水质总氮测定中无氨水的替代用水研究

国标《GB/T11894-89》规定,测定总氮时需要使用无氨水,而制备无氨水费时费力,成本高,因此很不适合大批量样品的分析。该研究使用氨氮快速测定仪分别对一次蒸馏水、新制双蒸水、无氨水等多种不同的实验用水内的氨氮含量进行了实测,结果表明：二次重蒸馏水（新制）的氨氮含量（0.80mg/L）低,接近无氨水（0.70～0.90mg/L）中实测的氨氮含量。研究使用该替代用水进行了国标总氮测定试验,经总氮空白实验验证,结果满足国标总氮测定中对空白值的要求,即A≤0.030,同时,标准曲线线性相关性系数R2=0.9987。运用该试验用水进行实测标样和水样中氨氮的含量,结果准确、精密度良好,完全能满足实际测定的要求,因此具有实际应用的价值。

Research on the Alternatives of Non-ammonia Water in Determination of Total Nitrogen in Water Quality Analysis

According to the regulation GB/T 11894-89,non-ammonia water must be used throughout the determination of total nitrogen in water qauality analysis.The preparation of non-ammonia water,however,needs a lot of time,labor and money,so the non-ammonia water is not suitable for the determination of lots of samples.Ammonia ISM is used to measure the concentration of ammonia in distilled water,newly prepared double distilled water and non-ammonia water;the result shows that the ammonia concentration in newly prepared double distilled water is relatively low（0.80mg/L）,and it is close to that of non-ammonia water（0.70～0.90mg/L）.They find that the blank experiment （A ≤0.030）,standard curve（R2=0.9987）,accuracy and preciseness all meet the needs in standard and sample determination while following the GB standard.The results indicate that this method has its value in application.