Switching Columns

[CaChemGirl]

We are currently using an Agilent 6890N GC, packed column. We used to use an 80/100 Chromosorb 101, 3% carbowax 20M columns to detect ethylene chlorohydrin and ethylene glycol in water, but they don't make that column any more, so we ordered an 80/100 Chromosorb W HP, 10% Carbowax 20M column. I kept the method the same, and with the new column, we lost our EG peak, and the ECH peak comes off close to the solvent peak to have any detection. Any suggestions on what changed when I switched the columns and how to fix it?

[chromatographer1]

Yes, you went from a gas solid chromatography column to a gas liquid column. Don't use the column you have now. Replace it with another gas solid column.

You can probably replace the Chromosorb 101 with Hayesep P. You may wish to reduce the amount of Carbowax 20M or change that liquid phase to a lower Mole Wt Carbowax like C-Wax 1540.

When did Chromosorb 101 become obsolete?

best wishes,

Rod

[CaChemGirl]

Rod-

Thank you so much for your answer! That makes sense; I was driving myself crazy trying to figure things out!

Do you have a recommendation of a column we can use that's similar? The Chromosorb 101 probably went obsolete in December 2010; it's a perfect packed column for our needs, but we have no more!

[chromatographer1]

Yes, I gave you a recommendation with my last post.

Hayesep P 80/100 in the same glass or fused silica coated SS tube as you have before.

I would coat it with 1-2% Carbowax 1540 instead of the 20M.

Good luck,

Rod

[DSP007]

Hey, everything has changed.

Chromosorb 101 is a highly porous sorbent based on styrene-divinylbenzene resin. He has a huge area and has good absorbency. ECH with it at high temperatures slightly soluble, it absorbtion still increases the retention time.

Сhromosorb N-AW is a diatome (silica) sorbent, it have a small porous area , and EO and ECH not soluble in sorbent ( soluble only in Carbowax surface on porous)

What is douig?
It is best to order a similar column, or do it yourself. If you were in Moscow - "God told to share ... information " there are a couple of companies http://www.hromresurs.ru/price.html that can do this column. But outside of Moscow (Russia), this information is useless.

So you need to choose the temperature.
I think you need to do a temperature gradient from +60 C to +200 C and see where the EG and ECH come out (IMHO about 130C). And because of this "dance" by developing a new method.