Sciencemadness Discussion Board

Help identifying what seems to be an Extractor

Luigi.Dopobici - 2-10-2011 at 02:11

Hi,

I am new on this board. I am trying to determine what this thing is called. It looks like an advanced type of soxhlet extractor. any help appreciated. I found it at a flea market, new for 10 euros.

Thanks.


IMG_2189.jpg - 1.2MB

peach - 2-10-2011 at 04:00

I believe that's a piece of Kjeldahl equipment. As it has Buchi written on it, we can be safe in the knowledge that it did not originally cost 10 euros; Buchi light cigars with 10 euro notes, it will have been at least a few hundred.

I can't find the glass on the Buchi site (that piece you've got requires people to touch it and as we all know, humans are a.) lazy and b.) liars & cheats, so the newer stuff tends to be automatic).

The sample goes in that cup (internal flask) in the centre. Steam warms it to the boiling point of water, and then passes in through the tube in the side, blowing through the sample before going up to leave. There are two bump traps in the way to block any splattering from all the bubbling going on below.

Not a topic people tend to get into at home, but it's a very pretty bit of glass. I'd have bought it just to look at if nothing else.

You do now have a way to carry out steam distillations with very little messing around, as everything is in one piece and ready to go - no bits of tubing hanging off pressure cookers, et al.

There appear to be two minor problems with the way that piece of glass has been designed, in that doesn't look too easy to clean out the sample cup and the way the bump traps are laid out makes it possible for parts of the sample to get stuck; they're not self draining.

The cup with the tap on it is for introducing all your bits and pieces to the sample cup. The tubing connectors at the bottom and the other tap are from controlling your steam.

A diagram of something similar


Another variation


That's what it'd look like if it wasn't all assembled as one piece


A simplified version, put together as individual bits.


Buchi's super high tech, do it all for you, whizzy automatic Kjeldahl steam distillation unit
Quote:
The Kjeldahl method or Kjeldahl digestion (Norwegian pronunciation: [t͡ʃɛldɑːl]) in analytical chemistry is a method for the quantitative determination of nitrogen in chemical substances developed by Johan Kjeldahl in 1883.[1]

Method

The method consists of heating a substance with sulfuric acid, which decomposes the organic substance by oxidation to liberate the reduced nitrogen as ammonium sulfate. In this step potassium sulfate is added to increase the boiling point of the medium (from 337°F to 373°F / 169°C to 189°C). Chemical decomposition of the sample is complete when the medium has become clear and colorless (initially very dark).

The solution is then distilled with sodium hydroxide (added in small quantities) which converts the ammonium salt to ammonia. The amount of ammonia present (hence the amount of nitrogen present in the sample) is determined by back titration. The end of the condenser is dipped into a solution of boric acid. The ammonia reacts with the acid and the remainder of the acid is then titrated with a sodium carbonate solution with a methyl orange pH indicator.

Degradation: Sample + H2SO4 → (NH4)2SO4(aq) + CO2(g) + SO2(g) + H2O(g)

Liberation of ammonia: (NH4)2SO4(aq) + 2NaOH → Na2SO4(aq) + 2H2O(l) + 2NH3(g)

Capture of ammonia: B(OH)3 + H2O + NH3 → NH4+ + B(OH)4–

Back-titration: B(OH)3 + H2O + Na2CO3 → NaHCO3(aq) + NaB(OH)4(aq) + CO2(g) + H2O

Nowadays, the Kjeldahl method is largely automated and makes use of specific catalysts (mercury oxide or copper sulfate) to speed up the decomposition.

Applications

The Kjeldahl method's universality, precision and reproducibility have made it the internationally-recognized method for estimating the protein content in foods and it is the standard method against which all other methods are judged. It does not, however, give a measure of true protein content, as it measures nonprotein nitrogen in addition to the nitrogen in proteins. This is evidenced by the 2007 pet food incident and the 2008 Chinese milk powder scandal, when melamine, a nitrogen-rich chemical, was added to raw materials to fake high protein contents. Also, different correction factors are needed for different proteins to account for different amino acid sequences. Additional disadvantages, such as the need to use concentrated sulfuric acid at high temperature and the relatively long testing time (an hour or more), compare unfavorably with the Dumas method for measuring crude protein content.[2]




[Edited on 2-10-2011 by peach]

Luigi.Dopobici - 2-10-2011 at 04:53

THANXS!

Luigi.Dopobici - 2-10-2011 at 05:01

If I can´t figure out how to use it to extract lipids from solvents, then it will be the most unusual flower pot on the plant:-)

Any ideas? I am PhD biologist and it has been ,.....cough,....25 years since my last chemistry glass. I have some ideas from just staring at last night for about 2 hours, but maybe someone here has some REAL ideas:-)

Luigi.Dopobici - 2-10-2011 at 05:20

hey peach-your a peach! thank you!

I was about 75% correct in my thinking.


[Edited on 2-10-2011 by Luigi.Dopobici]

peach - 2-10-2011 at 05:32

If your lipids are present in water, you could add them as they are and run the steam through, as per a normal steam distillation.

If you're searching for fun things to try with it, you could have a go at making benzaldehyde (the compound in almond essence that makes it smell like cherries and marzipan).

Cinnamon oil contains a large amount of cinnamaldehyde (the thing that gives it it's spiciness);



When it's heated in a moderately high pH solution, it cleaves to benzaldehyde;



The process has been mentioned in at least two patents.

A guy called cycloknight in this thread has demonstrated it working.

All it really entails is adding some cinnamon oil to water with sodium bicarbonate in it, and then steam distilling. The benzaldehyde comes out with the steam, driving the process along.

The main drawback to doing it at home is having to set up the equipment. But you have it all in one there, like a mini reactor. You'd only need to copy the values he's using and divide them down to 100ml.

[Edited on 2-10-2011 by peach]

Luigi.Dopobici - 2-10-2011 at 05:49

I want to extract Cannabidiol from isopropanol and also from 80% ethanol.n

[Edited on 2-10-2011 by Luigi.Dopobici]

peach - 3-10-2011 at 07:59

Could you not remove the solvent?

Cannabidiol boils at 160 - 180°C, whereas iso-propyl is at 82.5°C and azeotropic ethanol, 78.1°C.

Assuming you have some kind of license, or permission, to deal with the quantity of cannabinoids involved, you could leave the lid off the bottle and put it on a radiator for a few days. The solvents will evaporate off into the atmosphere.

If the solutions are extractions of cannabis, there will undoubtedly be a mixture of other things in there. The only real way to separate those would be chromatography.

Luigi.Dopobici - 8-10-2011 at 12:27

thanks. I wash´t looking for that thing, i just found it at the flea market. I do NOT want to do anything big. Just to play around with. nothing illegal.

peach - 8-10-2011 at 15:15

Well, if you ever don't need it any more or find anything else interesting, I'll have it. ;)