Cleaning laboratory glassware may not be a simple affair like washing the utensils or dishes at home. It is generally, not so difficult to clean the laboratory glassware provided you know the rules of doing it right. Whenever detergent is used for cleaning the delicate glassware, you must invest in a detergent that has been specifically designed for the purpose like Alconox and Liquinox. Stay away from the temptation of using the usual dishwashing detergent.
More often than not, neither the water nor the detergent would be needed for cleaning laboratory glassware. You could simply rinse the glassware using an appropriate solvent and then complete the cleaning process by rinsing the glass container with distilled water and then with deionized water for the finishing touch.
Cleaning Glassware & Common Lab Chemicals
In case of water-soluble solutions such as sucrose solution or sodium chloride solution, you may consider rinsing thrice or four times with the help of deionized water. You may then put away the glassware safely until the next use.
In case of water-insoluble solutions like chloroform or hexane, you may consider rinsing twice or thrice with acetone or ethanol. Consider rinsing with deionized water three to four times. Then you could put away the glassware. In certain specific situations, some other solvents could be used while rinsing initially.
When you need to clean the lab glassware after handling strong acids such as H2S04 or HCL, rinse carefully with lots of tap water. Rinse thrice or four times using deionized water and then you may put the clean glassware away.
When the glassware needs to be cleaned scrupulously after handling strong bases such as concentrated NH4OH or 6M NaOH, under fume hood you must carefully rinse all the dirty glassware using huge volumes of running tap water. Then finally rinse with deionized water thrice or four times.
In case of weak acids like Acetic acid solutions you may simply rinse the glassware thrice or four times with deionized water while in case of weak bases such as NH4OH or 1M NaOH, you may rinse thoroughly with running tap water for removing all traces of the base. Then rinse the glassware three or four times with lots of water and finally with deionized water.
Washing Special Glassware
Burettes & Pipettes
You should wash using hot, soapy water and then rinse with tap water and deionized water a few times. In rare cases’ you might have to let your burettes, pipettes, and flasks soak in soapy water overnight or scrub hard with a brush or sponge. They need to be spotless to be used in quantitative lab work, or you might end up with wrong results or undesirable reactions.
Conclusion
It is recommended to avoid drying up glassware using forced air or paper towel as this could introduce impurities or fibers that could contaminate the solution. Glassware could be left to dry on their own. However, if you need to immediately use the glassware after cleaning them, you may consider rinsing the glassware in acetone twice or thrice. This would be effectively removing the water and will evaporate really fast.
Thank you,
Glenda, Charlie and David Cates
