Bio:
Email: 1552794965@qq.com
商姗姗(1990—),女,大学本科,工程师,主要从事肥料、土壤及化工产品的检测工作;1552794965@qq.com
行业标准《有机肥料》(NY/T 525—2021)中测定有机肥料的总氮含量采用浓硫酸-过氧化氢消煮法处理样品,不仅耗时长,而且操作复杂。参考国家标准《复混肥料中总氮含量的测定蒸馏后滴定法》(GB/T 8572—2010)中的硫酸-混合催化剂消化法,采用上述2种方法分别消解有机肥样品,用凯氏定氮法测定有机肥中总氮的含量。结果表明:2种方法平行测定结果的绝对差值均符合标准要求,且准确度较好;硫酸-混合催化剂消化法操作简单,消解时间短,检测效率高,可用于大批量有机肥样品总氮含量的测定;浓硫酸-过氧化氢消煮法得到的消解液不仅可用于总氮含量的测定,还可用于总磷和总钾含量的测定,而硫酸-混合催化剂消化法得到的消解液只能用于测定总氮含量。
In the industry standard Organic Fertilizer (NY/T 525—2021), the total nitrogen content in organic fertilizers is determined by using the concentrated sulfuric acid-hydrogen peroxide digestion method to process samples, which is not only time-consuming but also complex to operate. Referring to the sulfuric acid-mixed catalyst digestion method in the national standard Determination of Total Nitrogen Content for Compound Fertilizers: Titrimetic Method After Distillation(GB/T 8572—2010), the organic fertilizer samples are digested using the above two methods, and the total nitrogen content in the organic fertilizers is determined using the Kjeldahl nitrogen determination method. The results show that the absolute differences between the parallel measurement results of both methods meet the standard requirements and have good accuracy; the sulfuric acid-mixed catalyst digestion method has simple operation, short digestion time and high detection efficiency, and can be used for the determination of total nitrogen content in large-scale organic fertilizer samples. The digestion solution obtained by the concentrated sulfuric acid-hydrogen peroxide digestion method can not only be used for the determination of total nitrogen content, but also for the determination of total phosphorus and total potassium content, while the digestion solution obtained by the sulfuric acid-mixed catalyst digestion method can only be used for the determination of total nitrogen content.