论文部分内容阅读
目前国内外测定自然硫的方法有氢氧化钠法,氰化钾法,二硫化碳或丙酮萃取紫外分光光度法,升华法,四氯化碳等有机溶剂浸取重量法,亚硫酸钠法等。亚硫酸钠容量法测定自然硫是国内使用较普遍的方法。此法快速、简便,但存在着终点不稳等问题。本文试就亚硫酸钠法的终点问题和空白值的问题提出一些看法。 一、终点不稳定的原因 目前国内各单位在用亚硫酸钠法测定自然硫时,亚硫酸钠的用量虽有不同(3～7克),但用碘标液滴定时,均以乙酸(1+1)调到
At present, the methods of determination of natural sulfur at home and abroad are sodium hydroxide method, potassium cyanide method, carbon disulfide or acetone extraction UV spectrophotometry, sublimation method, carbon tetrachloride and other organic solvent leaching gravimetric method, sodium sulfite method and the like. The determination of natural sulfur by the sodium sulfite volumetric method is a more common method used in China. This method is fast and easy, but there are problems such as unstable end point. This article tries to make some comments on the issue of the end point and the blank value of the sodium sulfite method. First, the reasons for the end of the instability At present, the domestic units in the determination of natural sulfur with sodium sulfite, although the amount of sodium sulfite (3 ~ 7 grams), but with iodine standard titration, acetic acid (1 +1) To