Sciencemadness Discussion Board

Separating waxy crap from methylene chloride

Quince - 6-12-2006 at 07:44

After distillation through a vigreux into ice water, I realized that even though I did not let the head go above 40*C, a good deal of the gelling agent/thickener came over... after some hardcore stirring with the water, some of it separates from the methylene chloride, forming a sticky white mess. Seems suspiciously similar to paraffin (and the brush scrubbed it off the glassware easily without solvents or pirahna solution), but I don't understand how it could have come over at such a low temperature...could it form something akin to an azeotrope? In that case even fractioning would not separate all of it out. I removed the water and floating wax bubbles with a separatory funnel and swirled in some sulfuric acid. It became yellow and gathered up some more wax. Still not gone... Another washing with ice water. More wax comes out. What the fuck? How do I finish this process? I don't have any other source for methylene chloride, as the pure one sold as acrylic solvent is five to ten times more expensive.

[Edited on 6-12-2006 by Quince]

solo - 6-12-2006 at 09:33

Just a thought......how about putting it in the freezer and let the wax harden and just peel off the wax and recover your wax -free dichloromethane................solo

XxDaTxX - 6-12-2006 at 09:38

I can think of better reagents to do this, but since it seems you would probably have limited or no access to them.

Steam distill your DCM/wax. You should end up with fairly pure DCM/H20 in your reciever.

As for the wax left behind in your distillation flask, boil some heptane rinse your flask with it, and while you're at it pull it through your clogged fritted funnel.

Heptane can be had from most car starter sprays. It is the higher boiling fraction. I'm sure you would probably end up keeping the lower boiling fraction as well.

Make sure to do the heptane/ether seperation first in a clean distillation setup, since waxes are known to sparingly dissolve in both.

garage chemist - 6-12-2006 at 11:19

How about buying pure DCM instead of that crap that obviously cannot be separated into its constituents?
And no, I don't mean the overpriced acrylic solvent.
I mean DCM.

And don't even start complaining that you can't find a supplier. Maybe no supplier will ship to individuals, but nearly all suppliers will ship to pharmacies.

chromium - 6-12-2006 at 14:27

I do not know if your mixture has azeotrope or not but separating substances with fractional distillation is not always fast and easy. I also do not know how you did this process but to get good separation one should distill very slowly. Most of liquid must flow back from column to boiling flask and if you get output of one drop per secund you will probably get rather weak separation (at least if your column is not >60cm hempel wth HQ filling).

Shortly, you may want distill it with much higher reflux ratio, collecting 10 drops per minute or even less. This may or may not help in your case. What i know for sure is that slower distilation (even if no column is used) gives usually much better separation than fast bulk distillation.


[Edited on 6-12-2006 by chromium]

Quince - 6-12-2006 at 23:52

Quote:
Originally posted by garage chemist
nearly all suppliers will ship to pharmacies.

Not in Canada. I've asked several pharmacies here for a variety of substances, and the only thing I managed to get was citric acid. And for DCM specifically, what possible reason could I give the pharmacy for wanting it?

[Edited on 7-12-2006 by Quince]

Quince - 7-12-2006 at 00:02

Quote:
Originally posted by XxDaTxX
Steam distill your DCM/wax. You should end up with fairly pure DCM/H20 in your reciever.

Is this what you mean?
http://upload.wikimedia.org/wikipedia/en/3/35/Steam_Distilla...
I don't know much about this procedure. So this works even if the DCM is fairly insoluble in water? What temperatures would be appropriate for the flask containing the impure DCM?

BTW, I managed to remove the wax from the flask by adding a bit of lye solution which turned it all white and less sticky, and then came off with just light scrubbing with a standard brush. The funnel I cleaned with piranha solution.

[Edited on 7-12-2006 by Quince]

Quince - 7-12-2006 at 00:32

Quote:
Originally posted by chromium
I also do not know how you did this process but to get good separation one should distill very slowly. Most of liquid must flow back from column to boiling flask and if you get output of one drop per secund you will probably get rather weak separation (at least if your column is not >60cm hempel wth HQ filling).

