Home method:
The most convenient way to wash glassware is to use soap, detergent, etc. to clean it with a brush, and then rinse it with tap water and distilled water in sequence. The surface of the cleaned glassware should be covered with a thin film of water when rinsed with distilled water; if there are small water droplets hanging on it, it means that it has not been cleaned.
Professional method:
For vessels that are difficult to clean with a brush and become unclean, the following cleaning solution can be prepared for chemical cleaning. For the utensils used for analyzing certain trace metals, they need to be soaked in a certain concentration of hydrochloric acid, nitric acid solution or a solution containing a complexing agent for a considerable time after washing to remove the metal ions adsorbed on the surface, and then rinsed with distilled water. Wash well.
Polyethylene, polyvinyl chloride, and polytetrafluoroethylene utensils can also be cleaned in the same way, but please note that plastic products are easily deformed when heated, easily scratched by hard objects, and are sensitive to many organic solvents.
1) Chromic acid wash solution: Weigh 92g of sodium dichromate dihydrate and dissolve it in 460mL of water, then inject 800mL of sulfuric acid. Another recipe is to inject 1L sulfuric acid into 35mL saturated sodium dichromate solution.
When the washing liquid turns green after use, it loses its washing ability. When using chromic acid washing liquid, the water content of the washed vessels should be small, and it is best to be dry to prevent the washing liquid from being diluted and reducing efficiency. Potassium dichromate can also be used instead of sodium dichromate, but the solubility of the former is lower. Containers washed with chromic acid cleaning solution should be fully rinsed with clean water to remove possible chromium ions.
2) Alkaline potassium permanganate washing solution. Weigh 4.0g of potassium permanganate and place it in a 250mL beaker. Then weigh 10.0g of sodium hydroxide and place it in the same beaker. Measure 100 mL of distilled water, add it in portions and stir continuously to fully dissolve potassium permanganate and sodium hydroxide. Carefully transfer the dissolved portion into a 200mL brown reagent bottle, and repeat this operation until all the potassium permanganate is dissolved. Rinse the beaker repeatedly with distilled water, and pour the rinse liquid into the brown reagent bottle until the inner wall of the beaker is no longer purple-red. Finally, dilute it to 100mL with the remaining distilled water, cap the bottle tightly, shake well, label it, and set aside. It is suitable for washing greasy glassware, but the remaining manganese dioxide needs to be washed away with hydrochloric acid or hydrochloric acid plus hydrogen peroxide.
3) Sodium hydroxide (potassium) ethanol solution: Add about 1L of 95% ethanol to 120mL of aqueous solution containing 120g of sodium hydroxide (potassium) to become a highly decontaminating solution Detergent, the glass grinding edge is easily damaged if it is exposed to this detergent for a long time.
4) Mixture of sulfuric acid and fuming nitric acid: suitable for particularly oily and dirty glassware.
5) Trisodium phosphate solution: Dissolve 57g trisodium phosphate and 28g sodium oleate in 470mL water. To remove carbonaceous residue from glassware, soak the vessel in this solution for a few minutes and then use a brush to remove the residue. 100~150g/L sodium hydroxide (potassium) solution also has the same effect.
6) 10g/L EDTA and 20g/L sodium hydroxide solution: Soaking washed glassware with this solution can remove some trace metal ions adsorbed on the surface of the container.
7) Hydrochloric acid ethanol solution: a mixture of one part hydrochloric acid and two parts ethanol, used to wash vessels stained by organic reagents.
8) Acidic oxalic acid lotion. Weigh 10g of oxalic acid or 1g of hydroxylamine hydrochloride and dissolve it in 20% 100mL hydrochloric acid solution. This cleaning solution can be used for utensils stained with oxides and water-soluble inorganic dirt (such as potassium permanganate, ferric iron).