u/nintendochemist1

Hello!

We have decided to resurrect our ELSD that had been in storage since my predecessor. It works, and I’ve used ELSD once before, but that was many moons ago and I’d like to learn the tricks to optimizing it.

I know the gas flow controls the size of the aerosol/droplets, nebulizer temp is set to get as much of the aerosol as possible into the drift tube, and the drift tube is where the main evaporation happens. If I understand correctly, lower gas and thus larger droplets are better for sensitivity but are difficult to reproduce. Lastly, that you want the drift tube to be warm enough to evaporate the solvent but not vaporize the sample.

I guess my questions are:

1. Is the key to method development really doing a lot of runs changing one variable at a time? I know that seems kind of obvious, but that feels like a lot of time for optimization.
2. Is some liquid coming out of the elbow/siphon normal? I know too much can mess with the baseline, but I have also seen people say it is needed to seal the drift tube.

Thanks to anyone who can provide insight!

Hello,

I’m working on our LTQ again and haven’t seen the issue I described in the title before. Everything passed except those and I was surprised the zoom and ultra-zoom scans passed.

I am using HESI, with the default HESI tune file, and my previous master cal as my starting point but can’t get these two to pass no matter what I try.

My next move is to make sure the modulation is set okay on Monday, but I wanted to see if anyone else has seen this or maybe can think of something to try that i haven’t.

Thanks

Hello,

I am trying to use SII for Xcalibur 1.5 to control my Ultimate 3000 and LTQ MS. However, I cannot get the MS to be triggered to start the scan when the ALS injects.

I read in the manual of the autosampler that relay 4 for is used to trigger the MS. So, I put my cable there and attempted to select relay 4 in Instrument Configuration. When I check my method, that doesn’t show anywhere, and if I click Direct Control of the LC, I can only click on relay one.

Because of that, I tried assigning relay one for the MS and moved my cable there but no luck.

Can anyone provide any insight? Do I need to put a command in the script editor?

Hello,

I am trying to use SII for Xcalibur 1.5 to control my Ultimate 3000 and LTQ MS. However, I cannot get the MS to be triggered to start the scan when the ALS injects.

I read in the manual of the autosampler that relay 4 for is used to trigger the MS. So, I put my cable there and attempted to select relay 4 in Instrument Configuration. When I check my method, that doesn’t show anywhere, and if I click Direct Control of the LC, I can only click on relay one.

Because of that, I tried assigning relay one for the MS and moved my cable there but no luck.

Can anyone provide any insight? Do I need to put a command in the script editor?