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prepare external standard solutions in organic solvents

Discussions about sample preparation: extraction, cleanup, derivatization, etc.

11 posts Page 1 of 1
Do you guys use class A glass pipettor or some sort of automatic dilutor? Sometimes, it is just difficult to work with volatile organic solvents. such as ethyl acetate, DCM?
I've always use either Class A pipettes or Hamilton syringes, but I'm a bit "old school". I have never had trouble working with organic solvents.
Don Shelly
Don Shelly Consulting, LLC
don.shelly@donshellyconsulting.com
Use syringes made by Hamilton. They are very accurate and will last a very long time if you rinse them with solvent when you are finished working.
We use either class A volumetric pipets and volumetric flasks, or a Hamilton MicroLab dispenser/diluter and volumetric flasks.
Glass pipettes, autodispensers, syringes, micropipettes - I use any and all of them and check my actual additions by weighing before and after addition, and I calculate actual final concentrations on the basis of the weights.

Peter
Peter Apps
We use Electronic Hamilton diluter. It works really fine
Hamilton syringes into volumetric flasks most of the time. For small volumes I use just the syringes.

Had a difficult one a while back, trying to make a stock standard of Vinyl Bromide in Methanol. Finally figured out I needed to place the 10ml volumetric on the balance, then place the Vinyl Bromide ampule and the syringe in the freezer, then use the cold syringe to dispense the VB into the Methanol filled volumetric until I got the correct weight.

Tried it warm and the VB just shot out of the syringe all over the place :( live and learn.
The past is there to guide us into the future, not to dwell in.
Hamilton syringes into volumetric flasks most of the time. For small volumes I use just the syringes.

Had a difficult one a while back, trying to make a stock standard of Vinyl Bromide in Methanol. Finally figured out I needed to place the 10ml volumetric on the balance, then place the Vinyl Bromide ampule and the syringe in the freezer, then use the cold syringe to dispense the VB into the Methanol filled volumetric until I got the correct weight.

Tried it warm and the VB just shot out of the syringe all over the place :( live and learn.

I always bubbled the gas directly into the volumetric while on the balance until the desired mass was achieved.
Don Shelly
Don Shelly Consulting, LLC
don.shelly@donshellyconsulting.com
Hamilton syringes into volumetric flasks most of the time. For small volumes I use just the syringes.

Had a difficult one a while back, trying to make a stock standard of Vinyl Bromide in Methanol. Finally figured out I needed to place the 10ml volumetric on the balance, then place the Vinyl Bromide ampule and the syringe in the freezer, then use the cold syringe to dispense the VB into the Methanol filled volumetric until I got the correct weight.

Tried it warm and the VB just shot out of the syringe all over the place :( live and learn.

I always bubbled the gas directly into the volumetric while on the balance until the desired mass was achieved.
I used that technique when I had a gas cylinder standard, but this time I could only get the standard in liquid form.

Funny thing was the first time I tried it I didn't think about the boiling point of the VB, since the storage instructions on the ampule was room temperature. I broke open the ampule, and began to use a disposable pipette and all of a sudden all of my standard was gone lol. That's when I looked up the boiling point and found it to be sub ambient. Felt really bone headed not realizing the analyte was normally a gas at ambient temperature.
The past is there to guide us into the future, not to dwell in.
Can halmiton microlab 600 work with organic solvents, such as ethyl acetate?

Glass pipettes, autodispensers, syringes, micropipettes - I use any and all of them and check my actual additions by weighing before and after addition, and I calculate actual final concentrations on the basis of the weights.

Peter
Can halmiton microlab 600 work with organic solvents, such as ethyl acetate?

Glass pipettes, autodispensers, syringes, micropipettes - I use any and all of them and check my actual additions by weighing before and after addition, and I calculate actual final concentrations on the basis of the weights.

Peter
I'm not sure why you are asking me ? What do Hamilton say about it ?

Peter
Peter Apps
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