usually we give 2 months expiry for reagents for identifiation tests.
Normalilty solutions- one month expiry.
Examine a test sample by using freshly prepared solution and a solution prepared two months before.
Both the solutions should respond the same[Identification]. Document the same.
Normality solution : standardise the solution initially and after one month.
the variation of normality should not be away from +/-10%.
Bujji Reddy Kanchi.