Glassware
Proper use of all kinds of glassware is very important to reduce personal injury. Damaged glassware is not allowed in the laboratory. For glassware that cannot be repaired, it should be disposed of in accordance with waste. The chemicals remaining in the glassware should be removed before repairing the glassware.
Laboratory personnel should pay attention to the following when using various 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 splashing of the glass. 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 should be placed in a special trash can. The broken glass is rinsed with water before it is placed in the 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, it is prohibited to 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.
 
2. Rotary evaporator
The rotary evaporator is a commonly used instrument in the laboratory. Pay attention to the following items when using it:
(1) The pressure applied to the rotary evaporator is generally 10 to 30 mmHg.
(2) Each connecting part of the rotary evaporator is fixed with a special clip.
(3) The solvent capacity in the rotary evaporator flask should not exceed half.
(4) The rotary evaporator must be rotated at an appropriate speed.
 
3. Vacuum pump
Vacuum pumps are equipment for filtration, distillation and vacuum drying. There are three types of commonly used vacuum pumps: 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. Pay attention to the following when using:
(1) A 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) Before using it, first cool the distillate, then slowly deflate, then close the balance after reaching equilibrium.
(4) The oil pump must be changed frequently.
(5) The rubber hose on the exhaust port of the oil pump should be connected to the fume hood.
 
4. Fume hood
The role of the fume hood is to protect laboratory personnel from toxic and harmful gases, but not all toxic gases. Pay attention to the following when using:
(1) Chemicals and laboratory equipment cannot be placed at the exit.
(2) Ventilation cannot be turned off during the experiment.
 
5. Thermometer
Thermometers generally include 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. Laboratory personnel should use a suitable thermometer. 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 out by a pipette, placed in a specific closed container and marked, and disposed of by the chemical reagent company, and then the remaining mercury is covered with sulfur and cleaned after several days.
 
6. Gas cylinder
The contents of the cylinder are often under high pressure. When the cylinder is dumped, exposed to heat, or subjected to irregular operation, it may cause an explosion. In addition to explosive and easy to spray, cylinder gas is flammable, toxic and corrosive. Therefore, the use of cylinders should pay attention to:
(1) Characteristics of normal safety gas cylinders:
1 The surface of the cylinder should have a clear label indicating the gas name.
2 cylinders are color-coded.
3 All gas cylinders must be equipped with a pressure relief valve.


(2) Storage of gas cylinders:
1 Compressed gas is a first-class dangerous goods, the number of cylinders stored in the laboratory is minimized, and hydrogen is strictly prohibited in the laboratory.
2 gas cylinders should be placed upright against the wall and prevent dumping measures; exposure to sunlight, away from heat, corrosive materials and potential impact should be avoided; cylinders should not be placed in corridors and foy to prevent obstruction and other accidents during emergency evacuation. occur.
3 flammable gas cylinders and combustion-supporting gas cylinders shall not be mixed; flammable and flammable pressure cylinders shall not be less than 10 meters away from open flame; flammable gas and toxic gas cylinders shall be placed outdoors and placed in a standardized and safe manner. In the iron cabinet.


(3) Use of gas cylinders:
1 Clean the water and dust at the outlet of the cylinder valve before opening the pressure reducing valve. After the cylinder is used, the cylinder main valve is closed and the excess pressure in the pressure reducing valve is released. The helmet must be put on (except for the helmet in the original design) to prevent the valve from being damaged. Care must be taken when removing the helmet to avoid inadvertent opening of the cylinder main valve.
2 Do not use the cylinder completely (especially acetylene, hydrogen, oxygen cylinders), and must maintain a certain positive pressure.
3 Gas cylinders must be used in well ventilated areas where the pressure reducing valve and outlet valve are intact, and local ventilation should be added when toxic gases are involved.
4 Wear protective goggles, face shields, gloves, and work aprons when using cylinders containing toxic or corrosive gases. It is strictly forbidden to strike and collide with the pressure cylinder.
5 Oxygen cylinder pressure reducing valves, valves and pipelines are prohibited from oiling or grease.
6 cylinder transfer should use the cylinder trolley and keep it upright, while closing the pressure relief valve.
 
7. Centrifuge
Centrifugation is a very effective route for solid-liquid separation, especially when separating small solid particle suspensions. Pay attention to the following points when using:
(1) When using a centrifuge, the centrifuge tube must be symmetrically balanced, otherwise water should be used as a balance to keep the centrifuge balanced.
(2) Cover the centrifuge before starting the centrifuge, start at a lower speed, and then adjust to the desired centrifugal speed.
(3) When the centrifugation operation is finished, 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 the plastic centrifuge tubes to avoid deformation of the tubes during centrifugation.
(5) The centrifuged solution is generally controlled to about half of the volume of the centrifuge tube, and it is not possible to put too much liquid in order to avoid the liquid from escaping during centrifugation.
 
Syringe
When using the syringe, it is necessary to prevent the needle from being stabbed and the syringe broken and hurting 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 in case they are misused.
 
9. Refrigerator and freezer
The refrigerator in the laboratory has no explosion-proof device and is not suitable for storing flammable, explosive and volatile solvents.
(1) It is strictly forbidden to store personal food in the refrigerator and freezer.
(2) All low boiling point reagents stored in refrigerators and freezers should have a standardized label.
(3) All containers placed in the refrigerator and freezer shall be sealed, the refrigerator cleaned regularly and unnecessary samples and reagents removed.