can't get a peak in methanol-----please HELP

[ingewirawan]

I've just changed the column 8 months ago. And I used it around 15-20 injection every day.
If I see inside the GC, I don't think I used precolumn.

Do you have any recommendation, what kind of column that I should have?
Thank you so much

[WillyOne]

If you can change to capillary columns I can send that I'm doing now

[chromatographer1]

300 injections a month.

8 months! Would that be over 2000 injections? Maybe 3000 injections?

Hmmmmmm. What chemicals are found in wine? How many are not volatile?

How about spending a $150 and get a new column. Or maybe you should buy a $600 capillary which might last half as long.

Of course, you may drive your car 1,000,000 miles before trading?

Or use a razor blade 10 years before getting a new one?

You don't know how fortunate you are in your column buying.

Have a GREAT DAY.

best wishes,

Rod

[ingewirawan]

Is that better to buy the same column, or might be better to buy different column that has 20M carbopack B?
I heard the longest the column, it will hold the methanol better?
But if I changed with the 20M column, will my set up the same?

Thank you

[chromatographer1]

It might be better. Since I have not run your samples on the 5% Cwax 20M on Carbopack B you might wish to ask for chromatograms showing methanol ethanol and propanol peaks before you buy.

The lengths if different will mean different pressure to get the same flow, and then there are small differences from column to column to get the same flow. You will see little difference in your chromatograms with small pressure differences.

Supelco has chromatograms of this and other columns. If you have trouble finding them on their web site, just email their technical service people and they will respond quickly to you with a link you need.

best wishes,

Rod

[ingewirawan]

Thank you very much, Mr Rod for helping me.
I really appreciate with all your recomendation and suggestion.
I will buy the column that you recomended.
Thank you again.

Sincerely,
Inge

[Andy F]

I suspect you may run into trouble without some sort of temperature program for the oven because wine will have significant amounts (ppm) of less volatile compounds (higher esters and alcohols).

We use CP-Wax 57 with a program from 50°C up to 200°C.

[Axar]

Is your column made from steel or it is made from glass?

If you do not need a GLP you can excavete first 5 or 10 cm of stationary phase and repack it with fresh stationary phase. It is cheaper but if you use glass column you can brake it in the process.