氨基磺酸修正碘量法测定亚硝酸盐存在情况下水中的溶解氧

为了测定较高浓度亚硝酸盐存在时水中的溶解氧 ,提出了氨基磺酸修正碘量法 ,实验结果表明 ,对于清洁水和废水 ,与标准碘量法相比 ,氨基碘酸修正碘量法在亚硝酸盐浓度约为 10mg L、4 0mg L、70mg L情况下测定结果的相对标准偏差均小于 1% ,相对误差均小于 2 % ,表明方法的准确度和精密度可以满足实验室测定DO的要求。本方法测定DO时对亚硝酸盐氮适用的上限为 70mg L。

DETERMINATION OF DO IN WATER CONTAINING NITRITE BY SULPHAMIC ACID MODIFIED IODOMETRY

To measure the dissolved oxygen (DO) in water containing high concentration nitrite,this artile presented sulphamic acid modified iodometry method.The results showed that the new method used to measure the DO concentration in clean water and wastewater respectively,whose results were compared with those of the iodometry method,the relative standard deviation and the relative error was below 1% and 2% respectively when the nitrite concentration was about 10 mg/L,40 mg/L and 70 mg/L in the water samples.The precision and accuracy of the modified iodometry method could fulfill the mensurement of DO in the Lab when the nitrite existed.The upper limit of nitrite for this method was 70 mg/L.