Stability / expiry of reference standards

Discussions about methods and best practices across food quality, safety and authenticity testing.

2 posts Page 1 of 1
Dear colleagues
Assume you know that a substance is stable in stock solution and under controlled and defined storage conditions for a certain amount of time. This is tested and confirmed fulfilling all regulatory needs. Is it then reasonable to prepare a stock solution that expires later than the reference standard's expiry date?

In my opinion: Yes, because the expiry date from the CoA tells me that the quality of the reference standard is given until this date. So I can expect the solution of guaranteed quality to be stable for the known amount of time.

Looking forward to arguments supporting or proving wrong my argumentation. Or maybe there is official guidance to this question?

Best regards
bunnahabhain wrote:
Is it then reasonable to prepare a stock solution that expires later than the reference standard's expiry date?

We did. We documented stability of our in-house reference standard solutions stored in a refrigerator over like a 6-month interval. I'm sure there were times that the "expiration date" of the original reference material had passed.

In my opinion, many manufacturers began putting smaller stability times on their labels/certificates to get one to purchase fresh materials more often. At our company, stuff like sodium chloride, sodium sulfate, etc. had to be disposed of more frequently, and sometimes there were additional disposal costs.

Dummmm, stoooopid.....
2 posts Page 1 of 1

Who is online

In total there is 1 user online :: 0 registered, 0 hidden and 1 guest (based on users active over the past 5 minutes)
Most users ever online was 894 on Tue Dec 21, 2021 5:59 pm

Users browsing this forum: No registered users and 1 guest

Latest Blog Posts from Separation Science

Separation Science offers free learning from the experts covering methods, applications, webinars, eSeminars, videos, tutorials for users of liquid chromatography, gas chromatography, mass spectrometry, sample preparation and related analytical techniques.

Subscribe to our eNewsletter with daily, weekly or monthly updates: Food, Environmental, (Bio)Pharmaceutical, Bioclinical, Liquid Chromatography, Gas Chromatography and Mass Spectrometry.

Liquid Chromatography

Gas Chromatography

Mass Spectrometry