Dear all,

I am wondering if anyone has the experience in connecting two columns to single MS. I have tried to connect them via a pressfit Y-connector. MS leak is found. Is it because the Y-connector is too close to the MS which the connection by simple pressfit cannot sustain high vacuum and thus causes leak. Please advise.

Uberto

Use a switching valve such as available from Alltech (or Agilent if 5890 or 6890) or accessory such as Restek No-vent or SGE MS-No vent. We had used 6890 with an automated Agilent/HP switching valve successfully with 5972 MSD, though once a year the $2 rubber O-rings in the pneumatic switching valve had to be replaced as the heat made them hard (if not, you'd have to switch manually with a screwdriver). Now we have 2 GC-MSD systems, we have a Restek accessory but haven't installed it yet (it doesn't require external helium supply).

Use a switching valve such as available from Alltech (or Agilent if 5890 or 6890) or accessory such as Restek No-vent or SGE MS-No vent. We had used 6890 with an automated Agilent/HP switching valve successfully with 5972 MSD, though once a year the $2 rubber O-rings in the pneumatic switching valve had to be replaced as the heat made them hard (if not, you'd have to switch manually with a screwdriver). Now we have 2 GC-MSD systems, we have a Restek accessory but haven't installed it yet (it doesn't require external helium supply).