论文部分内容阅读
我局内燃机车每年需要12000吨左右的3号配方冷却液。冷却液中的主要成分之一是亚销酸钠,无论是新配制还是在机车运用过程中都必须经常检测其浓度以保证冷却液符合部颁标准。这项工作对于机务段化验室来说工作量是相当大的。而目前对于冷却液中高含量的亚硝酸钠(1800～2200mg/L)的测定大都采用高锰酸钾容量滴定法。用该方法滴定时,重现性差,误差也较大,并相当费时。如果采用高锰酸钾间接滴定虽可提高准确度、精密度,但操作较麻烦,效率不高。作者在稀乙酸溶液中利用NO_2~-被硫脲还原为SCN~-与Fe~(3+)显色,在波长γ=453nm下
I Bureau diesel locomotive each year requires 12,000 tons of No. 3 formula coolant. One of the main components in the coolant is sodium suberate, either freshly prepared or in the process of locomotive operation must always be tested to ensure that the coolant meets Buban standards. The workload for the depot laboratory is considerable. At present, most of the determination of high content of sodium nitrite (1800 ~ 2200mg / L) in the coolant using potassium permanganate volumetric titration. Titration with this method, the poor reproducibility, the error is larger, and quite time-consuming. If the use of potassium permanganate indirect titration can improve the accuracy and precision, but the operation is more cumbersome, inefficient. In the dilute acetic acid solution, the use of NO2 ~ - was reduced to thiourea SCN ~ - with Fe ~ (3 +) color, at a wavelength of γ = 453nm