Analysis of Colors

Instrumentation

Hewlett-Packard 8452A UV-Vis spectrometer
Location: REIC 245
UV-VIS REIC 245 Instructions

Perkin-Elmer Lambda 900 UV-Vis
Location: REIC 139
UV-VIS REIC 139 Instructions

Perkin-Elmer LS50B Fluorimeter
Location: REIC 139
Fluorimeter Instructions

Nicolette 6700 IR spectrometer
Location: REIC 139
Instrument Instructions

Resources

Skoog ‘n Holler.  Ch 13-14.

http://www.authorstream.com/Presentation/kunasahu1-1449875-analysis-of-coloring-agents/

colorants found in foods,drugs, and cosmetics
http://www.fda.gov/ForIndustry/ColorAdditives/ColorAdditiveInventories/ucm115641.htm

 

A Comprehensive Guide to Thin Layer Chromatography (TLC)
Contributed by: Matthew Vanagel, 2014
website: http://webbook.nist.gov/chemistry/
Content – This webpage not only describes the theory behind TLC and how to perform TLC, but it also includes a list of different stationary phases that can be used and states the chromatographic mechanism and what applications they are best suited for. It also describes some of the most common problems encountered while doing TLC and how they can be avoided/resolved.
Reliability & Usefulness – I think that this webpage is extremely reliable since it is hosted by UC Davis, a well respected institution. I tried to use TLC to identify pigments in a makeup product. I was unsuccessful, but this webpage helped me understand how to troubleshoot some problems commonly encountered when doing TLC. Also, I think its list of stationary phases and what each is best suited for can be useful.

 NIST Standard Reference Spectral Database
Contributed by: Matthew Vanagel, 2014
website: http://webbook.nist.gov/chemistry/
Content – This database contains general information, identifying names/numbers for a lot of compounds. It also contains reference spectra. The type of spectra available vary between different molecules, but UV-Vis, FT-IR, MS, etc. are sometimes available.
Reliability & Usefulness – This database is very reliable since it is maintained by the National Institute of Standards and Technology. I found it useful for searching for reference spectra to compare to experimentally obtained spectra. You might not find the specific type of spectrum you are after for every compound, but it has a lot of information. Another neat feature is that you can download 2d mol files of molecular structures which came in handy for preparing nice figures.

 

UV-Visible Spectroscopy Resources
Contributed by: Matthew Vanagel, 2014
website: http://www.chemguide.co.uk/analysis/uvvisiblemenu.html#top
Content – This site contains a bunch of good information about UV-Vis, including the theory, the analytical technique, and data interpretation. There is a very in depth look at what causes molecules to absorb light. It describes the relationship between observed lambda max and talks about the expected UV-Vis spectra for certain functional groups.
Reliability & Usefulness – I think this is a pretty reliable source. It was made by an accomplished chemistry professor in the UK named Jim Clark. I found it useful for understanding the theory behind the technique and for relating characteristic absorption patterns to functional groups. There is also a very succint page describing bonding and anti bonding orbitals as well as conjugation that proved to be a good refresher. Overall good site for learning or reviewing concepts related to UV-Vis spectroscopy.

TLC Guide
Contributed by: Olivia Rhines, 2016
website: http://orgchem.colorado.edu/Technique/Procedures/TLC/TLC.html
Content – This is a basic guide (with pictures) to preparing and developing TLC plates.  Also provides good information about selecting the correct solvent, elution order of functional groups, and how to calculate Rf. I think the most helpful section was the part on troubleshooting TLC experiments.
Reliability & Usefulness – I believe this is a reliable guide to TLC.  The page is hosted on an organic chemistry page from the University of Colorado at Boulder, Department of Chemistry and Biochemistry.  If you click around theres also a lot of good information on other lab techniques.

