Chromatography Forum

good day to all.
I am currently studying about the multidimensional approach on GC.
honestly, the technique is somehow new to me as I have just started reading articles on MDGC.

I would like to ask, If somebody can help me understand as to how the mechanical switch valve works.

I've been trying to look for an article that explains the mechanism but I can't seem to find one that is free of charge.

I've already read a little about the Deans switch and I want to understand the basics of the mechanical switch valve so that I can compare and contrast the two properly.

Please help me.

There are three common valve designs, one is based on a mechanical rotor switching the flow paths, and the second is using plungers operated by pneumatic pressure to make the flow path changes. There is also a third design called a slider valve.

VICI is probably the most used vendor of the first type.

The other two are used by vendors of process GC analyzers which require months of operation without service to the valve. Most lab GC use VICI valves or those of similar design which require service much more often than the other two types.

Many are 6 ports in design, which is equal to 3 separate Deans switches.

Look at the Rosemont Analytical or Emerson Process Management web sitel

(connect the following 4 lines together in your browser.)

http://www2.emersonprocess.com/siteadmincenter
/PM%20Danalyzer%20Documents/
DAN_AN_DAN_BTU-Analysis-Using-a-
Gas-Chromatograph.pdf

best wishes,

Rod

If you are looking at traditional multidimensional GC, moving a few components from one channel to another, then I would also look at Agilent valve manual (G2739-90107) to see the various ways that valves can be used. If you are interested in comprehensive multidimensional analysis, I would look at www.chromatographyonline.com and search comprehensive. This will get you an article on Seeley's design as well as a number of other articles. I would also suggest you go to Leco's website and do a little looking around.

These are freely accessible.

Best regards,

AICMM

thank you for your help...
I found answers to thing that has been confusing me.
all the best

carl