I was researching what is known as residual gas analyzers, commonly used as "pressure gauges" for ultra high vacuum systems which are basically small rugged linear quadrupole mass spectrometers, and got interested:

Would it be possible to convert a RGA into a general purpose mass spectrometer?

Granted, it will probably be optimized for low M/z molecules, but on the other hand, they're orders of magnitude less costly than 'real' MSs, and they likely has less stringent requirements for the vacuum. I don't intend this instrument for any kind of QA use, just as a private hobby project.

Mounting the unit in a KF flanged Tee manifold, vacuum pump (maybe a good, 2-stage rotary vane pump would be sufficient?), or small turbo pump, and a flat flange plate with a home made injection port, possibly coupled to a GC.

Has these instruments ever been used as such?

Thanks in advance,