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several questions about GC-MS from a novice

Posted: Fri Apr 11, 2008 9:15 am
by jqzhang
Hey, guys, I've just worked for a sole-ventured Japanese company in China mainland. In their lab, I found out that the technician seldom autotune or manually tune the Shimadzu GC-MS. When I use the Thermo product, it was recommended by the engineer that each time the MS be autotuned when you start up it. So I wonder whether the Japanese GC-MS is better than that USA tool.
I also can't understand that only one calibaration curve was used from march to now in 2008 for the purpose of quantitative analysis. I thought I'm an alian in that lab. it was said that the Japanese experts do the same thing in Japan. The company I worked in is a state -own one in Japan. So , please do me a favor to tell me I'm wrong. :?

Posted: Fri Apr 11, 2008 2:00 pm
by Kostas Petritis
What type are the MS that you worked and this one (i.e. ion trap, TOF, quadrupole etc?). If you worked with a TOF which is a high resolution instrument it is normal that you need to autotune everyday while other types of MS can go for months without any tuning...

Posted: Tue Apr 15, 2008 2:41 pm
by CE Instruments
Both Thermo and Agilent recommend an auto-tune on start up, in fact one of my customers complained that his 5973 would not run without it unlike his MD800. It is good practice to always run an auto tune on start up of the system no matter if one is not required. How could you be sure of your results on the Shimadzu if you never ran an auto tune, never run any unknowns ?