Preparation method of alkaline potassium persulfate:
Weigh 40g of potassium persulfate and 15g of sodium hydroxide, dissolve them in ammonia free water, and dilute to 1000mL. In HJ636-2012, it is explicitly stated that the two solutions need to be prepared separately and must wait until the sodium hydroxide solution cools to room temperature before mixing the two solutions evenly.
This is because sodium hydroxide will generate heat when dissolved in water. If potassium persulfate and sodium hydroxide are dissolved in a beaker at the same time, some potassium persulfate will become ineffective due to excessive local temperature caused by the heat release of sodium hydroxide. Therefore, when preparing alkaline potassium persulfate solution, it is necessary to follow the regulations of HJ636-2012.
Potassium persulfate is not easily dissolved at room temperature and is often promoted by heating during preparation. However, potassium persulfate decomposes at 60 ℃ or even 50 ℃, so the heating temperature should be controlled below 50 ℃.
When preparing alkaline potassium persulfate solution, attention should be paid to:
① Dissolve potassium persulfate and sodium hydroxide separately, wait for the two reagents to cool to room temperature before mixing;
② The preparation of potassium persulfate solution requires heating for dissolution, but the temperature must be controlled below 60 ℃ to prevent the decomposition and failure of potassium persulfate;
③ The solution should be prepared immediately and stored for no more than 3 days. The amount of alkaline potassium persulfate added during digestion must be accurate.
Potassium persulfate, as an oxidant, should be stored in a dry place and should not be mixed with reducing substances, sulfur, phosphorus, etc. It should not be stored for too long.
Alkaline potassium persulfate solution cannot be stored for a long time. The standard stipulates that alkaline potassium persulfate solution cannot be stored in polyethylene bottles for more than 7 days. When alkaline potassium persulfate is stored in an environment of 27-30 ℃ for more than 3 days, the blank value will be greater than 0.030; It is recommended to prepare according to the demand for 3D as much as possible during the experiment, and store it as little as possible beyond 3D. If you have any doubts or needs, please feel free to come to our website at any time http://www.jinhao360.com consulting service