碱性过硫酸钾氧化法测定海水总氮方法的改进

对<我国近海海洋综合调查与评价专项-海洋化学调查技术规程>的海水总氮测定方法碱性过硫酸钾氧化法进行了改进,减少水样转移次数与定量移取步骤,对改进方法的精密度、准确度、回收率和空白值等指标与<规程>法进行了比较,并验证了改进方法的有机氮氧化率、加标氧化率和海水加标回收率.结果表明,改进方法的精密度、准确度、回收率和空白值均符合总氮测定要求,有机氮加标氧化率和加标回收率符合<规程>的要求,说明了改进方法可靠,简化了步骤、缩短了时间,节省了试剂用量和器皿,更适于船上现场测定.

Improvement on determination method of total nitrogen in seawater by alkaline potassium persulfate

The improvement of determination method of total nitrogen in seawater by the alkaline potassium persulfate was done, optimizing the Technique Regulations in the marine chemical investigation and assessment on the marine environment in offshore. The accuracy, precision, rate of recovery and blank value of this improved method are compared with that of the method of the Technical Regulation. And the rate of organic nitrogen oxidation,rate of addition recovery and recovery of standard addition of this optimized method were verified in this paper. The results showed that the accuracy, rate of recovery and organic nitrogen oxidation of this improved method could be accorded with the requirement of the Technique Regulations,and the accuracy , rate of recovery and blank value were better than the method of Technical Regulation. It showed that this improved method was reliable. The processing steps, analytical time and amount of samples are reduced. So this optimized method is better than that in Technique Regulations for the determination on ship.