Do you know the precautions for using a laboratory rotary evaporator?

1. When using a rotary evaporator, first draw a small vacuum (about 0.03MPa), then start rotating to prevent the distillation flask from slipping; when stopping, first stop rotating, hold the distillation flask with your hand to let air in, and wait until the vacuum drops to about 0.04MPa, then stop the vacuum pump to prevent the distillation flask from falling off and sucking back.

2. When using a rotary evaporator, a layer of vacuum grease must be applied to each interface, sealing surface, sealing ring, and connection before installation.

3. Water must be added before heating and powering on, and dry burning without water is not allowed.

4. If the vacuum degree of the rotary evaporator is found to be too low during use, pay attention to check the air tightness of each joint, vacuum tube, and glass bottle.

5. When distilling gas-sensitive substances, connect a nitrogen balloon to the exhaust port, first exhaust the air in the rotary evaporator through a stream of ammonia, and then connect the sample bottle for rotary evaporation. After evaporation, release the ammonia gas to pressurize, then turn off the vacuum pump and take out the sealed sample bottle.

6. If the sample has a significant effect on viscosity, the rotation speed should be slowed down and the sample should be rotated slowly manually to form a new liquid surface to facilitate solvent evaporation.