HI THERE
Could anyone tell me how many times a Working Standard could be opened.
my local authority mentioned 3 times opening per vial. However, they also asked us to study the shelf-life of the working standard (stored in a vial) by the frequency of vial opening.
they also advised that the working standard may packed in small amount sufficient for 3-5 times usage.
[quote=choy77]my local authority mentioned 3 times opening per vial. However, they also asked us to study the shelf-life of the working standard (stored in a vial) by the frequency of vial opening.
They also advised that the working standard may packed in small amount sufficient for 3-5 times usage.[/quote]
very good idea
humayun
it depend on the nature of the substances. unstable or very hygroscopic substances should not be stored after the container was opened.
beside how many times it could be re-opened, we should propose how long time the standards could be stored after the first opening.
a controlled environment glovebox could be used when handling reference standard. the glovebox could keep the humidity as low as possible and inert gas could be used to remove oxygen within it.
It depends on the nature of the standard.If it is hygroscopic open one time only