1.0 PURPOSE:– To describe the procedure for determination of shelf life of solution in laboratory.

 

2.0 SCOPE:- This SOP is applicable for determination of shelf life of solution in laboratory.

 

3.0 RESPONSIBILITY:-  Technical Manager/Quality Manager/QC Chemist

 

4.0 PROCEDURE: –

 

4.1 VOLUMETRIC SOLUTIONS: –

 

4.1.1 Physically verify the solution, if it is not clear and sedimentation/precipitation occur    discard the solution immediately.

 

4.1.2 Prepare the volumetric solution and allow standing. After 24 hours determine the molarity of solution in triplicate calculating the mean of the results and continue the determination at an interval of 5 days for 30 days. Determine the RSD of all 5 values. If RSD of all 6 values remains less than 1.0 shelf life of solution should be assigned in 30 days otherwise RSD shall be calculated with first 03 values and shelf life should be assigned in 15 days. If the RSD of first four values remains more than 1.0, RSD shall be calculated with first three values and shelf life of the solution should be assigned accordingly.

 

4.2 REAGENT SOLUTIONS: –

4.2.1 Physically verify the solution, if it is not clear and sedimentation/precipitation occur    discard the solution immediately.

 

4.2.2 Reagents Solutions, those are used in analysis as reactants and molarity is not calculated. These are validated on their performance. The Performance of these solutions is checked at an interval of 15 day for 1 month and reagent must be checked before use.
4.3 BUFFER SOLUTIONS: –

4.3.1 Physically verify the solution, if it is not clear and sedimentation/precipitation occur    discard the solution immediately.

 

4.3.2 Buffer is generally used for calibration of pH meters. pH of buffer solutions may change due to chemical degradation. The shelf life of buffer solutions must not be assigned for more than 15 days and must be checked before use.