Views:9 Author:Site Editor Publish Time: 2019-06-03 Origin:Site
The instruments often used in experiments should be washed and dried after each experiment. Instruments used in different experiments have different requirements for drying, and should be dried according to different requirements. What are the requirements for drying and storage of glass instruments?
I. drying of glass instruments
The instruments often used in experiments should be washed and dried after each experiment. Instruments used in different experiments have different requirements for drying. In general quantitative analysis, beaker, conical flask and other instruments can be used after washing, while many instruments used in organic chemistry experiments or organic analysis require drying, some require no water trace, some require no water. The instrument should be dried according to different requirements.
If it is not urgent to dry, it should be generally dry. After rinsing with pure water, remove the water in a dust-free place and then dry naturally. You can install the shelves with inclined wooden nails and glass cabinets with air holes to place the instruments.
2.The instrument is washed, dried and placed in an oven in an electric oven, and the temperature is controlled to be baked at 105-120 ° C for 1 h, and can also be dried in an infrared drying oven.
3. Hot (cold) air blown, for eager drying equipment or larger instruments that are not suitable for use in the oven, you can use a small amount of ethanol, acetone (or finally ether) to pour moisture In the instrument, the solvent is controlled by washing (solvent is recovered), then blown with a hair dryer, and then blown with cold air for 1-2 minutes. When most of the solvent is volatilized, the hot air is blown to completely dry, and then the residual steam is blown by cold air to make it No longer condensed in the container.This method requires good ventilation, prevents poisoning, and is not exposed to open flames to prevent organic solvents from exploding.
II. Keeping of glass instruments
The glassware in the storage room should be stored in separate categories for easy access. The glassware that is often used is placed in the test cabinet. It should be placed in a safe, high, and large place. Here are some ways to keep the instrument.
1.After cleaning, place the straw in the dust box.
2.After the burette is used, wash the solution inside and fill it with pure water. Cover the glass short tube or plastic sleeve, or put it upside down on the burette rack.
3. After washing the cup plate, place the filter paper under the porcelain plate or plastic plate, and then dry it up and put it into a cup box or a clean container.
4. In the cleaning instrument with an abrasive volume bottle stopper or the tube color than before, preferably with a rubber band or a small rope tied spout and the plug, to avoid breaking the plug or mixed together. To keep the grinding instrument for a long time, pad a piece of paper between the plugs to avoid sticking. Long-term use of buburet to remove Vaseline liner paper, use a rubber band to plug the piston to save.
5. The whole set of instruments, such as soxhlet extractor and gas analyzer, shall be cleaned immediately after use and stored in a special carton.
In short, we should be responsible for the spirit of the work, all the glass instruments used to clean up, according to the requirements of storage, to develop good working habits, not in the instrument left behind oil, acid, corrosive substances (including concentrated lye) or toxic drugs, so as to avoid future trouble.