Chromatography Forum

I have some issues with Pesticide Stability when preparing a Pesticide Mix.
An I am not talking about years.
It seems that the Mix degrades in several days to weeks.

I read in some publication that adding some formic acid can increase the stability of pesticides in a Pesticide Standard mix.

Is there also a rule of thumb that some pesticides should not be mixed together?

Vor example I am preparing a mixture of the following pesticides
Acrinathrin
Aldrin
Captan
Coumaphos
Endrin
Fenitrothion
Flumethrin
tau-Fluvalinate
Tetradifon
Vinclozolin

Thank you for your help

I know captan degrades very fast, especially in basic condition.

I know captan degrades very fast, especially in basic condition.

Definitely Captan degrades fast, and also Endrin if there are any active sites on your glassware or in your system.

You may also want to check references and make sure none of these have problems with adhering to glass or plastic, depending on which you are using to store the solution in.

Hello!
We analyse 450 pesticides (multiresidues method).
All glassware is clean with Acetone, Hexane, Acetone
We dilute neat pesticide with acetone or toluene, sometimes, we use ultrasonic bath...all neat solution are store at -18c...
After, we mix the pesticide solution to create 3 mix pesticide solution, use brown glass bottle...each of them contains 150 pesticides
We have no problem with degradation....Captafol is not easy.
All mix standard solution is store at -18celcius

Thank you Rick

I will go for a mix of all as well and see where it is going

Hello
Rick can You mail me ? I have few questions about preparing stock and working standard solutions.
flutriafol@gmail.com