Chromatography Forum

Hello everybody.

I was wonderig how you would clean your small volumentric flasks after preparation of Standardsolutions for GC/MS if you do not have a labdishwasher.

I was thinkig about rinsing it several times with some solvents (Acetone, etc.)

Thanks vor your help.

Rinsing with solvent may even be better than the dish washer. Using the dish washer you add detergent and then remove it with water. And that water has things in it that have made their way from the watersupply to the dishwasher...

And the way the dishwasher removes the detergent: multiple rinses with a solvent (water).

Check blanks made in you clean glassware. (you should check blanks as you work anyhow.)

Personally i wash 5 mL and 10 mL volumetric flasks used for GC/MS analysis this way:

- First rinse with acetone to get anything i can out of the flask
- Second rinse with acetone in an ultrasonic bath for 5 minutes
- 1 night (at least) in a 2L Becher in a bath of hot water, soap and acetone
- Multiple rinses with distilled water (this part is important to get all the soap away)
- Final rinse with acetone
- Room temperature dry

I know it's damn long and boring, but it works for me and i can do this by having a good number of flasks, so i can cycle cleaning them to have always some flasks ready.

If you have any suggestion i would be pleased to hear it.

Thanks for the imput

I will Test some blanks and your sugestions
And if i come up with something New i will share IT with you

Since the neck diameters of those are too small to drain properly with our dishwasher, I rinse them with solvents several times, similar to that described above.

Great practical question, though.

A soak overnight (or 10mins sonicating) in good lab detergent like Decon will shift anything. After that, rinse well with tap water then finish with 2-3 times RO water, dry in an oven. If they don't dry well then a rinse with acetone before the oven does the trick. As said above, dishwashers struggle with small things like this.

If the flasks are used only to make standards in clean solvents then the less they see of detergents and dishwashers the better - they can only add contaminants. Repeated rinses with small quantities of clean solvent is the way to go.

Peter