When it comes to cleaning laboratory glassware like flasks or a beaker, it’s not like doing the dishes: you can just do them in the sink with a cloth. Nor can you throw them in the dishwasher with a tablet of Finish and expect them to be ready for work. The beaker needs to be clean, obviously, but they also need to be clear of any contaminants that could ruin the next laboratory experiment or chemical solution. Here are some tips on how to clean a beaker <https://au.rs-online.com/web/c/test-measurement/lab-equipment/jugs-beakers/ >
Don’t wait. It’s generally easier to clean a beaker if you do it right away and make sure you use laboratory-grade detergents designed for lab glassware. Where possible, avoid domestic detergents which may have trace chemicals that can compromise future work.
That said, most of the time you’ll want to avoid detergents altogether. It’s best to use an appropriate solvent and rinse with either distilled then deionised water. Which solvent you need depends on what you’re cleaning out of the beaker.
Water Soluble Solutions like salt or sugar compounds are easily cleaned. Simply rinse the beaker 3-4 times with deionised water then put it away.
For Water Insoluble Solutions such as hexane or chloroform, use ethanol or acetone for the first rinse, then rinse again in deionised water.
A beaker that has contained a Strong Acid should be cleaned thoroughly with tap water under a fume hood. Then rinse out with deionized water.
Strong Bases should also be cleaned under a fume hood with the same method as for strong acids (with care, using tap then deionised water).
The same applies to both Weak Acids and Weak Bases; rinse thoroughly with tap water then deionised water. You may not need the fume hood, depending on just how weak the acid or base is.
To Dry or Not To Dry
That is a good question. Typically you’re best to simply put a beaker on the shelf after washing and let it air-dry. This all but eliminates the possibility of introducing fibres or impurities that can arise when using a cloth, paper towels or even forced air. Just wash, stack and you’re done.
However, sometimes you’ll want to use a beaker immediately after washing. It may be ok to introduce water into the experiment, and sometimes it won’t be. If a beaker must be dry, rinse it in acetone 2-3 times – this will remove the water, and acetone evaporates quickly leaving the beaker dry and ready to go.
- When a beaker has stubborn contaminants and needs a thorough cleaning, use a laboratory-grade brush to scrub all parts of the glassware.
- If basic cleaning or scrubbing hasn’t removed all the chemicals or compounds, leave it to soak in a gentle solvent.
- Remember to turn your beaker upside down when leaving it to air dry. This reduces the possibility of airborne contaminants getting inside clean glassware.
- Always follow safety guidelines when using acid solutions and other potentially harmful substances.