I distilled 800 mL over about two hours, but the problem is not only do I have just a simple Vigreux instead of a proper fractioning column, but I had no way to cool the column so I ran very low heat on the flask, resulting in not just slow distillation but also very slow reflux back into the flask. The problem is the low 40*C temperature. Even a fan doesn't help much. Does anyone have a good way to cool the Vigreux? Doing this outside has the advantage that the air is cold. Doing this outside has the disadvantage that my skinny body can't handle the cold. Any other way?

Also, I want to add that I've accidentally become a guinea pig on the effects of inhaling large amounts of DCM, and I'll say other than a very short-lived, mild vertigo, there's no lingering malaise.

[Edited on 7-12-2006 by Quince]

Quince - 7-12-2006 at 03:59

Quote:
Originally posted by solo
Just a thought......how about putting it in the freezer and let the wax harden and just peel off the wax and recover your wax -free dichloromethane................solo

OK, I froze it, but now it just looks milky in color, nothing separating out...

turd - 7-12-2006 at 05:40

Quote:
Originally posted by XxDaTxX
Steam distill your DCM/wax. You should end up with fairly pure DCM/H20 in your reciever.

And what, pray tell, is the point of steam distilling something with a bp < 100°C?

Quince - 7-12-2006 at 06:28

Steam distillation doesn't necessarily reach 100*C as the mixture can have a lower boiling point. The water vapor can remain vapor at much lower temperatures.

[Edited on 7-12-2006 by Quince]

unionised - 7-12-2006 at 11:38

There may be a point to steam distilling things that boil below 100C but I don't see any point to steam distilling DCM.
To a good aproximation what will happen is that steam will condense to water in the distilling flask and the DCM will boil. This is just a complicated way of heating the flask.
I find it hard to believe that any wax distilled over; fobbing or spraying seem much more likely to me.

XxDaTxX - 7-12-2006 at 12:23

Quote:
Originally posted by unionised
There may be a point to steam distilling things that boil below 100C but I don't see any point to steam distilling DCM.
To a good aproximation what will happen is that steam will condense to water in the distilling flask and the DCM will boil. This is just a complicated way of heating the flask.
I find it hard to believe that any wax distilled over; fobbing or spraying seem much more likely to me.


Your oversimplification holds true in many cases depending on the components being distilled, but multicomponent systems are are far from the "ideal" model of distillation you have in mind if their constituents are extremely dissimilar. I will spare you the ramblings about Raoult's/Dalton's law and the magnificent 3D vapor pressure graphs that follow. Just know that it works.

Steam distillation using an external source of steam may not be necessary. Steam distillation by merely adding water to your flask, heating, and distilling is common practice. Some sort of mixing should be employed, presumably a magnetic stirrer. Please don't ask why you have to mix it. Its finals week and these engineering classes are kicking my arse.

But yes, an external source of steam would be most efficient as it would increase the water vapor pressure inside the distillation column.

Alternatively if you have an addition funnel you can drip your methylene chloride/wax solution into a moderately heated flask of water w/mag stirring and collect the distillate. But it would not have a higher efficiency than the previously mentioned method.

[Edited on 7-12-2006 by XxDaTxX]

Quince - 7-12-2006 at 14:54

What's fobbing?

Also, there was no spray as all was caught by the Vigreux, whereas the stuff was in pretty heavy amounts. I found it strange that, although the head never exceeded 40*C, the flask itself was quite hot when I pulled it out, and it wasn't just the glass.

I may try the steam distillation. I can't use a rubber cork for the incoming steam tube as the DCM will destroy it, but I'll try to squeeze the one I have through the thermometer adapter; unfortunately, then I won't be able to use the thermometer...

[Edited on 7-12-2006 by Quince]

turd - 8-12-2006 at 01:37

Good luck. And please post a video.

Quince - 8-12-2006 at 02:54

LOL, I don't even have a digital camera to take stills. I occasionally scan my film photos at university. I'll buy something when I get a job.

