Prepare GC/MS For Column Maintenance

We do not vent the MSD. We turn the inlet temp off then when it is cool we turn the flow off. Then take it out and clip it, install a new ferrule if necessary, reinsert, tighten, and turn the flow back on to make sure pressure holds ok, then turn heater back on.  Then we can bake it out or run a blank.

We do not vent the MSD. We turn the inlet temp off then when it is cool we turn the flow off. Then take it out and clip it, install a new ferrule if necessary, reinsert, tighten, and turn the flow back on to make sure pressure holds ok, then turn heater back on.  Then we can bake it out or run a blank.

Hi Garyb,

I am not agree with this becuase if any one just remove the column from inlet and trimming or changing inlet consumables and during that time there is no flow in column and its connected with MS then vaccum suction of ms may deteriote column performance or may damage column.

Without vent, there are so many technologies like quick swap etc can be used in GC where Aux flow supplied to maiantain pressure and vaccum of ms and column can be removed from quick swap fitting without vent.

If you have time to wait all day to pump down again that's fine. When you have a lot of rush samples you don't have that luxury. We have done it that way for 25 years with no problems.

Yes..Tips and tricks work based on environment and situation also.

But there is always pros n cons..if succeed then okay otherwise what is recommended in manual, has to follow.

I am happy that you succeed to use instrument without vent...

Hello, I understand you disconnect only the injector side of the column in order to trim it. Just be careful not to break the column closer to the transfer line because the sudden high flow can damage the pump and the oxygen entering can oxidize the hot parts of the MSD. It happened to me once...

Indeed, venting the system is annoying due to the time lost in cooling/heating the hot parts, slowing down the pump, recovering vacuum, air and water entering the system and possible leaks appearing.

I don't like to loose vacuum so I created a maintenance.M file where the hot parts of the MSD are at 100ºC in order to avoid oxidation when oxygen might get in the column (column must be cool or it will be damaged by oxygen). When I need to completely remove the column, I vent the system until the pump is at 40% speed, disconnect the column, plug the transfer line and pump down. The problems mentioned above are reduced and, especially, no leaks will appear.