Proper use of glassware is very important to reduce personal injury. Damaged glassware is not allowed in the laboratory. If it cannot be repaired, it should be disposed of in accordance with the waste. Residual chemicals should be removed before repairing glassware.
1. Wear protective gloves when installing the glass tube on the rubber stopper or rubber hose. First, smooth the ends of the glass tube with fire and apply water or grease to the joint as a lubricant. Do not attempt to pull on the glassware that is bonded together to avoid hurting your hands.
2. The outer layer of the dewar should be covered with a layer of tape or other protective layer to prevent the glass from splashing when broken. The glass distillation column should also have a similar protective layer. When using glassware for extreme pressure (above atmospheric or subatmospheric) operation, it should be done after the protective baffle.
3. The broken glass is rinsed with water and placed in a special trash can.
4. When performing vacuum distillation, appropriate protective measures (such as plexiglass baffles) should be used to prevent the glassware from exploding or rupturing and causing personal injury.
5. Ordinary glassware is not suitable for pressure reaction, even at lower pressures, so do not use ordinary glassware for pressure reaction.
6. Do not place heated glassware on a cold surface to prevent the glass from breaking due to sudden changes in temperature.
1. The applicable pressure is generally 10 ~ 30mmHg.
2. Each connecting part is fixed with a special clip.
3. The solvent capacity in the flask should not exceed half.
4. Must be rotated at an appropriate speed.
Vacuum pumps are equipment for filtration, distillation and vacuum drying. There are three types of vacuum pumps commonly used: air pumps, oil pumps, and circulating water pumps. The pump and oil pump can be vacuumed to 20 ~ 100mmHg, and the high vacuum oil pump can be vacuumed to 0.001 ~ 5mmHg.
1. The cold trap must be connected before the oil pump.
2. The water in the circulating water pump must be replaced frequently to prevent the residual solvent from being detonated by the motor spark.
3. After the end of use, first cool the distillate, then slowly deflate, then reach the balance and then close.
4. The oil pump must change oil frequently.
5. The rubber pump exhaust port should be connected to the rubber tube and connected to the fume hood.
The fume hood protects the laboratory personnel from toxic and harmful gases, but it does not discharge all toxic gases.
1. Do not place chemicals and laboratory equipment at the exit.
2. Never turn off ventilation during the experiment.
There are alcohol thermometers, mercury thermometers, quartz thermometers and thermocouples. Low temperature alcohol thermometer measuring range -80 °C ~ +50 °C; alcohol thermometer measuring range 0 °C ~ +80 °C; mercury thermometer measuring range 0 °C ~ +360 °C; high temperature quartz thermometer measuring range 0 °C ~ +500 °C, thermocouple Not commonly used in the laboratory. The thermometer should not be used as a stir bar to avoid breakage or breakage, resulting in other hazards. After the mercury thermometer is broken, most of the mercury should be sucked up with a straw, placed in a specific closed container and marked, and the remaining mercury is covered with sulfur, and cleaned up after several days.
The contents of the cylinder are often under high pressure. When the cylinder is dumped, exposed to heat, or irregular operation, it may cause an explosion. In addition to explosive and easy to spray, cylinder gas is flammable, toxic and corrosive.
1. The surface of the cylinder should have a clear label indicating the gas name and a color code.
2. All gas cylinders must be equipped with a pressure relief valve.
3. Compressed gas is a Class 1 dangerous product. The number of cylinders stored in the laboratory should be reduced as much as possible. It is strictly forbidden to store hydrogen in the laboratory.
4. Gas cylinders should be placed upright against the wall and prevent dumping measures. Avoid exposure to heat, away from heat, corrosive materials and potential impact. Cylinders should not be stored in corridors and halls to prevent obstruction and other accidents during emergency evacuation. occur.
5. The flammable gas cylinder and the combustion-supporting gas cylinder shall not be mixed. The flammable and flammable pressure cylinder shall not be less than 10 meters away from the open flame. The flammable gas and toxic gas cylinders shall be placed in an outdoor standard and safe iron cabinet. in.
Centrifugation is a very effective route for solid-liquid separation, especially when separating small solid particle suspensions.
1. The centrifuge tube must be symmetrically balanced.
2. Cover the lid before starting, start at a lower speed, and then adjust to the desired centrifugal speed.
3. At the end of the operation, the lid must be opened after the centrifuge has stopped running. Never open the lid or touch the rotating part of the centrifuge before the centrifuge is completely stopped.
4. Glass centrifuge tubes require higher quality. Hot or organic solvents should not be placed in plastic centrifuge tubes.
5. Centrifugal solution is generally controlled at about half of the volume of the centrifuge tube. Do not put too much liquid.
When using the syringe, prevent the needle from stabbing and the syringe from damaging the hand. The needle and the syringe should be tightened to prevent leakage. Used syringes must be washed in time. Useless syringes should be destroyed and disposed of again to prevent misuse by others.
Refrigerator And Freezer
The laboratory refrigerators are free of explosion-proof devices and are not suitable for storing flammable, explosive, and volatile solvents.
1. It is strictly forbidden to store personal food.
2. All low boiling point reagents stored in refrigerators and freezers should be labeled as standard.
3. All containers stored in the refrigerator and freezer must be sealed, the refrigerator should be cleaned regularly and unnecessary samples and reagents removed.