XxDaTxX - 8-12-2006 at 08:12

I have to add that traditionally one would chill and centrifuge first, but it seems you chilled and filtered already, and are still getting waxes, and I assume you have no access to a centrifuge so steam away....

Use a pipet, and make sure your water flask has a stopcock or something to vent/control flow rate to your DCM/wax flask.

Hvap of DCM:water is something like 3:4 so start with the vent open, heat, then clamp down on vent to control steam flow into the DCM.

[Edited on 8-12-2006 by XxDaTxX]

Quince - 9-12-2006 at 08:49

Do I need to chill the DCM flask during the process to prevent it from boiling? I'm not sure when you talk about control, what I'm watching for that I would adjust when I see it.

XxDaTxX - 9-12-2006 at 15:11

In steam distillations one can usually crank up the heat on the generator to achieve fairly high velocities through a condenser, however using a refrigerant like (DCM) changes that quite extensively.

For 1 mol of DCM that you want to vaporize, you only need .75 mol of water, assuming no thermal losses.

This translates into 85g of DCM for every 13.5g of water condensed. You see what I mean now? How good of a condenser do you have? =]

Unless you have a good chiller, you should take it slow. Generator /w two outlets, one to a stopcock/adjustable "vent" ... and the other to your still. Use a pipet, or something with an appropriately small diameter tip or else you will not be able to maintain low steam flow. Don't ask me why, its too long of an answer.

As for chilling the DCM, the thermal losses would induce the same effect that an adjustable vent would do. Either that or just turn down the generator. If you have a problem with patience then yes, keep an ice bath handy, while your at it pick up a scuba tank. =]

[Edited on 9-12-2006 by XxDaTxX]

unionised - 10-12-2006 at 02:47

This is a slightly weird steam distillation. Normally we talk about steam distilling something relatively involatile like nitrobenzene. The large volume of steam carries over a small amount of nitrobenzene vapour at a temperature (just below 100C) well below the boiling point of nitrobenzene (211C).
In this case we are talking about the very volatile DCM. It would be better to think of this as dichloromethane vapour- distilling water. The DCM vapour will carry over a little water and lets you distill water at the azeotrope temperature for mixture.
Having the dcm vapour carry a little water with it at a slightly lower temperature than just distilling it doesn't seemlikly to serve any real purpose.
You still need to separate the water later- not difficult, but why bother?

Quince - 10-12-2006 at 03:05

Is it safe for the DCM to add lye? I find that when I was cleaning the wax from the flasks, lye turned it it from a thick, greasy, clear gel into an almost solid white, slimy-instead-of-greasy plastic-like stuff. I'm thinking it may precipitate it out of the DCM, and I can just filter it out and then wash the DCM with water to remove any soapy residue if that's what's the lye is doing.

[Edited on 10-12-2006 by Quince]

Ozone - 10-12-2006 at 08:11

The alkali can abstract the protons from the CH2Cl2 leading to dichlorocarbene (:CCl2).

Good luck,

O3

XxDaTxX - 10-12-2006 at 08:12

Quote:
Originally posted by unionised
This is a slightly weird steam distillation. Normally we talk about steam distilling something relatively involatile like nitrobenzene. The large volume of steam carries over a small amount of nitrobenzene vapour at a temperature (just below 100C) well below the boiling point of nitrobenzene (211C).
In this case we are talking about the very volatile DCM. It would be better to think of this as dichloromethane vapour- distilling water. The DCM vapour will carry over a little water and lets you distill water at the azeotrope temperature for mixture.
Having the dcm vapour carry a little water with it at a slightly lower temperature than just distilling it doesn't seemlikly to serve any real purpose.
You still need to separate the water later- not difficult, but why bother?


There is no DCM/Water azeotrope. Technically it is more though of as "Stripping" DCM away from high boiling components, as opposed to "vaporizing" or traditional "distillation". But I don't want to get into those technicalities. It can be done correctly the way I said it, or one can use heated air into a DCM:Wax:Water mixture. Which is infact better as far as controlling the rate of condensate, but requires one to have a source of said air ~70oC or so.

