Liquid nitrogen needs to be used frequently in laboratory research, such as high pressure freezing, cryosection, and cryo-electron microscopy, but the temperature of liquid nitrogen is extremely low, so the safe use of liquid nitrogen is also very important.
One: application of liquid nitrogen
1: frozen sample
2: as a second refrigerant when it is put into freezing
3: Freezing instrument
4: Store samples
2. Physical properties of liquid nitrogen
Melting point 63K/-210°C
Boiling point 77K/-196"C
Face-to-face: 1: Frostbite (in the laboratory, the boiling temperature is generally used, and the liquid hydrogen has a Leidenfrost Effect effect. Temporary protection by the insulating gas layer)
How to prevent: Do not directly control with liquid nitrogen. Do not take a long time to contact the body of the nitrogen body, do not touch the liquid oxygen for a long time, which phase is wet clothes.
2: Insufficient oxygen (1L of liquid nitrogen can be vaporized into 700L of nitrogen to reduce the oxygen content in the air. Oxygen in the atmosphere
The most 21%, less than 18% will damage the health of the body and mind, less than 11% will have great risks, such as injury or even death. example
For example, a closed 3*3*2.5 space, 10L of liquid nitrogen can reduce the oxygen content to 16%)
How to prevent: Do not use a lot of liquid hydrogen in a small space, work in a well ventilated environment, use an oxygen monitor and calibrate frequently, do not work alone.
3: Explosion (in a confined space, vaporized liquid nitrogen will quickly increase the pressure of the container. For example: filled in a sealed container
50% of the liquid nitrogen pressure can reach 350bar, if the container can not withstand such a large pressure, it will explode quickly. )
How to prevent: Just cover the liquid nitrogen with a less sealed lid and use a professional liquid nitrogen tank.
4: Condensation of liquid oxygen (oxygen in the air will condense in liquid hydrogen, and liquid oxygen will ignite or react with organic materials.)
How to prevent: Do not store liquid nitrogen in the container for too long.
Understand the risks of liquid nitrogen, understand the regulations of the laboratory and comply with them.
Sales Manager: Amanda Hou