ICP-OES
(Agilent 720-ES)
Staff Contacts: Rachel Alvelais (ralvelais@lbl.gov)
Instrument Location: 67-4203B
Most Important Principles
You must be authorized to work under the "Work on 4th Floor" (MF-0001), "Strong Acids" (MF- ), and "ICP-OES" (MF-0010) WPC activities to operate the instrument.
There can be NO AMOUNT OF FLUORINE in your sample or standards. This is a very strict policy to protect the glass components of the ICP.
Use extreme caution when handling ICP standards and samples. Though the acid content is typically only 2-5% acid, the solutions still have a pH of 1 and can burn skin and damage clothing.
You must inform the staff contact of the elemental composition of your samples, not just the analyte of interest, prior to running your samples.
Your samples must be acidified to 2-5% acid (hydrochloric or nitric acid) for the instrument.
You must send the staff contact photographs of the peristaltic tubing, waste stream tubing, and the glass of the torch, PRIOR to turning the instrument on. Each time.
Your data is only as trustworthy and quantitative as your sample preparation and data treatment! Pay attention to signal-to-noise ratio, RSD, and replicates!
The video provided here offers guidance on using the instrument, but you must still coordinate with the staff member listed above to schedule a formal training.
Standard Operating Procedure
This video explains how to use the ICP-OES located at the Molecular Foundry. It focuses on instrument and software set-up, including an auto-sampler, but does not describe sample preparation. This instrument uses a 5% nitric acid wash solution and axial argon torch, and the operating methods described here include tricks we've learned to deal with the quirks of our software package.
New ICP Instrument Manual.docxCOMMON QUESTIONS
Q: It has been 20 minutes and the Peltier still hasn't cooled to -35 C. What is wrong with the ICP?
A: There are always two possible answers to this. 1) You are more efficient then you think you are and haven't reached the 20 minute mark from the time the system started purging. Wait another 10 minutes before you seek someone out for help. 2) You forgot to open the valve to the argon dewar on the wall. Don't worry, nine out of ten times it's the second on this list that is a problem. To fix it, open the valve, click on the hammer icon on the software and check that the Argon Flow says "ok." Now wait the required 20minute purge time and the peltier should cool with no other problems.
Q: I have a little tiny itty bitty amount of fluorine in the ligand in my samples. I know I cleaned it well, so is it okay to measure it on the ICP now?
A: NO AMOUNT OF FLUORINE is allowed to be run in the ICP. Even minor amounts react with your acid to form HF, which eats away at the nebulizer and torch.
Q: My samples won't digest/will precipitate in acid, can I dilute them with pure water? With base?
A: NO. Your samples MUST be 2-5% acid to be run in the ICP. If your sample is precipitating, it may require a different acid digestion method, or it may be incompatible. Contact the listed staff member to discuss solutions.
Q: Can I leave my standards next to the ICP? I might want to use them again next week.
A: Nope! Do not leave samples or standards next to the instrument. Too many people have abused the system, so you must either dispose of your samples upon completing your run or store them in your designated research area.
Q: Someone is on the instrument but my name is reserved on the calendar. What do I do?
A: If you are on the calendar then you have the right to use the tool. It's okay to remind people of this rule and ask them to leave... or ask one of the staff to step in. We don't mind enforcing the rules! :-)
Q: Solvent is not flowing through my tubing when I rinse. How can I fix this?
A: You may have put the tubing on the pump backwards. Double check it or ask for help. In addition, the tubing goes flat over time. Forgetting to dry the tubing causes problems as well as leaving the clamps connected (not releasing tubing pressure) after running the instrument. Unfortunately, if the tubing is flat that means the inside has collapsed and sealed off the opening, which prevents solvent flow. The only fix is to replace the tubing with a new one found in the second drawer under the autosampler.
Q: What do I do when the torch shuts itself off mid-run?
A: This happens on occasion. Check that your chiller and gas flow are okay and restart the torch. Let the torch stabilize for 20 minutes, then start again. If it shuts off on its own a second time, contact the staff member in charge of the tool. It's possible the torch is clogged and needs replacement and recalibration.
Q: How do I handle a message that the water flow is insufficient?
A: The water in the chiller evaporates over time. To stop the error, roll the chiller toward you, just far enough that you see the square opening on the top and can remove the access panel. Unscrew the white lid on the chiller and top the system off with tap water (NOT DI water). Screw the lid back on, resecure the square cover, and gently press the system back under the table. If this is new to you, please feel free to contact the staff member responsible for the instrument for assistance.
Instrument manuals, waste disposal, sample prep guides, and data troubleshooting.
General Shared Copy of ICP Sample Prep.docxICP manual.docxICP standards spreadsheet instructions.docICP WASTE INSTRUCTIONS.pdfICP standard form_UPDATED 2021.xls
