Current SCIEX systems with recent Analyst (and I'm assuming SCIEX OS) have a feature called Scheduled Ionization.  It's an electronic version of a divert valve.  Instead of diverting early or late elution from HPLC to waste, the feature turns off the ion spray during a pre-determined time to reduce unnecessary contamination of the MS.  I believe this was implemented because when using a divert valve, sometimes the electrode can clog when there is no flow as solvent evaporates and dissolved materials (lipids for example) solidify in the electrode rendering it useless.  By using Scheduled Ionization, flow continues through the electrode at all times, but because it's not spraying, no ions are generated so nothing is going into the MS.  

Herein lies the problem for us.  When the system isn't spraying, it is dripping, which might be fine for the more aqueous methods.  For us, the lipids start building up on the probe and the tip of the electrode gets fouled over time, so the Scheduled Ionization isn't a practical solution.  What I want to propose is that you offer an alternative Scheduled Ionization, where the ion spray stays active, but the front-end ion optics are turned off.  Cone voltage?  I'm not sure on the specific names and voltages that steer ions to steer into the MS.  If you can turn the Ion Spray voltage on and off for Scheduled Ionization, it should be just as easy to turn on/off the voltages that steer ions into the MS, no?  

I would very much like to talk with someone about this and push for its implementation.  Measuring complex lipids by LC-MS is really hard on the front-end of the instrument (a 6500 in our case).  This is especially true for the higher-end platforms that have larger orifices.  Having a scheduled ionization feature that is useful for lipid people would reduce contamination, thereby reduce service requirements.  This benefits the user and FSE/Service in reduced maintenance.  We are finding that aside from frequent cleaning of the early optics like QJet and Q0, we're seeing our Q1 foul to the point of replacement in less than one-year intervals.  Anything we can do to increase the intervals for cleaning and/or replacement would be beneficial.    

In summary, if Scheduled Ionization can be shifted from the electrospray to the ion optics (or have option for one or other) it will benefit everyone.  If you are already modulating one voltage, surely it can't be a difficult programming step to modulate other voltages (says the person who doesn't write code...)