Hello,
The aforementioned solutions are to be used for the purpose of conducting soil enzyme assays. Because I will be using the solutions frequently in the coming weeks, I plan to store them. Is it possible to refrigerate them so they can last longer?
1. p-dimethylaminocinnamaldehyde solution will be made in ethanol
2. l-leucine b-naphthylamide hydrochloride solution will be made in deionized water
3. p-naphthylamine stock solution will be made in a mixture of deionized water and ethanol
Any help will be extremely appreciated!
Thank you very much for your time :)
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.
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