Hey
this sounds a bit too much for me. Of course, it depends on your applications.
And btw. a better indication than time would be the volume pumped for priming
For me, this is what I normally do for start-up:
- keep all lines primed (at least filled with solvent), because all lines share a single vacuum chamber inside the degasser. If one line would be empty, the efficiency of the degasser could suffer (degassing the empty line not your solvent...)
- so normally I do a wet prime with about 15-25 ml (2-3 min @7.5 ml/min) on lines with replaced solvent, and about 10 ml on lines without any changes. So about 10-12 min in total.
(watch the system pressure to see when the air bubbles/new solvent reaches the pump-head, then wait the pressure to stabilize with the new solvent)
- Priming seal wash depends if I have replaced the solvent or if the line still looks ok. Then maybe just a few cycles
- Injector: I normally do a purge with MeOH as part of the "goto-standby" sample set, so the liquid inside the injector is exchanged too. Then when preparing the system, I check the syringe for bubbles, and if necessary, do an injector-purge with methanol for 6-10 loops with activated compression check. Maybe additional measures need to be taken to remove any sticky bubble from the plunger. Afterwards I include an injector purge at the beginning of the samples set with the runtime parameter of about 7 (needs to be between 6.5-15).
- Needle wash depends on the application, maybe give it 3-4 cycles, an check if solvent sputters from the yellow line (no steady flow is normal)
Preparing for runs is also straight forward.
- as my columns are normally in acetonitrile, I start with 100% (or close) of organic (ACN or MeOH) for about 10 column volumes or longer (wetting all the pores of a C18 column).
-- normally I do this in "manual mode", either directly on the 2695 or from the control panel in run sample
-- ramping up the flow just in one or two steps (e.g. start with 0.3 or 0.5 ml/min until pressure stabilize and check for leak, then go to final flow)
--- during this step, I can write the sample-set table
- then either manually change the composition to initial composition, manually or with <equilibrate> function in the sample set
- next do an injector-purge (runtime 6.5 – 15)
- then have the gradient run once with the <condition column> function, so the first injection has the same column equilibration as any other injection
-- special caution has to be considered when dealing with salty buffers, which may precipitate. Then introduce an high aqueous intermediate step when going to high acetonitrile
- as part of the "goto-standby" sample set, I normally do:
-- flush my column with about 10-20 column volumes of acetonitrile or appropriate storage solvent
-- do a wet prime for about 2 min (with default parameter of 4) on 100% MeOH
-- do an injector-purge with 100% MeOH, runtime ca. 7
-- if equipped with a column selector and bypass line, let about 3-5 ml of MeOH flow through the detector as well. (Otherwise let it sit in ACN until the column is removed.)
-- stop flow
-- if not used for longer period, replace (wet prime) the aqueous solvents with MeOH, remove the sample vials and power-off.
Doing so, I rarely have any problems with sticky check valves or when restarting the system