杜马斯燃烧法测定奶粉中蛋白质的方法研究

Determination of protein content in milk powder by dumas combustion method

以取样量、气体流量及通气时间为燃烧法测定样品蛋白质含量的关键影响点,采用单因素试验,建立起杜马斯燃烧法测定奶粉中蛋白质含量的优化条件:称样重量(200±20)mg,200 mL/min的氧气流量下,通氧100 s。通过精密度及加标回收验证实验,分析此优化测试条件的可行性,同时与国标仲裁法凯氏定氮法进行测试数据对比分析。结果显示:优化条件下的杜马斯燃烧法准确度高、重现性好、耗时少、安全环保,更加适用于大批量奶粉中蛋白质含量的快速分析。同时,对于测定过程中的注意事项进行了梳理,以更好的发挥检测服务效能。

Sample weight、gas flow and oxygen time are the key points for the determination of protein content in milk powder by combustion method.Dumas combustion method for determining the protein content of milk powder is established by single factor test:sample weight is(200±20)mg,oxygen flow is 200 mL/min,oxygen time is 100 s.Test the method’s feasibility by precision and recovery verification experiments,compare the test data with Kjeldahl method which is national standard arbitration method.The results show that the dumas combustion method under optimized conditions has the advantages of high accuracy,good reproducibility,less time consumption,safety and environmental protection and can meet the requirement of rapid analysis.It is more suitable for batch detection of milk powder.At the same time,comb the matters needing attention in the detection so as to better service the inspection.