UV-Vis (ASD)
This manual is meant to complement your training and is not intended to replace on-the-job training.
WPC Activity Associated
Training Contact(s)
Anne Pham
alpham@lbl.gov
67-4115
x5526
Tracy Mattox
tmmattox@lbl.gov
67-4111
x2649
Last Updated
05/01/2015
OPERATING PROCEDURE
Operating the QualitySpec® Pro UV-Vis Spectrometer
Important: Never bend any of the optical cables that run from the light source to the chamber and from the chamber to the QualitySpec® Pro. This can cause permanent damage.
I. Important Features of the Instrument
II. Powering On the Instrument
· Turn on the QualitySpec® Pro (the power switch is located on the back near the top)
· Turn on the light source
· Turn on the laptop if it’s not already on
· Start the Indico Pro application from the icon on the desktop
o Note: This program will close unexpectedly if you left click in any of the empty grey areas of the screen (not including the axes).
III. Obtaining Your Spectrum
· Click on the "new" button at the top left of the screen to start a new project.
· Enter your project name and click OK.
· Enter a description (optional) and click OK.
· Verify that the instrument is connected. In the bottom right corner, find the connection status icon and mouse over it. It should read “Connected to 10.1.1.11”
· Set the number of samples to average. In the Spectrum menu, select “Sample Count/Average” and set the “Instrument sample count.” In most cases, a number of samples between 10 and 25 will do. If you find that you are not getting an adequate signal to noise ratio, try a higher number of samples.
o From here, you can also set the number of subsets to collect. If you set a sample count of 15 and the number of subsets to 3, then the instrument will take a total of 45 scans in batches of 15, average each subset of 15 together, then average together the 3 subsets for your final spectrum. This can further increase your signal to noise ratio.
· Prepare to take your baseline spectrum. If you know that your solvent will not absorb in the region of interest, make sure the cover is on the sample chamber and leave it empty. If your solvent will absorb in the region of interest, or if you’re not sure, fill a cuvette with just your solvent and load it into the chamber to use as a baseline.
· Make sure the cover of the sample chamber is closed, and collect your baseline spectrum. Click the "baseline" button, then click Yes. You should see a straight line across the screen at 1.00 transmittance. The software is now automatically subtracting your baseline from all scans you run until you either set a new baseline or close the program.
· You should not see an alarm about saturation. If you do, contact Alyssa Brand (x5526) or Tracy Mattox (x2649).
· Load your sample in the chamber and replace the cover. Use the solid sample holder if you’re using a solid sample.
· To collect your spectrum, click the button.
IV. Display Modes, Axes, Views
· Display Modes: To select these options, go into the Display menu.
o Y-axis Units
§ Digital Numbers (default)
§ Reflectance (including 1st and 2nd derivatives)
§ Transmittance (including 1st and 2nd derivatives)
§ Log(1/R) (including 1st and 2nd derivatives)
§ Log(1/T) (including 1st and 2nd derivatives). With no derivatives, this option is equivalent to Absorbance.
o X-axis Units
§ wavelength (cm)
§ wavenumbers (cm-1).
· By clicking on the spectrum line at any point, you can see the wavelength or wavenumber at that point on the spectrum.
· To zoom in and view only a small section of your spectrum:
o In the Display menu, select Axes. Set the minima and maxima to the desired portion of your spectrum, then click OK and the program should display only the ranges you selected.
V. Project File Management
· You can open files for direct comparison by clicking the "view" button. They need not be in the same project. However, if you save your project with other files open, they will be automatically saved into your project. This is a quick way to add new files to your project from other sources if you want to.
· You can remove unwanted files from your project through the Display menu. Choose the Show File List option, and from there you can delete files that you do not want in your project. Use the large black arrows to change which files are currently being displayed. You can only remove files that are not currently being displayed.
VI. Exporting Spectra for Further Analysis
If you would like to perform further analysis of your raw spectral data in a database or spreadsheet program such as Excel, you can export your files.
· From the Spectrum menu, choose Export Spectrum.
· Choose the ASCII tab. Make note of the “field separator.” You will need it later.
· Click OK and choose a file name and location.
· Open Excel.
· Click the Open button (or go to File -> Open). The file you just exported in Indico Pro is a basic text file, so you will need to change the “Files of type” pull-down menu to “All Files.”
· Find your exported file and click Open.
· On the next screen, make sure the “delimited” option is selected. Click Next.
For the Delimiter, select the same symbol that was used as the “field separator” in the export process in Indico Pro. Check the preview at the bottom of the dialog box to make sure it looks right.
· Click Finish, and all of your data should be arranged in columns in your spreadsheet.