Recomm. storage temperature ?

[Pepter]

Hello.
Can i storage analitical standard in freez if the certificate for this standard recomm. storage temp. : roomtemp.
Wont it be better to keep it in the lower temperature ?

[shaun78]

Generally yes, but strange things go happen.

I would suggest taking an aliquot of your material and place it in a freezer for a few weeks. Pull it out and make a standard with it. Also, make a standard out of the material stored at room temperature. Chromatograph them and check the responce factors of each. If both are similar, then you are safe (I would say similar is within 3.0% if this is an analytical assay).

I would also instruct everyone using the standard that they are to allow the frozen material to gradually reach room temperature before opening the container. You would be amazed at how many people skip that step when they are in a hurry ...

[H.Thomas]

Quoting from Document SANCO/10684/2009
METHOD VALIDATION AND QUALITY CONTROL PROCEDURES FOR PESTICIDE RESIDUES ANALYSIS IN FOOD AND FEED

Pesticide standards, calibration solutions, etc.

Identity, purity, and storage of standards

15. “Pureâ€