Following

Do you have the SDS? It should give you a hint on stability in the solvents you mentioned.

As I recall you can store all of them in the refrigerator if they are made up in Class A amber volumetrics. Be sure to take them out >2 hours before use so they can adjust to room temperature.

In each analysis set use a previously tested soil as an internal control, so you can track when these solutions go bad.

Thank you so much for all the replies!

Udaya Jayasundara SDS for p-dimethylaminocinnamaldehyde and l-leucine b-naphthylamide indicates to store the compounds at -20C. P-naphthylamine can be stored in dry and well-ventilated place. How does that translate to their stability in solutions?

Bruce Neagle If I do not have amber volumetrics, can I wrap the normal glass volumetrics by silver foil? Also, according to your experience, approximately how long can they last?

@ Prashk

p-dimethylaminocinnamaldehyde and l-leucine b-naphthylamide indicates to store the compounds at -20C.

This means they are stable only in frozen condtions. There would be risk once you prepare the solutions with water and store in RF conditions. I suggest you to do a test for stability for both RF and FR condtions. Then you can see the most stable condition.

P-naphthylamine can be stored in dry and well-ventilated place.

This indicates it might have some affinity towards water. However, I believe for short term (max 8 hours), the samples may be good in RF conditions. Again, you got to try it.

As suggested, you could store in amber color vials or bottles (20-25 mL). If not, you may use aluminum fools but with care.

Think about the lighting in the room as well if you believe the light sensivity might degrade your compounds/solutions.

Prashank,

Yes, you can use tinfoil instead of amber volumetrics. Solutions, can last from 48 hours to a week.