to determine the length of life of a product chemical after opening

We studied the stability (its reactivity vis à vis the parameter such as extrinsic, temperature, contact with air, moisture, contamination etc) either makes the identity test of degradation, deterioration all ca serves aa check if the compound is maintained in the prealablment established specification

"THF, potassium (or sodium) carbonate naphthylamine, sodium benzoate, and sodium hypochlorite etc"

Thank you in advance?