What level of contamination could be present in an evaporation/condensation glass tube?

Question

Given a used condensation and evaporation system, thoroghly cleaned several times, and used several times for the purpose of ethanol condensation, what levels of contamination from prior use could conceivably exist?

Answer 1

If it's ONLY been used for ethanol condensation, then there's the possibility of residual fusels...a good washing with a bottle brush and some detergent...alconox or PBW should do the trick. If you want to be really sure, completely fill the water jacket with water, and put it in an ultrasonic cleaner that's large enough to hold its entire length...that'll get everything that the brush won't reach. If the the brush or the ultrasonic doesn't get it, you could soak it in denatured alcohol for a few hours/days and then give it a thorough soap and water scrubbing...should be as good as new. All of the by-products in ethanol condensation are soluble in a soap/detergent solution.