Quote:
Originally posted by Quince
Is it safe for the DCM to add lye? I find that when I was cleaning the wax from the flasks, lye turned it it from a thick, greasy, clear gel into an almost solid white, slimy-instead-of-greasy plastic-like stuff. I'm thinking it may precipitate it out of the DCM, and I can just filter it out and then wash the DCM with water to remove any soapy residue if that's what's the lye is doing.


Some n-alkanes are cheap solvents, whether you have access to them I am not sure. Heat some it in your flask, swirl, decant, repeat. Rinse again with water, then tell yourself "I will never again extract essential oils with DCM. I will do as XxDaTxX says and steam distill before partitioning in DCM."

[Edited on 10-12-2006 by XxDaTxX]

Nicodem - 10-12-2006 at 08:28

Quote:
Originally posted by XxDaTxX
There is no DCM/Water azeotrope.

All immiscible liquids distill an azeotrope mixture since such mixtures boil at the sum of the partial pressures of the two liquids. Hence the boiling point of such mixtures are always lower than the boiling point of the most volatile component. According to Table of Azeotropes and Nonazeotropes (Horsley, 1947 – available for download somewhere on this forum) the CH2Cl2/H2O azeotrope boils at 38.1°C and contains 1.5% water and 98.5% dichloromethane. The author of the table refers to Bakowski and Treszczanouicz, Przemsyl. Chem., 22, 211 as his source.

XxDaTxX - 10-12-2006 at 08:41

Quote:
Originally posted by Nicodem
Quote:
Originally posted by XxDaTxX
There is no DCM/Water azeotrope.

All immiscible liquids distill an azeotrope mixture since such mixtures boil at the sum of the partial pressures of the two liquids. Hence the boiling point of such mixtures are always lower than the boiling point of the most volatile component. According to Table of Azeotropes and Nonazeotropes (Horsley, 1947 – available for download somewhere on this forum) the CH2Cl2/H2O azeotrope boils at 38.1°C and contains 1.5% water and 98.5% dichloromethane. The author of the table refers to Bakowski and Treszczanouicz, Przemsyl. Chem., 22, 211 as his source.


If you want to get technical, then yes, but when one speaks of azeotropes it is usually in respect to an appreciable ratio of components. Do you really think I assume a partial pressure of 0 for water. Heheheh.

unionised - 10-12-2006 at 09:10

I think ozone has mixed up DCM with chloroform.
BTW, XxDaTxX ,
"DMSO is a cheap solvent that you must have access to. Heat some it in your flask, swirl, decant, repeat. Rinse again with water, then tell yourself "I will never again extract essential oils with DCM. I will do as XxDaTxX says and steam distill before partitioning in DCM."
"
Why?
Quince seems to have cleaned the glassware without using DMSO (and I would have tried caustic first, then white spirit; DMSO isn't that cheap or accessible it's also a poor solvent for saturated hydrocarbons and a lot of waxes fall into that group). So far as I can judge he's now after cleaning up the DCM.

Washing the DCM with caustic to remove the waxy stuff might work but alkaline extractions often give messy emulsions.

For the original extraction of the oils, in general it's better to steam distill out essential oils, not least because water's a very cheap solvent. OTOH the oils always come over with a lot of water and you will improve the yeild if, in addition to simply separating the oil from the water by density, you also extract the water layer with a solvent to remove such oil as is dissolved in it. DCM is quite a good choice for this as it's easy to evaporate off again later.

Oh, also, I wouldn't have refered to the DCM/water azeotrope if it didn't exist and I'm reasonably familliar with the idea of steam stripping for solvent revovery. I still think it's a weird steam distillation.

I still want to know what this thickening agent/wax that distills below 40C is. Whatever it might be, if it distills over with straight DCM at 39.75C I suspect it will distill over with the water/ DCM azeotrope at 38.1C so I don't see any advantage to steam distillation to clean up the solvent (unless the stuff happens to react with water).

