How to clean the lab equipment?Date: 2022-11-22Number: 604
Common laboratory glassware such as measuring cups, test tubes, titrators, pipettes, measuring bottles and so on. Equipment in the use of the process will be stained with oil, scale, rust stains, and so on, after the use of not complete cleaning in a timely manner, will lead to the result of deviation, even on the use of equipment life, performance will also have a very bad impact. Therefore, chemical experiments using glassware must be clean and tidy.
Washing methods for some glassware:
(1) wash with water
According to the shape of the glassware to be cleaned to choose suitable for their own brush, such as test-tube brush, cup brush, flat brush, brush, such as titration tube. With a brush dipped in water to wash, soluble substances can be dissolved, but also stick to the glass of dust and insoluble matter off, but many times can not wash out the grease and organic matter.
(2) Wash with detergent
You can use a brush dip cleaning, carefully brush the inside and outside walls of glassware. In order to ensure the efficiency of cleaning, detergent can be mixed into 1% -5% of the water solution, heating invasion bubble to wash glassware. After a few minutes, continue to brush repeatedly.
(3) cleaning with ultrasonic cleaning machine specially used for laboratory instruments. The special ultrasonic cleaning machine in the laboratory is based on the principle of efficient ultrasonic cavitation effect, in which water molecules vibrate in glassware and shake off pollutants on the surface of equipment, under the influence of ultrasonic cleaning machine with rapid cleaning dead angle, GAP, replace the traditional manual cleaning can not place. Eventually, you just need to dry the equipment and it's ready to be used again.
Second, choose detergent
Under normal circumstances, you can use the synthetic detergent on the market to clean glassware. When the insoluble substance is attached to the inner wall of the equipment, it can not be cleaned with synthetic detergent. The proper detergent should be selected according to the nature of the adhesive. If the adhesive is alkaline, dilute hydrochloric acid or sulfuric acid can be used to react and melt the adhesive, and if the adhesive is alkaline, sodium hydroxide solution can be used to react and melt the adhesive If the adhesive is a substance which is difficult to dissolve in acid or alkali, but soluble in some organic solvents, this kind of organic solvent is selected as detergent to dissolve the adhesive.
In the laboratory, as well as specially formulated cleaning fluid, can be reused several times.
In view of many inconvenient to clean with a brush into cleaning dirty utensils, can be configured with the following cleaning liquid for chemical cleaning. For containers used for the analysis of certain trace metals, the surface adsorbed heavy metal ions have to be removed by soaking in a specific concentration of hydrochloric acid, nitric acid or a solution containing a complexing agent for a considerable period of time after cleaning, then rinse clean with distilled water.
3. Master the operation steps of cleaning glass instruments
For simple instruments, such as test tubes, with easily removable substances. Beakers, etc, to be cleaned with a tube brush dipped in a synthetic detergent. Turning or. When moving the brush up and down, apply proper force to avoid damaging the equipment and scratching the skin.
Some glass instruments with fine and complicated structure can not be cleaned by brush, such as measuring bottle, pipette, etc. .
The cleaning operation is as follows: at the beginning of cleaning, check whether the rubber disc on the piston is fastened to avoid sliding and damage during cleaning, pay special attention to whether there is leakage into clogging phenomenon, if there is an adjustment. Close the piston and pour 2-3 ml cleaning solution into the burette. Slowly tilt the burette to the level and turn the burette slowly so that the inside wall is soaked by the cleaning solution. Raise the burette, then unscrew the piston and release the cleaning fluid so that the piston's human segment can also be washed. Then Wash with daily tap water, the same from the lower tip of the piston out, can not save time and labor for the liquid from the upper end of the mouth of the pipe.
Clean the glassware immediately
Cleaning the glassware immediately is helpful in choosing the right detergent for you, since it is easier to determine the nature of the residue at that time. In some chemical experiments, the residue after the reaction is immediately poured out, and there are no hard-to-remove appendages on the inner walls of the equipment, but after a period of time, the volatile solvent escapes, the residue will stick to the inside of the equipment, making cleaning difficult. There are many substances, and the instrument itself part of the reaction, if not timely cleaning will lead to equipment damage, and even damage.
Other common points for attention
Do not use all kinds of laboratory reagents as detergent, and do not use all kinds of laboratory reagents to clean glassware. Not only is it a waste of medicine, it's also dangerous.