenation Organic Chemistry II 49.1K 閲覧数 Polymerization Organic Chemistry II 93.6K 閲覧数 Melting Point Organic Chemistry II 149.6K 閲覧数 Infrared Spectroscopy Organic Chemistry II 213.8K 閲覧数個人情報保護方針利用規約一般データ保護規則お問い合わせ図書館への推薦 JoVE ニュースレター研究 JoVE Journal メソッドコレクション JoVE Encyclopedia of Experiments アーカイブ教育 JoVE Core JoVE Science Education JoVE Lab Manual JoVE Business JoVE Quiz JoVE Playlist 教員用サイト著者概要出版プロセス編集委員会スコープと指針査読よくある質問お申し込み図書館員概要お客様の声定期購読アクセスリソース図書館諮問委員会よくある質問 JoVEについて概要経営陣ブログ JoVE Help Center JoVE Sitemap Copyright © 2023 MyJoVE Corporation. All rights reserved