Chromatography Forum

Dear Chromatographers.

I have received some standard ampules indicating :

Diesel fuel.... must be stored at 2 - 8 °C

Arochlor 1232.... should be stored at 5 °C

Aromatic Hydrocarbon Std... must be stored 20 - 30 °C.

I use to break the ampule, then transfer into a vial and I store the vial in a freezer at around -2 to -4 °C, but now, I donk know what shoul I do?

Any suggestion would be appreciated.

bye.

I recommend asking the company that you purchased them from. Some analytes will precipitate out of solution at cold temperatures. Generally, careful sonication puts them back into solution.

Don, Thanks for your help.

We have stored ours in a refrigerator (reguardless of recommendation) for years with no problems. Freezing is overkill for anything except volatiles. Most of our semivols recommend room temp.

So, maybe storaging at low temperatures is not a good idea after all.

Interesting. We use a custom mix for a few of our 525 compounds. We buy 2 concentrations as one is used for a second source. The low concentration is to be stored in a freezer and the higher concentration in the fridge!!

Just a guess but, the larger PAHs may have a solubility problem at freezer temp and higher concentration.