Waters of course suggests that it's a quick and easy process to change between the MALDI and ESI source on the Synapt G2. It doesn't seem that way to us... But perhaps we're missing something. Can anyone with experience with this instrument please comment?
There is no real problem in the process, back and forth. First, you vent the instrument. Then, if you were in ESI mode, wait for a while (say, half an hour), for the source to cool. There's no need to wait in switching from MALDI to ESI. Then remove the source block (4 hex screws, one of which is particularly prone to wearing off.) Make sure that the four (4!) o-rings remain in place. Then fix the other source block in place, don't overtighten. Raise the MALDI source to the appropriate height and clamp in place; or fix the ESI source if the other way round. Pump the instrument. If within 5 min your turbos go to 50-60%, you have no source leak, and within half an hour to 45 min or so you'd be ready. Of course, this shouldn't be done every day. But once every few weeks is perfectly fine. Enjoy the fun.
Thank you for responding! We have had an opportunity to try the MALDI source and it was not too bad to swap the sources. However (this is a used system) there was a disconcertingly loud noise from the scroll pump when the system first began to pump down. It was serviced on install and I was not there to see if this is normal behavior. Can you comment on this? Also, about 15-20 minutes into the pump down, there was another loud noise coming from the instrument that concerns us. Our fear is that a swap between the sources requiring venting and pumping down may be reducing the lifespan of the instrument.
Any thoughts?
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