【摘要】 探索了海水中COD测定的分光光度法研究,以海洋监测规范为基础,前处理(消解)部分与海洋监测规范COD分析方法相同,用比色法代替硫代硫酸钠滴定法,经过扫描波长选择524nm,比色介质高锰酸钾碱性条件稳定性较差,酸性条件下稳定性较好,消解后颜色的稳定时间10min左右,浓度越高颜色越不稳定,该方法标准曲线的相关系数比规范法高,主要是消除了人为误差。更多还原

【Abstract】 This text investigated a new analytical method of measuring the COD in seawater by spectrometry. This analytical method is based on "the marine monitoring norm". The sample pretreatment (digestion) is the same as the method described in "the marine monitoring norm", but the spectrometry is used to replace titration with sodium thiosulphate. By the experiment, 524nm is chosen as the measuring wavelength. It has been observed that the colorimetric stability of potassium permanganate is better in acid condition than in alkaline condition. After digestion, the color of digest solution can be stable about 10 minutes. Higher the COD concentration is, more unsteady the solution color is. The related coefficient of the standard curve is higher than norm method, and primarily reason is that the artificial errors are eliminated. 更多还原