Chromatography Forum

What is the recommended storage (room temp, or refrigerated) for trifluoroacetic acid in 1 mL ampoules? Some have said room temp is adequate, while others say the ampoules should be stored refrigerated.

FLuke recommends -20°C storage.

I would store in the dark and as cool as convenient.

best wishes,

Rod

We buy ours from Sigma and keep them in RT.

We keep ours at RT, in the dark. We use a lot, so we usually get 100mL bottles.

We usually keep ours in the dark at RT as well.

I have a 500 mL bottle of Pierce sequanal-grade TFA that is at least 6 years old and still good. Kept at room temperature. I have mentioned before that some vendors use incompatible materials in their bottle caps. Fluka is one example; their product is excellent until you open it the second time and find brown gunk in the cap.

In our lab we have had much better luck since we swithed over to the 1 mL ampules. It prevents excessive exposure to oxygen, prior to use.

Everything to gain and nothing to lose, in my view.

Adam

In our lab we have had much better luck since we swithed over to the 1 mL ampules. It prevents excessive exposure to oxygen, prior to use.

Everything to gain and nothing to lose, in my view.

Adam

Except $$$ (It's pretty pricey 1mL at a time).

I stored mine ( 100ml ) in the fridge ( 3C ) till I first opened it. It takes about a year to use it, and I've seen no issues, even though some bottles were 4 years past their recommended use by date. I usually decant about 30 mL out into another bottle and work from that.

I agree with Mark Tracy about some containers being unsuitable, but using an old TFA bottle as the working container works fine for me. When available, I purged the working container with N2, but that probably was more to see the impressive white fumes . Doesn't seem necessary if opening time is brief.

It's interesting to consider suppliers' expiry policies, Romil HPLC has 2 years life from manufacture, and only 3 months after opening. Fisher HPLC has no life ( on bottle ), storage at <30C, and 3 years after opening.

1 mL ampoules would mean that I'd be storing or tossing some, as I usually only make up 500 ml and typically at 0.05%. Depends on use, but currently 100 ml is much cheaper here. As always, price here depends on use, if lots of people use ampoules, their price ccould drop below the special import cost of occassional 100 ml containers. It's probably worth checking out the comparable prices in each user's location.

Bruce Hamilton