Acetone grade

[Ryklys]

I would like any information and opinions on one issue. Our lab buy two different grades of acetone: for GC assey solutions and for rinsing of glassware. Our suplyer provides acetone from Sigma-Aldrich. That's 24201 (GC assay) and 34850 (GC assay).
The question is: if 24201 is GC grade do I really need to buy 34850, witch is mutch more expensive?
Thank you in advance.

[larkl]

YOu could run the acetone on the GC methods and see if you have any interferences.

[Peter Apps]

As far as I know the "GC assay" means that the quality has been checked by GC, not that it is specifically suitable for GC assays. Larkl's advise might save you some money.

Peter

[Ryklys]

Thank you.

I have used that lower price acetone for sample preparation already. Not on purpose but we have funny thing with supplyes sometims. I didn't notice any big diferences though. But my concern is another issue: is it safe for my columns to use that cheeper acetone? That cheeper acetone contains more water. About 4 times more. Like 0.19 % and 0.05 %. Colums are HP5 and HP35.

[chromatographer1]

Acetone and many other solvents contain water in small or trace amounts.

Acetone can also contain many materials not always seen by GC, it is a dandy solvent for plastics and other non-volatile materials.

Now for use in GC.......and you are concerned about water, and you dissolve your sample in acetone, is the water content of acetone a REAL concern?

Well, if your sample is not anhydrous, maybe not. Even if your acetone is anydrous you will then have some water in your solution, depending upon your sample's water content.

If your sample is anydrous and water can affect your column life (if the temperatures in your GC are low enough to allow the water to reside as a liquid on the column surface) then the water content of acetone is a REAL concern.

If the temperatures of the GC remain warm enough for any water injected to be in a vapor phase, and remain a vapor on the column, then water content of your dissolution solvent should not be a problem.

Of course, your sample may react with water when heated and that is another issue.

best wishes,

Rod