XxDaTxX - 10-12-2006 at 09:21

Quote:
Originally posted by unionised
I think ozone has mixed up DCM with chloroform.
BTW, XxDaTxX ,
"DMSO is a cheap solvent that you must have access to. Heat some it in your flask, swirl, decant, repeat. Rinse again with water, then tell yourself "I will never again extract essential oils with DCM. I will do as XxDaTxX says and steam distill before partitioning in DCM."
"
Why?
Quince seems to have cleaned the glassware without using DMSO (and I would have tried caustic first, then white spirit; DMSO isn't that cheap or accessible it's also a poor solvent for saturated hydrocarbons and a lot of waxes fall into that group). So far as I can judge he's now after cleaning up the DCM.

Washing the DCM with caustic to remove the waxy stuff might work but alkaline extractions often give messy emulsions.

For the original extraction of the oils, in general it's better to steam distill out essential oils, not least because water's a very cheap solvent. OTOH the oils always come over with a lot of water and you will improve the yeild if, in addition to simply separating the oil from the water by density, you also extract the water layer with a solvent to remove such oil as is dissolved in it. DCM is quite a good choice for this as it's easy to evaporate off again later.

Oh, also, I wouldn't have refered to the DCM/water azeotrope if it didn't exist and I'm reasonably familliar with the idea of steam stripping for solvent revovery. I still think it's a weird steam distillation.

I still want to know what this thickening agent/wax that distills below 40C is. Whatever it might be, if it distills over with straight DCM at 39.75C I suspect it will distill over with the water/ DCM azeotrope at 38.1C so I don't see any advantage to steam distillation to clean up the solvent (unless the stuff happens to react with water).


Bad suggestion. In a lab n-alkanes works wonders on waxes. Certain chain lengths are particularly cheap. However, it seems he has limited access to these sorts of things.

... as for the steam stripping .... try it if you like. It works in industrial applications, and thats good enough for me.

Ozone - 10-12-2006 at 12:12

Errata!

Thanks Unionised! That is correct, CHCl3 will easily give dichlorocarbene (see Hoffmann Isonitrile synthesis); DCM cannot (with this base) do this. Stronger bases, however, such as Na, will form carbene from DCM; these reactions have a tendency to explode.

O3

unionised - 10-12-2006 at 13:46

I must be missing something here. XxDaTxX, do you really think it's easier to get hold of DMSO than gasoline/ kerosene/ white spirit/ lighter fluid?

My guess is that, wherever Quince bought the DCM+ waxy stuff from stocked some sort of cheap hydrocabon solvent labeled as "turps substitute" or some such. DMSO isn't something I have seen for sale OTC except on eBay.
(Quince I realise that it isn't relevant any more because you cleaned the flask with caustic, but I'd be grateful if you would let us know whether you would find it easier/ cheaper to get DMSO than gasoline or some such.)
I'd still like someone to explain to me why steam distillation will work any better than ordinary distillation for removing waxy stuff from DCM (unless the stuff reacts with water which I think is unlikely. I'm also open to wild speculation about the nature of this distillable wax. Solids with significant vapour pressures at 40C are thin on the ground- I'd like to know more.

Quince - 10-12-2006 at 19:30

Quote:
Originally posted by XxDaTxX
partitioning in DCM.

Well that's the thing. I've never taken a university chemistry class, so I simply have no idea how to do that, and likely do not have the hardware for it. On the other hand, I have a Gregar extractor that a retired blower made for me cheaply, so I use what I have and did solvent extraction.

Is there any test I can do on the waxy stuff to try to find out hat it is? I'm not even certain it's wax; it appears to be a bit like a polymer after the caustic acts on it.

XxDaTxX - 10-12-2006 at 20:24

Quote:
Originally posted by Quince
Quote:
Originally posted by XxDaTxX
partitioning in DCM.

Well that's the thing. I've never taken a university chemistry class, so I simply have no idea how to do that, and likely do not have the hardware for it. On the other hand, I have a Gregar extractor that a retired blower made for me cheaply, so I use what I have and did solvent extraction.

