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Newbee P-Benzo wacker ?

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SPISSHAK:
When you wash do you go staight to NaOH? or do you wash first with saline or bicarbonate?
The reason behind this is that the first wash has a nasty tendancy towards emulsions, you can also overcome this by gently swirling the two layers of the first wash in the sep funnel, as opposed to shaking which may result in an emulsion, also if your washing with base it's helpful to use dcm or another appropriate non-polar to seperate the phases and keep the organic layer a little dilute since it's in contact with a strong base which can do nasty things to it.
And my ass is as smooth as silk.

BlingBling:
I see! Good thing I asked.

I didn't think that the NaOH washes were that effective. I suppose after 3, it would be a waste.

How is it that plain old h2o gets discolored when added? What about excessively washing with saline and bicarbonate? Another waste of time??

>>When you wash do you go staight to NaOH? or do you wash first with saline or bicarbonate?

Sometimes, depends on what's closest. Lately the DCM collections haven't been pooled in with the organic collection, but set aside to be distilled at a later date. I notice alot less emulsion, but have thought about what you said when doing this. I can see how the addition of DCM could be of use when determining which layer is which, and making the consitancy of the organic matter a little more manageable.

Upon distillation of the DCM collections that were gathered over 3 wackers, I expected about 100-125 ml's at most. I was impressed when 250ml's came over. It proved that DCM is similiar to a car pool that transports kids from point A-Z. A valuable chemical that I love to smell on occasion.

I suppose either way you look at it, you will have that emulsion to deal with. The DCM collections got a NaOH wash regardless, how the two are mixed, appears to determine how much emulsion you will have to play with.

I found that a beaker and a stir bar is a great way to minimize emulsion, gently stirring, but enough to mix both layers nicely. Not as nice as your smooth ass, but nice.

Thanx for the help, saved me a pointless time consuming experiment. (and alot of NaOH)

Rhodium:
I didn't think that the NaOH washes were that effective. I suppose after 3, it would be a waste.

How is it that plain old h2o gets discolored when added? What about excessively washing with saline and bicarbonate? Another waste of time??

Don't quote me on "80%" being the exact figure, but it is at least somewhere between 50-90% (that doesn't matter really, with 50% extraction efficiency the numbers would be 100% -> 50% -> 25% -> 12.5% -> 6.25% -> 3.1%, that is five washes to remove over 95% of what can be removed. With the extraction efficiency being 90%, only two washes would be needed for 99% removal (100% -> 10% -> 1%).

The purpose of the sodium hydroxide washes is to remove the bulk of the hydroquinone and other acidic contaminants, while the purpose of the carbonate is to "pre-wash" the solution with a weakly basic solution so that certain surfactants like alkyl carboxylates are removed prior to the NaOH washes as to lower the risk of creating intractable emulsions. Brine washes of the non-polar layer dries it crudely by osmotic suction.

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