Comparative Study on Pretreatment Methods for Determination of Total Nitrogen Content in Organic Fertilizers
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.
万方数据
维普