Content: The link below is a pigment data base from Lawrence Berkeley National Laboratory.  It contains a list of paints and their pigments as well at data sheets on the pigments, reflectance spectra and much more.
Reliability and Usefulness: This source is reliable. Besides being a reliable reference, it also provides defining feature data on pigments which could help to articulate a CYOA assignments.
Contributor: Pearson Brodie

5 thoughts on “Analysis of Colors

  1. Title – Database of X-ray diffractograms for a lot of minerals

    Source – http://rruff.info/

    Content – This is a database that has a ton of spectral information about tons of different minerals. You can search by mineral name, formula, and even fragments of the formula. There seem to be x ray diffractogams and raman spectra for most minerals. You can get the raw data for each spectra through the site too which can be helpful.

    Reliability & Usefulness – This website is overall, pretty reliable. It’s well organized and maintained. There are usually multiple diffractiograms for every mineral and some are better than others. So if you notice that a diffractogram for a particular mineral is very noisey or just looks odd, go back and see if there are other diffractorgams that have been submitted for that mineral. I found this database extremely useful for comparing peaks in experimentally obtained diffractograms to references. With reference spectra from this database, I was able to confirm the presence of some pigments in a makeup product and determine its mineral composition.

    Contributed by – Matthew Vanagel

  2. Title – UV-Visible Spectroscopy Resources

    Source – http://www.chemguide.co.uk/analysis/uvvisiblemenu.html#top

    Content – This site contains a bunch of good information about UV-Vis, including the theory, the analytical technique, and data interpretation. There is a very in depth look at what causes molecules to absorb light. It describes the relationship between observed lambda max and talks about the expected UV-Vis spectra for certain functional groups.

    Reliability & Usefulness – I think this is a pretty reliable source. It was made by an accomplished chemistry professor in the UK named Jim Clark. I found it useful for understanding the theory behind the technique and for relating characteristic absorption patterns to functional groups. There is also a very succint page describing bonding and anti bonding orbitals as well as conjugation that proved to be a good refresher. Overall good site for learning or reviewing concepts related to UV-Vis spectroscopy.

    Contributed by – Matthew Vanagel

  3. Title – NIST Standard Reference Spectral Database

    Source – http://webbook.nist.gov/chemistry/

    Content – This database contains general information, identifying names/numbers for a lot of compounds. It also contains reference spectra. The type of spectra avaialble vary between different molecules, but UV-Vis, FT-IR, MS, etc. are sometimes available.

    Reliability & Usefulness – This database is very reliable since it is maintained by the National Institute of Standards and Technology. I found it useful for searching for reference spectra to compare to experimentally obtained spectra. You might not find the specific type of spectrum you are after for every compound, but it has a lot of information. Another neat feature is that you can download 2d mol files of molecular structures which came in handy for preparing nice figures.

    Contributed by – Matthew Vanagel

  4. 1) This source provides great background of what UV-Vis spectroscopy is and the transitions that occur when the molecule absorbs light.
    2) Reusch, W. (2013, May 5). Visible and Ultraviolet Spectroscopy. Retrieved February 15, 2016, from https://www2.chemistry.msu.edu/faculty/reusch/VirtTxtJml/Spectrpy/UV-Vis/spectrum.htm
    3) On this site you kind find information on UV-Vis absorption spectra and what kind of transitions are typically occurring in the molecule when light passes through it. The website also talks about conjugation and how that effects the absorption properties of the molecule.
    4) I believe that this source is great for getting brief background on UV-Vis spectroscopy, it is quite detailed for how short it is. I believe that the source is reliable seeing as it was written by a professor at Michigan State University, most likely developed for one of his classes.
    5) Contributor: Kyle Milke

  5. TLC Guide
    Source: http://orgchem.colorado.edu/Technique/Procedures/TLC/TLC.html

    This is a basic guide (with pictures) to preparing and developing TLC plates. Also provides good information about selecting the correct solvent, elution order of functional groups, and how to calculate Rf. I think the most helpful section was the part about troubleshooting TLC.

    I believe that this is a reliable guide to TLC. The page is hosted on an organic chemistry page from the University of Colorado at Boulder Department of Chemistry and Biochemistry. If you click around there’s also a lot of good information on other lab techniques.

    Contributed by Olivia Rhines

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