Firing up the Mass Spec
Met Emma at the UWPR in South Lake Union; she brought our samples & the acetonitrile that we used for our samples.
We transferred our samples into labeled autosampler vials. NOTE: next time we need to bring empty autosampler vials for our blanks!!!
Notes from Emma’s Lumos testing:
Column packed to 30 cm and trap packed to ~3 cm with Dr. Maisch C18
Attach trap to mass spec with frit on mass spec side
test flow through trap - in BSM switch to trapping, set to 5% A, 0.2 flow then up to 0.5, ~200 psm
attached 30 cm analytical column - analytical flow, 5% solvent B (ACN), flow at 0.2 Lost pressure at 3500 but can’t see leak switch back over to trapping, 5% A, 0.2 flow See leak on trap input side; reattaching trap run solvent through on trapping, 5% A, 0.2 flow That seemed to hold, so changed flow to analytical, 0.2, 5% B, ~1300 psi analytical flow (50% ACN, 0.2 flow) and let run 10 minutes, ~1300 psi
pressure crashed, I think it is the analytical column so I replaced with a new one Equilibrated analytical column with 5% B, 0.2 ul/min flow let run for 10 minutes once solvent droplet visible at column tip (~2700 psi) switch to 5% A, 0.2 ul/min flow for 10 minutes (~2600 psi) switch to 50/50, 0.2 ul/min flow for 10 minutes (~1200 psi) up to 0.3 flow, ~3500 psi cut analytical column to ~27 cm switch back to 5% ACN for 10 minutes, 0.3 flow (~4200 psi but no leaks!)
Even with the high pressure at the 5% ACN, 0.3 flow rate I am going to see how the first QC injection goes - forgot to re-attach voltage until halfway through