Don, what solvent would use for a cleaner evaporation. I don’t have The app for MSDS.
Thant you for the gentle critique. Johannes
I don’t have enough information about what your protocol is to guess at a solvent system.
I was recommended xylenes by an histology Prof and her Tech. I tried it with Potentila and it worked well.
- Put petals of yellows In a Teflon homogenator they have to be fresh.
- Grind and add xylenes in small quantity until the petals start to loose colour and start to degrade. Make sure that the colour is very yellow
- Pipet a small amount, quarter size, onto cellulose chromatography paper. Let this dry and then apply again on the same spot do this over a few time so the yellow becomes dark.
- Do the topaz Jewel in the Teflon with water instead there is no colour
- Apply some drops of this solution on the yellow.
- Let the reaction occur be careful not to let it dry out I have a chamber for that.
- Look for whitening of the last white drop
Please critique at will
I feel limited in my ability to discuss. I will probably not use this technic again. but Please be understanding that this technology is proprietary and I do not want it to reveal the data that I received. So please be understanding.
Apply some drops of this solution on the yellow
That’s brilliant - an easy assay for the carotenoid degradative (dioxygenase?) enzymes.
About solvents. If you dig round in very old literature on carotenoid analysis (such as vitamin A and pro-vitamin A) you’ll find that they used a very non-polar solvent to extract them from things. Then sorbed them to magnesium oxide (Seasorb) with diatomaceous earth to improve flow properties of a column packed full. To separate different ones, elute with same solvent, increasing proportions of a more polar solvent such as acetone at 5 %, 10 %, 15 %. I got this from a retiring faculty member in the late 1970s.
The solvent s went by various names such as ligroin, Stoddard solvent (non-chlorinated one used by dry cleaners), Skellysolve, heptanes, hexanes. I would rather not use xylenes as they are too close to benzene and toluene. I’ve had decent results for some purposes with odorless paint thinner. For your purposes, the key is that it needs to evaporate before you dare apply an enzyme. Kerosene would take forever (almost), hexanes are a little too volatile to feel safe unless you have really good ventilation. Stoddard worked OK in dry cleaners, didn’t smell up the clothes too much and didn’t blow people up very often.
My (1970’s) organic professor distinguished ligroin as being a distinct a mix of mostly linear alkanes in the c6-10 range. Petroleum ether is similar but more volatile having a lighter fraction.
At one time you could buy white gas, a similar mix, at the filling station which was a useful fuel for blow torches and vintage engines. Today the only thing that comes close is Coleman lantern fuel. Don’t smoke and use it outdoors far away from sparks, flames and UV lamps.
Dumb question but how do you get coleman fuel out of the tank safely?
How dangerous is xylenes understand that I am using only .3 ml at a time.
I believe white gas is what we call unleaded now (the kind without ethanol added). I remember having to get that for our lawnmower as a kid- Amoco brand. More recently the aromatic fraction has been reduced, things like benzene , toluene, xylenes.
The xylenes are not toxic unless inhaled a lot, or directly ingested while siphoning or equivalent, and not carcinogenic like benzene. They are less volatile also, but still boil off readily enough. That is probably important in the enzyme assays. You don’t want to wait a week for kerosene to mostly evaporate. Paint thinner (mineral spirits) may be satisfactory. Odorless means no benzene, toluene, xylene. I think you may find on the MSDS page something about the amount of residual (low volatility),and certainly the boiling point etc.
I know that there are 6yrs since I posted about Rosa beggeriana, but things change. I now use a
Rosa beggeriana)x((Martin Frobisher)x (Rosa rugosa var alba x R. woodsii))