Embedded Files
Staff Contact: Anne Pham (alpham@lbl.gov)
Instrument Location: 67-4203A
Safety Points
Safety Points
You must be authorized to work under the "work on 4th floor" WPC activity (MF-0001) to operate this instrument.
Your staff contact must approve the materials you will be measuring.
NO sample prep is allowed in lab 4203A. All samples must be prepared in a fume hood with solvents sealed in capped cuvettes prior to use in the Cary-5000. (See your staff contact if you need a dedicated work space.)
The videos provided here offer guidance on using the instrument, but you must still coordinate with the staff member listed above to schedule a formal training.
Standard Operating Procedure
Standard Operating Procedure
This video walks you through the methods typically used to collect absorbance spectra using the Cary system on the 4th floor of the Molecular Foundry. The manual covers swapping out cuvette and film sample holders as well as data collection.
Integrating Sphere
Integrating Sphere
Once you are familiar with the software, you can use an attachment to collect reflectance measurements. This video explains how to safely install an integrating sphere into the Cary 5000, including instructions on how to perform an alignment check and how to load your sample.
COMMON QUESTIONS
COMMON QUESTIONS
Q: How do I get rid of the jumps in my data from the detector and source switchover (350 and 800nm)?
Q: How do I get rid of the jumps in my data from the detector and source switchover (350 and 800nm)?
A: This is an ongoing issue with our instrument, but there are a few options that can help.
If your collection range is close to the switchover points, just nudge the switchover by 100nm. For example, if you are collecting from 350 to 900nm, you can switch the detector and grating changeovers both to 900nm. (Remember this option is in the set-up and advanced settings window.)
Run your baseline with your reference solvent or your clean substrates in both of the sample holder positions, then recollect your spectra.
If that doesn't solve the problem, decrease the sensitivity of your detector by increasing SBW. Run the baseline and collect your data again. (Remember this option is also located in the set-up and advanced settings window.)
Q: Why are there different areas in my spectra with a lot of noise or extra peaks?
Q: Why are there different areas in my spectra with a lot of noise or extra peaks?
A: There are a handful of answers to this, and they are all pretty easy to pinpoint and troubleshoot. Here are the most common issues:
You are using the wrong cuvette for the range you are measuring. For example, if your cuvette has a spectral range of 340-2000nm and you try to measure out to 3000nm, you will likely start seeing noise or peaks that are not related to your sample above 2000nm. To confirm the problem is not your cuvette, run a baseline with air as the reference in both cuvette positions, then insert an empty cuvette in the front sample holder while leaving the back of the holder empty. If you run the same parameters and see a signal in the same troublesome region then it's definitely coming from your cuvette.
Your solvent or substrate are not transparent in your region of interest. This is easy to check. Rerun your baseline with air as the reference in the front and back of the sample holder, then insert your substrate or solvent into the front position of the sample holder and collect your data.
If you are measuring into the NIR range, you want to turn the instrument on about an hour before you need to collect your data. Warm lamps are happy lamps when it comes to clean getting a clean baseline!
Your solvent is contaminated. This is less common, but we do see it on occasion. Use the same trick as mentioned above, baseline with air or with empty cuvettes, then measure just the solvent as your "sample" and see if the mystery peak reappears. It's also possible the solvent you are using is not spectral grade or that your selected solvent has a signal even without a contamination problem.
Q: Someone is on the instrument but my name is reserved on the calendar. What do I do?
Q: Someone is on the instrument but my name is reserved on the calendar. What do I do?
A: If you reserved time on the calendar then you have the right to use the instrument. Everyone hears this same rule when they are trained. It is definitely okay to politely remind the researcher who is using your time that they forgot to make a reservation and have them come back later. If you don't feel comfortable asking the person to leave, feel free to contact Anne for an assist. She has no problem enforcing the rules so that everyone is treated fairly! :-)
Q: The integrating sphere is not giving me good signal. How can I improve this?
Q: The integrating sphere is not giving me good signal. How can I improve this?
A: Be certain you are using the appropriate amount of sample. If your sample does not cover the opening of the sample compartment you will not be happy with the results, which will be obscured. Powder samples must fill the 2" diameter opening and solution samples must completely fill the 10mm path length of your cuvette.
Looking for a printable manual to help you take notes? Look no further than here:
Looking for a printable manual to help you take notes? Look no further than here:
Standard Operating Manual
Standard Operating Manual
Cary 5000 standard operation.pdfIntegrating Sphere Instructions
Integrating Sphere Instructions
Cary 5000 integrating sphere.pdfPage updated
Report abuse