JCE Online Journal of Chemical Education
 | Subscriptions  | Software Orders  | Support  | Contributors  | Advertisers  | 

JCE Print

JCE Digital Library

JCE Software

Only@JCE Online

About JCE


  Home > JCE Print > Journal of Chemical Education > Issues > 2001  > July  >
In the Laboratory
The Use of Disposable IR Cards for Quantitative Analysis Using an Internal Standard
Ramee Indralingam and Angelito I. Nepomuceno
Department of Chemistry, Stetson University, DeLand, FL 32720-3756

Cover
July 2001
Vol. 78 No. 7
p. 958

Abstract
Infrared spectroscopy is traditionally used to identify compounds and aid in structure elucidation. However, solid samples require tedious and sometimes messy preparation of KBr pellets or mineral oil mulls and solutions cannot be used because there are no solvents that do not absorb in the IR. Disposable IR cards have simplified sample preparation for IR spectrometry. Moreover, they allow samples to be preserved for long periods, so that results can be verified at a later time. We report an experiment suitable for the instrumental analysis portion of the analytical chemistry course. It employs an internal standard in order to utilize the disposable cards for quantitative analysis. We use potassium thiocyanate as the internal standard because it has few absorption bands in the IR and they do not interfere with the bands of the unknown, benzophenone. Acetone is used as the solvent because it evaporates readily, making no contribution to the spectrum. This lab is useful as a teaching tool to illustrate the use of internal standards and calibration curves and the principle of Beer's law. It can be adapted for the determination of any analyte, provided the analyte and internal standard have distinctly separate IR bands. It is particularly useful in areas such as forensic chemistry, in which lab results are likely to be contested and samples must be preserved for long periods of time.
Supplement
The detailed experimental procedure, notes for the instructor, and some typical results are available.
*  Contents JCE2001p0958W.doc (MS Word)
*  Download
JCE2001p0958W.pdf

JCE2001p0958W.zip

JCE2001p0958W.sit

More Information
*  Citation
Indralingam, Ramee; Nepomuceno, Angelito I. J. Chem. Educ. 2001 78 958.
*  Keywords
Analytical Chemistry; Instrumental Methods; IR Spectroscopy; Laboratory Instruction
*  History
Created:
Last Updated:
June 6, 2001
August 31, 2005
  Home > JCE Print > Journal of Chemical Education > Issues > 2001  > July  > Page 958


Subscriptions

JCE HS CLIC

Our Secondary School editors work hard to distill all the JCE materials to produce a fraction of particular interest to high school teachers. We call it CLIC.


Contributions Welcome
JCE welcomes your submission

Advertisers
In recent years we have worked hard to better match our advertisers with our readers. When shopping for chemistry education materials, visit our advertisers' WWW sites first.

Be An Ambassador
Take JCE along on your outreach missions. Copies of the Journal, guest access to JCE Online, our publications catalog, and more are available for your participants.