08-08-04 03:07
No 524229
Vinegar/acetic acid (any % H2O) is placed into a distillation setup and castor oil is added to the soln.
The mixture is rotationally stirred to prevent the oil layer from being broken.
Pure acetic acid will distill over as glacial acetic acid is miscible with castor oil, however, water is not, therefore differentiating the contents via miscibility. (Consider using a drying tube to make sure it's dry. Water in the air above the tube may slightly reduce the purity of the acetic acid.)
Btw, castor oil is also miscible with alcohol, so this technique can be applied with ethanol to get anhydrous ethanol.
Benefits: Cheap. Easy. OTC. No fancy gear needed. If a stirring apparatus cannot be implemented into the oil, one could mix the oil and vinegar/AA, seperate the oil and distill the AA out of the oil directly. Anyone care to find faults?
(Chief Bee)
08-08-04 05:41
No 524239
What makes you think that a lower-boiling component of a two-phase mixture wouldn't distill before a higher-boiling component?
If you put dichloromethane and water in a flask, don't you think the DCM would distill over before the water even if the water layer is on top?
The Hive - Clandestine Chemists Without Borders
(Hive Addict)
08-08-04 09:20
No 524256
Reminds me of steam distilling!
fear fear hate hate
(Hive Bee)
08-08-04 23:23
No 524379
Rhodium, it has nothing to do with the -Placement- of the layers it has to do with miscibility of the components.
For starters, simply adding castor oil and removing that layer and distilling should suffice.
Second of all, one could get a cooking pot and insert an element into the pot so that it is only heating up the oil layer. Acetic acid will migrate and be distilled out, leaving the water, colder than the oil layer, behind.
(Chief Bee)
08-08-04 23:31
No 524381
Then, reading the msds of castor oil and finding its also miscible with castor oil, the same properties will exhibit.
Huh?
The Hive - Clandestine Chemists Without Borders
(Hive Bee)
08-08-04 23:37
No 524382
Err, i meant acetic acid.
I see where you're coming from, that the acetic acid wont distill easily because its BP is higher then that of water. But by moving the heat source to the oil layer, -or-easier still, dumping castor oil into vinegar/acetic acid, then stirring so that some of it becomes miscible then removing the castor oil/acetic acid layer and distilling that layer should yeild castor oil in the first flask and GAA in the second flask..
(Hive Bee)
08-09-04 02:04
No 524400
Extracting acetic acid from dilluted solutions (the most concentrated vinegar in my country is 9%) is very unefficient even with solvents that have a reasonably good partition coeficient (like ethylacetate) and requires a continous extraction. I seriously doubt that castor oil or any other "oil" would take up a useful amount of acetic acid, but you are free to try and tell as all about it. Hower you can forget the idea of distiling AA from a two phase system like you described it. The oil is not going to hold back the water wapors - the water at the phase boundary would start to boil as the oil would reach temperatures above 130°C that would be needed to evaporate the small concentrations of AA and water from its phase. There is no way to keep the water bellow its b.p. as liquids are good heat conductors and even bellow 100°C the wapors would still apreciably diffuse trough the imobile oil layer.
“The real drug-problem is that we need more and better drugs.” – J. Ott
(Hive Bee)
08-10-04 00:28
No 524587
Nicodem as soon as SWIM gets some castor oil SWIM will attempt it. As far as SWIM sees, as the msds states it's miscible with AA and not water, then adding castor oil should find an equilibrium of miscibility with the oil and water. Eg, if you have X amount of AA in water, and you add the same amount of oil, you should get half of X per layer. Yes?
(Hive Bee)
08-10-04 08:51
No 524640
Eg, if you have X amount of AA in water, and you add the same amount of oil, you should get half of X per layer. Yes?
Where did you get such an idea from? Like I told you the distribution of X in both solvents depend on the partition coeficient (=distribution coeficient) of the particular biphasic system. Read and see the table in http://www.cheresources.com/extraction.s
Anyway, are you saying that where you live you can't buy acetic acid? Not even the 80% AA? Incredible.
“The real drug-problem is that we need more and better drugs.” – J. Ott