Is there any test I can do on the waxy stuff to try to find out hat it is? I'm not even certain it's wax; it appears to be a bit like a polymer after the caustic acts on it.


Add water/essential oil mix obtained by steam distillation into a seperatory funnel (or any container that dosent dissolve in DCM) and add DCM. Shake and seperate.

Alternatively, you should go buy a "basic organic chemistry techniques" book off ebay/amazon ..... before you explode your seperatory funnel by adding to freshly collected distillate and not venting.

Quince - 10-12-2006 at 20:50

I take it the oils mostly end up in the DCM portion? Then I can simply distill off the DCM and no further processing?

[Edited on 11-12-2006 by Quince]

XxDaTxX - 10-12-2006 at 21:01

Quote:
Originally posted by Quince
I take it the oils mostly end up in the DCM portion? Then I can simply distill off the DCM and no further processing?

[Edited on 11-12-2006 by Quince]


Yes.

Quote:
Originally posted by unionised
I must be missing something here. XxDaTxX, do you really think it's easier to get hold of DMSO than gasoline/ kerosene/ white spirit/ lighter fluid?

My guess is that, wherever Quince bought the DCM+ waxy stuff from stocked some sort of cheap hydrocabon solvent labeled as "turps substitute" or some such. DMSO isn't something I have seen for sale OTC except on eBay.
(Quince I realise that it isn't relevant any more because you cleaned the flask with caustic, but I'd be grateful if you would let us know whether you would find it easier/ cheaper to get DMSO than gasoline or some such.)
I'd still like someone to explain to me why steam distillation will work any better than ordinary distillation for removing waxy stuff from DCM (unless the stuff reacts with water which I think is unlikely. I'm also open to wild speculation about the nature of this distillable wax. Solids with significant vapour pressures at 40C are thin on the ground- I'd like to know more.


I have seen DMSO available from small pharmacies before .... although I thankfully have never had the need to purchase it myself.

I retracted my statement about DMSO dissolving wax ... not that it doesn't but because I cannot say with any degree of certainty because I haven't tried it. It was a shot in the dark for a, personally, available solvent that has worked in other situations for myself. I have, as of late, had much success using boiling DMSO to clean out flasks with polymerized gunk that a/b baths wouldn't take out.

I usually leave the chromic to the undergrads who have been bad. Im .... uhh .... allergic to the stuff ..... yeah thats it. =P

[Edited on 11-12-2006 by XxDaTxX]

Quince - 10-12-2006 at 22:46

Steam distillation is underway. Hopefully it will work.

One thing is I don't know when I should stop. Since I'm using the thermometer hole for the steam injection tube, I can't stick a thermometer in the flask...

[Edit:] Er, deposits are starting to grow at the end of the condenser spout...WTF?!

Looks like ice

[Edited on 11-12-2006 by Quince]

XxDaTxX - 10-12-2006 at 23:15

Quote:
Originally posted by Quince
Steam distillation is underway. Hopefully it will work.

One thing is I don't know when I should stop. Since I'm using the thermometer hole for the steam injection tube, I can't stick a thermometer in the flask...

[Edit:] Er, deposits are starting to grow at the end of the condenser spout...WTF?!

[Edited on 11-12-2006 by Quince]


You added some water to your DCM/wax first right?

Hold on ..... you are trying to purify waxes that came over when doing an extraction right? You aren't trying to purify some kind of paint/stripper methylene chloride mixture you purchased from an orange warehouse right?

[Edited on 11-12-2006 by XxDaTxX]

Quince - 10-12-2006 at 23:33

If you thought it was the former rather than the latter, you're the only one in this thread. Very first sentence in the very first post: "gelling agent/thickener". Another clue should have been garage chemist's post: "How about buying pure DCM instead of that crap that obviously cannot be separated into its constituents?"

[Edited on 11-12-2006 by Quince]

Quince - 11-12-2006 at 01:50

Worked, but yield wasn't good. Quite a bit of the DCM evaporated, even though I was doing everything outside in the cold and the condenser had 5*C water running through it. In the end the amount of wax was pretty small (a few percent), for all the mess it made.

