All About Cleaning and Maintaining Laboratory Glassware
Even the most carefully executed experiment can give erroneous results if dirty glassware is bought to use. If the glassware that is used for measuring liquids is contaminated with grease and other materials, it prevents the glass from being uniformly wetted. This in turn will affect the volume of liquid delivered and the amount of residue adhering to the walls of the container. Likewise, presence of impurities in glass labware can distort the meniscus and can prevent one from getting the correct results out of the science lab experiment.
Keeping the laboratory glassware physically neat and clean, free of grease, and bacteria is therefore of the utmost importance.
To keep your glass labware neat and clean, you must wash it immediately after use. Put glassware in water if you can not clean it immediately otherwise the residue will stick to the labware and it would get difficult to remove it.
For washing the glass labware, make use of soap, detergent, or cleaning powder. Try to use soap and cleaning powder without any abrasives as it can scratch the glass. However, for glassware that is too dirty, you can make use of cleaning powder with mild abrasive action to get good cleaning results. Chromic acid solution is quite effective in cleaning unduly clouded or dirty glassware. For scrubbing the glassware thoroughly, you must use a brush.
After cleaning, rinse the glassware with tap water. Allow the water to run into and over the glassware and then fill each piece with water. Fill test tubes, flasks, and other glassware with water and shake and empty them. Do this for at least 5-6 times to clean the glassware properly. For cleaning contaminated glassware, you will have to sterilize them too.
Washed labware must either be placed in a basket with their mouth downwards for allowing them to dry completely or they should be made to dry in an oven. You can also hang test tubes, flasks, and other labware on wooden pegs for drying them out. Stand dry cylinders, burets, and pipets on a towel for drying them properly.
Place clean glassware in a cabinet to protect it from dust. You can also make use of cotton, or cork, or can tape a piece of paper on the mouth of the glassware to prevent dirt and dust from entering the glassware. Keep washed, cleaned, and sterilised glassware pieces in special racks and at a distance to avoid any breakage.
With proper care and maintenance you can not only increase the life of your labware, but can also enhance your lab safety.