It has been some time since my last post. There are some good reasons for that, I have been traveling on the North American Seminar Tour. Look for posts on that later. Let’s start things up again with some training. There is one thing that we all must do on all GC-MS systems regardless of the instrument manufacturer, clean the source. There are tricks that we all come up with to make this job faster and easier for ourselves. I’m not sure all of the tricks make it easier but at least they seem that way. So for the training on source removal we will go through the following steps;
- Getting ready to remove the source
- Actually removing the source
- Parts of the source to clean
- Getting the source back into the instrument so you can actually use it again.
We will use the ISQ GC-MS Single Quadrupole as the instrument for the training. This will work with instrument that uses the ExtractaBrite Ion Source. Removing the source in this case only requires the use of the Source Removal Tool, there is no need to vent the system. The tool is attached to the front of the mass spectrometer and the Evacuate button is pushed. It is then possible to use the tool to remove the source. Once the source is out you should probably let it cool a little before you touch it, I do not want anyone to burn themselves. The source is easily taken apart. Make sure you clean all the metal bits like the repellor, ion volume, lenses, and the first part of the RF ion guide. To clean I use methanol and alumina oxide powder as the abrasive with a large cotton swab. Make sure that all of the burnt areas are cleaned. Using this combination makes getting any leftover residue off pretty easy by rinsing with solvent. You can sonicate the solid pieces in solvent, like repellor, ion volume, and lenses if needed. Does anyone have any specific techniques that work for them, I would like to hear about them.
Putting sources back together can be tricky and is always faster after you practice a few times. In this case the ExtractaBrite source will only fit together one way.
Like what you are learning?
Note: Do not lose the spring washer, you will need it (keeps the source from being all floppy). The source and the star washer are clipped together on the Source Removal Tool. Do not clip the star washer on to the source first if you are reinstalling the source immediately.
To put the ExtractaBrite Source back in the ISQ GC-MS connect the Source Removal Tool, with source attached, onto the front of the instrument. Press the Evacuate button, wait… then push the source into place. To get the full view of the source removal, check out the video.
Watch the video here, Source Removal