[Edited on 11-12-2006 by Quince]

XxDaTxX - 11-12-2006 at 08:02

Quote:
Originally posted by Quince
Worked, but yield wasn't good. Quite a bit of the DCM evaporated, even though I was doing everything outside in the cold and the condenser had 5*C water running through it. In the end the amount of wax was pretty small (a few percent), for all the mess it made.

[Edited on 11-12-2006 by Quince]


General procedure is centrifugation in low temps, followed by steam distillation. Like i said, it has its pitfalls as far as condensing the vapor and controlling the feed rate, but with no access to a centrifuge, and limited access to reagents, thats probably the best you can do.

If you could centrifuge beforehand, then the distillate would be pretty much pure.

A fancy schmancy jacket/coil condenser can be had for not much money if you plan on doing this often. I would suggest ordering a short column with support for packing while you're at it. Just don't look to aldrich or the like unless you are skilled in the art of ankle-grabbing.

Remember, the flow rate of your steam is only a fraction of the flow rate of your DCM, thus the need for extra cooling, and the controllable steam vent.

[Edited on 11-12-2006 by XxDaTxX]

Quince - 11-12-2006 at 11:09

Quote:
Originally posted by XxDaTxX
Just don't look to aldrich or the like unless you are skilled in the art of ankle-grabbing.

I'm not familiar with that euphemism.

unionised - 11-12-2006 at 11:33

You can probably consider yourself lucky. I understand that the idea is something like grab hold of your ankles and prepare to be "taken" :o from behind.
Aldrich are not cheap.- Don't get me wrong here, they are very good at their job, and we use there stuff a lot at work. It's just that I'm glad it's not my money we spend.

[Edited on 11-12-2006 by unionised]

Maya - 11-12-2006 at 11:35

Translation for those not familiar with this fancy chemical terminology:

"Aldrich charges you so much when ordering from them that it feels like you're getting it in the kiester"
:o



Q, sounds like you are overheating your distillation because your flask is hotter than the BP of DCM. Try a water bath at 45 deg or so and a rotovap or strong stirring with a slow distillation . I'll bet that will work

unionised - 11-12-2006 at 11:41

"Q, sounds like you are overheating your distillation because your flask is hotter than the BP of DCM. Try a water bath at 45 deg or so and a rotovap or strong stirring with a slow distillation . I'll bet that will work "
Good point Maya, I guess you will be right and if you are it saves me the bother of wondering what this low-boiling wax is and it may save endless trouble explaining how it might distill a couple of hundred degrees below its boiling point.

Quince - 11-12-2006 at 11:43

Well, they were the cheapest source of KCNS we found for our graphics project.

Maya - 11-12-2006 at 11:47

semimicro organic qualitative analysis of your wax , easy to do with standard chems, first year organic lab book will show you which tests to make to see what your wax is

unionised - 11-12-2006 at 11:53

Forgive me, it's a while since I did first year organic. My best guess is that the wax is a mixture containing celulose ethers, high molecular weight branched hydrocarbons, quite possibly a few polyalkyl benzene derivatives and some polyethyl/ propyl ene glycols. I could analyse it; but I'd rather not have to. (Actually, I'm not so sure about that because I'd get paid for doing it if I had to;).)

Quince - 11-12-2006 at 11:55

Hmm, I can only offer my body as payment at this time.

unionised - 11-12-2006 at 12:37

Looks like we will have to look at the datasheet.

Quince - 11-12-2006 at 12:54

Aww, you didn't accept my offer. Maya, you tell him dude, tell him how well I can pleasure

Maya - 11-12-2006 at 13:16

I wouldn't know, you guys just think evil thoughts all day


Now go do something productive like learning Org Chem ( as she cracks her whip again )

[Edited on 11-12-2006 by Maya]

unionised - 11-12-2006 at 13:23

( as she cracks her whip again )
Could you do that again please?:D