當自己配制試劑進行總氮檢測時，試劑的純度是影響檢測結果準確性的重要因素，需要注意的是過硫酸鉀及氫氧化鈉純度。尤其是過硫酸鉀溶液的配制對溫度要求比較嚴格，需在低于60℃的水浴中加熱。當過硫酸鉀純度達不到時該如何進行提純操作呢？
When the reagent is prepared for total nitrogen detection, the purity of the reagent is an important factor that affects the accuracy of the detection results. It is necessary to pay attention to the purity of potassium persulfate and sodium hydroxide. In particular, the preparation of potassium persulfate solution has strict temperature requirements, and it needs to be heated in a water bath below 60 ℃. When the purity of potassium persulfate is not up to the standard, how to carry out the purification operation?
1、在1000mL清潔干凈的玻璃燒杯中加入約800mL去離子水，分批次逐漸加入過硫酸鉀（0℃時過硫酸鉀的溶解度為17.5mg/ L )，置于50℃水浴中加熱完全溶解
1. Add about 800ml deionized water into a 1000ml clean glass beaker, gradually add potassium persulfate in batches (the solubility of potassium persulfate is 17.5mg/l at 0 ℃), and heat it in a water bath at 50 ℃ until it is completely dissolved
2、將完全溶解的飽和溶液在室溫下自然冷卻，再放進4℃冰箱進行重結晶，重結晶過程為避免引入其他污染，可選用燒杯頂部蓋上干凈的表面皿或使用 PP 保鮮膜封口的方法密封，倒掉上清液，用4℃去離子水清洗3次重結鼎的晶體。
2. The completely dissolved saturated solution is naturally cooled at room temperature, and then put into a 4 ℃ refrigerator for recrystallization. In order to avoid introducing other pollution during the recrystallization process, the top of the beaker can be covered with a clean surface dish or sealed with PP fresh-keeping film, the supernatant is poured out, and the crystals of the reconstituted tripod are washed with 4 ℃ deionized water for three times.
3、然后將重結晶晶體放入50℃烘箱烘干，重復以上步驟進行第2次重結晶，重結晶提純后的固體過硫酸鉀置于棕色玻璃試劑瓶中避光保存，有效期1周。
3. Then put the recrystallized crystal into a 50 ℃ oven for drying, repeat the above steps for the second recrystallization, and place the solid potassium persulfate after recrystallization and purification in a brown glass reagent bottle to keep away from light. The validity period is 1 week.
預制試劑的使用可以規避過硫酸鉀純度不夠的問題，檢測依據國標法，即開即用非常方便。
The use of prefabricated reagents can avoid the problem of insufficient purity of potassium persulfate. The detection is based on the national standard method, which is very convenient and efficient.
The above is the detailed introduction of potassium persulfate for you. I hope it will help you. If you have any questions, please contact us. We will provide you with services in a professional manner http://www.gddxcpa.com
