当自己配制试剂进行总氮检测时，试剂的纯度是影响检测结果准确性的重要因素，需要注意的是过硫酸钾及氢氧化钠纯度。尤其是过硫酸钾溶液的配制对温度要求比较严格，需在低于60℃的水浴中加热。当过硫酸钾纯度达不到时该如何进行提纯操作呢？
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清洁干净的玻璃烧杯中加入约800mL去离子水，分批次逐渐加入过硫酸钾（0℃时过硫酸钾的溶解度为17.5mg/ L )，置于50℃水浴中加热完全溶解
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、将完全溶解的饱和溶液在室温下自然冷却，再放进4℃冰箱进行重结晶，重结晶过程为避免引入其他污染，可选用烧杯顶部盖上干净的表面皿或使用 PP 保鲜膜封口的方法密封，倒掉上清液，用4℃去离子水清洗3次重结鼎的晶体。
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、然后将重结晶晶体放入50℃烘箱烘干，重复以上步骤进行第2次重结晶，重结晶提纯后的固体过硫酸钾置于棕色玻璃试剂瓶中避光保存，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.
预制试剂的使用可以规避过硫酸钾纯度不够的问题，检测依据国标法，即开即用非常方便。
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.jnjhhg.cn
