Chromatography Forum

( 5 : 5 :2 v/v)

i think it 5ml from the first solvent , and 5 ml from another solvent , and 2 ml

but what if i have to make up to 100 ml with these three solvent using the same percent ( 5 : 5 :2 v/v)



thanks

If it were me, I would do the following:

Fill one 50 mL volumetric with solvent A

Fill one 50 mL volumetric with solvent B

Fill one 20 mL volumetric with solvent C

Combine all in a beaker, allow to equilibrate (in case of any exothermic/endothermic mixing reactions), then fill a 100 mL volumetric with the mixture. That way, you keep your 5:5:2 ratio without having to make any complicated measurements of volume.

If you need to make more, or will need more in the future, you could go 250:250:100 and combine to give 600 mL of a 5:5:2 mixture.

Thank u very much bisnettrj2 for your way of prepare it but the combine mixture will be ( 120 ml ) how can i put it in 100 ml flask ?

any way i like your method

Ronaldo,

If you absolutely insist on preparing 100 mL of the mixture, then you’ll need to use the following volumes:

41.67 mL : 41.67 mL : 16.67 mL

Does it help?

Best Regards

bisnettrj2 suggested making up a slight excess because if you mix solvents whose volumes add up to exactly 100mL, you may not end up with 100mL. For example, 50mL water + 50mL methanol makes 50%MeOH, but not 100mL! There is a volume change.

Bisnettrj2's method makes exactly the solvent you describe, and relies on you to measure the correct volume.

lmh, danko, thanks for helping me out here...

speacial thanks to you all