实验用水对总氮检测结果的影响

用RO纯水与超纯水分别作为实验用水,通过标准曲线及空白、标准样品、水样等总氮测定对比实验,发现两种实验用水的标准曲线及空白值、标准样品的检测均受控,但两种纯水对比实验显示相对于超纯水而言,RO纯水中有一定浓度的总氮,同时在水样检测中用RO纯水作实验用水测定值明显低于用超纯水作实验用水的测定值,其差值与RO纯水中总氮值相符。实验结果表明总氮检测中不能只以标准曲线、空白值和标准样品测定值作为受控标准,要考虑实验用水中硝酸根离子的影响。

Influence of Experimental Water on the Determination Results of Total Nitrogen

The RO pure water and ultrapure water were used as experimental water to determine total nitrogen through the comparison experiment of standard curve, blank concentration, standard sample and water sample. However, it was found that the detection of standard curve, blank concentration and standard sample of both water were controlled. But the comparison experiment showed that compared to ultrapure water, there was certain quantity of ＂IN in RO pure water. Moreover, the determination result of TN using RO pure water as experimental water was much lower than that of ultrapure water, and the difference of TN equals to the TN value in RO pure water. Therefore, it is not enough to use only standard curve, blank value and standard sample as control criterion for the determination of TN, but also need to consider the influencing of nitrate ion in experimental water.