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Topic: mixing water and non polar analytes  (Read 1989 times)

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Offline strokebow

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mixing water and non polar analytes
« on: February 22, 2013, 06:36:57 PM »
Hi

I have to mix a concentration of toluene in water. Please what is the best way for me to achieve a good mixture so I can have a consistent concentration in equilibrium throughout the mixture.
 Thanks

Offline strokebow

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Re: mixing water and non polar analytes
« Reply #1 on: February 23, 2013, 07:44:02 AM »
How about mixing in flask using magnetic stirrer??
If its fast enough, it should mix, right? But will it be a proper mixture or not? because the spinning motion will make a vortex so will oil just concentrate at the middle?

Also, I have seen an example where people have made a homogeneous mixture of oil and water but it is on industrial scale:
http://www.eesiflo.co.uk/static-mixer-motionless.html
How can i do this in the lab?

Any ideas or suggestions would be very much appreciated?
NB I would like to avoid the use of an emulsifying agent.
« Last Edit: February 23, 2013, 08:20:35 AM by strokebow »

Offline Arkcon

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Re: mixing water and non polar analytes
« Reply #2 on: February 23, 2013, 08:29:10 AM »
Then you will want some sort of emulsifying device.  These things use rotors with very little space between them, to sort of shear the oil droplets into small sizes that will disperse throughout the water.  Likewise, a through run with ultrasound emulsifier may work.  But with no emulsifying agent at all, I can't guarantee the emulsion will be stable -- for minutes, or even seconds.  Maybe some ionic solid, like NaCl, may provide some charged separation, adding a tiny amount of time to the stability.  But you may simply have to work quickly.
Hey, I'm not judging.  I just like to shoot straight.  I'm a man of science.

Offline strokebow

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Re: mixing water and non polar analytes
« Reply #3 on: February 23, 2013, 09:49:03 AM »
Thanks for your reply. Its tough one.

So you think using the stirrer wont really work? Or atleast not for long.
How about use of an emulsifying agent? That would do the job... however, it will introduce an 'impurity' in to my mixture which I don't really want.

I'll have a look in to the ultrasonic emulsifier.

Anyone else have any ideas/suggestions? thanks





Offline strokebow

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Re: mixing water and non polar analytes
« Reply #4 on: February 24, 2013, 01:09:46 PM »
I was thinking if I add some methanol. So for my solution if I hsve say, 90:10 (or some other ratio) ratio of water to methanol?? And then dissolve the toluene in it.

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