Use of liquid nitrogen
Liquid nitrogen is often used as a refrigerant. Refrigerant can cause frostbite, a small amount of refrigerant can cause blindness if it contacts the eyes, and the rapid evaporation of the gas produced by liquid nitrogen may cause oxygen deficiency in the on-site air. When using and handling liquid nitrogen, pay attention to:
1. Wear insulating protective gloves.
2. Wear a long-sleeved lab coat that is knee-length.
3. Wear shoes that do not expose the ankle, wear protective glasses, and wear a protective mask if necessary.
4. Keep the ambient air flowing.
Use of lotion
The lotion is divided into acidic lotion (sulfuric acid solution of sodium dichromate or potassium dichromate), alkaline lotion (sodium hydroxide-ethanol solution) and neutral lotion (commonly used detergent).
Put the acidic lotion in a glass tank, and the alkaline lotion in a plastic bucket.
When using alkaline washing liquid, the grinding parts of the glass instrument should be disassembled and then put into the washing liquid tank, so as to prevent the grinding port from being corroded by alkaline liquid and bonding. Glassware should be pre-washed with acetone and water before placing in lye.
