Appendix B: Measuring Special Samples
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Appendix B: Measuring Special Samples
B.1
Degassing Samples
There are different methods for the degassing of liquid samples. The preferable
method for your application depends on the kind of sample and the amount of gas
that is dissolved in the sample. Always take care that you treat all samples in the
same way in order to get reproducible measuring results.
Be aware of the fact that you may change the composition of many samples
slightly during the pretreatment due to evaporation of volatile components.
To boil the sample
1. Boil the liquid for several minutes to remove dissolved air.
2. Fill a clean glass flask full with the boiled liquid and cover it.
3. Wait until the liquid has cooled down to the approx. measuring temperature.
To stir the sample
•
Stir your sample vigorously for 2 to 15 minutes (depending on the stirring
equipment) until no bubbling occurs any more.
•
You can also pour the sample through a paper filter after stirring to get an
even more efficient degassing effect.
To use an ultrasonic bath
•
Put your sample for approximately 5 to 10 minutes into an ultrasonic bath
until the bubble formation stops.
WARNING
Boiling of liquids may induce a risk of fire and/or a health hazard.
•
Do not boil any flammable liquid because of a high risk of fire.
•
If your sample contains volatile compounds that are toxic, always handle it
in an appropriate environment like a fume hood, especially when you boil
your sample.
