Reference Standard Storage

I have a reference standard that has to be stored under inert conditions. Can anyone give example of how they deal with this in their labs.

Reference Std to be store at 2-8°c at refrigerator

Moisture and oxygen in the atmosphere make the products unstable. Reference standards must be pure because they are used as standards for pharmaceutical products. So it is important to protect reference standards from moisture and air. Generally, Dry nitrogen gas is used as an inert gas in pharmaceuticals.

Please ensure the following aspects to protect the standard from the atmospheric conditions,

  • Fill up the standard material in a vial to the maximum so that headspace is kept as minimum as possible.
  • Flush out the air from the vial and replace it with Nitrogen gas (dry).
    -Seal the vial (Use a rubber plug and Aluminum cap to crimp it, similar to injection vial)
  • Every time you open the vial for using the standard material, repeat the above steps.
    -It is advisable to prepare the number of vials (as above) with minimum standard material for “Single use”. So that opening, closing & flushing the vial with Nitrogen multiple times can be avoided.
  • Keep the standard vils at 2 to 8 deg. C
    -Fpr single use the vials of smaller size should be selected.

How many vials should I have as a minimum?

The number of vials of that working standard to be prepared will depend upon the analytical frequency of that product every month/year (Number of batches manufactured in a month/year of that product).

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I give you an example, we generate 103 annual batches of a certain product. I would like to know how many vials I should enable to perform the analysis.

It may not be possible to prepare 103 vials of single-use (or 9 vials for one month). In this case, you can prepare 12 vials for one year (or 1 vial per month). Use one vial for about 9 batches analysis for one month. Every time you open & use the vial, please flush with dry nitrogen and seal it properly to ensure an inert atmosphere is maintained in the vial after every usage. After 1 month discard the content of the used vial. Maintain an adequate record of usage of working standard in the logbook meant for this purpose.

Thank you very much!