storage standar vials

[pueblito]

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.

[Don Shelly]

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.

[pueblito]

Don, Thanks for your help.

[twranger]

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.

[pueblito]

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

[Bigbear]

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!!

[Steve Reimer]

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