dirtybastard (Hive Bee)
10-04-01 21:25
No 220524
      Purpose of washes/ wash suggestion  Bookmark   

Just wondering... what are the purposes of the washes (Sat. NaCl and sat. NaBicarb) in the benzoquinone wacker? Ol'Dirty know the NaOH removes the solvated quinone so it wont clog up the condensor, but why the others.

Also, In the past ODB has had difficulty seeing the different layers in the sep funnel during these washes. Often he uses a huge flashlight to look through the sep funnel. But what about this...
If you have say a >5L beaker, you could put your DCM/Ketone/wash mixture (~2L) in the beaker. You could then slowly run your water down the sides of the 5L beaker. As the water mixes with the "washed" part, the Ketone/ DCM (~500ml) would stay at the bottom of the flask. You'd be able to see the seperate layers much easier. Just a thought??

Man, I'm so high, I have no idea what's goin' on
(Distinctive Doe)
10-04-01 22:33
No 220548
      Re: Purpose of washes/ wash suggestion  Bookmark   

To wash out any residual NaOH and other garbage.  The salt will help keep the ketone in the DCM and keep water out of the DCM.

Do Your Part To Win The War
(Hive Bee)
10-05-01 13:20
No 220693
      Re: Purpose of washes/ wash suggestion  Bookmark   

Isn't the NaOH the last wash?
1st wash, NaCl
2nd wash, bicarb
3rd wash, 5% NaOH

Also, by what you are saying, the Ketone is soluble in water?

Man, I'm so high, I have no idea what's goin' on
(Hive Bee)
10-05-01 15:07
No 220725
      Re: Purpose of washes/ wash suggestion  Bookmark   

This was discussed ~ year ago. See Rhod's page for order of washes. If emulsion too thick, especially with salt wash, add more water and shake until emulsion is manageble. Otherwise bee afraid of losing product within emulsion. Let salt settle for long time.
(Hive Bee)
10-08-01 12:13
No 221758
      Re: Purpose of washes/ wash suggestion  Bookmark   

Jesus, Its like trying to read between you bees cryptic garble. UTFSE, blah, blah. Can't one of you answer the question with a real answer?

This bee has been sucessfull may times before, just wants to learn a little more.

Bright star says only wash with NaOH
MethylMan washes : Bicarb/ NaCl/ NaOH.

Now can anyone really answer my original questions?
1.What is the purpose of the Bicarb and NaCL washes.
2. Is it possible to keep adding water to the wash until the line of seperation is seen easliy?

If you can't answer then don't. Thanks

Man, I'm so high, I have no idea what's goin' on
(Junior Service Representative)
10-08-01 12:22
No 221762
      Re: Purpose of washes/ wash suggestion  Bookmark   

Is the sodium bicarbonate washes helpful in the post-animation process?  Dr.Gonzo suggested 2x NaCL, 2x NaCHO3, and 2xH2O, in that order. 

(Hive Bee)
10-08-01 21:38
No 222055
      Re: Purpose of washes/ wash suggestion  Bookmark   

Come on O'l Dirty, don't bust an arterywink Sorry, me english not so good. I'm a sayin if you have an emulsion, I wouldn't risk losing product by trying to find out where your water/DCM interface is by simply adding water down the side. I would add more water and gently shake. This will remove any possible product tied up in the emulsion. Use a bright light as you suggest. And let it settle a long time before draining dcm/product. This will give lots of time for product to work it's way down the emulsion. The salt washes can create quite an emulsion, so go easy on the salt during the first salt wash.