Sepration science in "chromatography" ON GAS CHROMATOGRAPHY

Chromatography Forum: GC Archives: Sepration science in "chromatography" ON GAS CHROMATOGRAPHY
Top of pagePrevious messageNext messageBottom of pageLink to this message  By Anonymous on Friday, February 23, 2001 - 09:58 am:

I WORKED ON GAS CHROMATOGRAPHY UP TO 6 YEARS
I AM ANALYTICAL SCIENTIST/CHEMIST.
MY QUESTION IS
IF TWO COMPOUNDS HAVE APPROX.SAME B.P/M.P.
(BIOLING POINT)
THAN WHAT WILL BE THE AZEOTROPIC CURVE VAPOUR LIQUID CURVE
NOW MY QUESTION IS THAT HOW IS THE QUANITTATIVE METHOD DEVLPOED IN SUCH CASE?


Top of pagePrevious messageNext messageBottom of pageLink to this message  By Anonymous on Monday, February 26, 2001 - 07:25 am:

If I am understanding your question correctly, you are wanting to know how a GC method can be developed when two compounds have the same boiling point. If you are using a column which separates only according to boiling point, the two compounds will elute at the same time. However, there will likely be functional group differences between the two compounds. There are column phases which tend to retain certain functional groups over others or will retain more polar compounds over less polar ones; even for compounds with the same boiling point. You can see this in chromatography catalog sample chromatograms by noting the change in retention order when different column phases are used. So even though the boiling points are the same, separation of the two compounds can be obtained with the proper choice of column phase. If hope this answers your question. Sorry if it doesn't.


Top of pagePrevious messageNext messageBottom of pageLink to this message  By Anonymous on Monday, February 26, 2001 - 02:32 pm:

If you are trying to separate compounds which are very similar in structure as well as bp, column choice and chromatographic conditions are critical. Try calling one of the column companies and give detailed information about the separation desired. They should at least be able to tell you how feasible the separation is. Some separations are very difficult without a special (expensive) column and a very specific GC program. With the information provided a specific answer is difficult.


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