空气整段间隔连续流动分析法快速测定环境水样中的COD

The Rapid Determination of Chemical Oxygen Demand in Aqueous Environmental Samples by Monosegmented Continuous Flow Analysis

本文应用空气整段间隔的连续流动分析技术,对环境水样中的COD进行了测定。采用KMnO_4作氧化剂和光度分析指示剂,葡萄糖作COD的基准物质,在反应温度为95℃,反应时间为8min时,采样频率可达90样/时,检出限2mg/L,相对标准偏差0.7%,回收率85～95%。Cl^-<1500mg/L时不干扰测定。

A new method is described for the rapid determination of chemical oxygen demand (COD) in aqueous environmental samples by monosegmented continuous flow analysis. The method uses acidic potassium permanganate solution as both an oxidant and a spectrophotometric reagent, and glucose as a standard. When the reaction temperature is 95 C,reaction time is about 8 minutes,the sampling frequency is 90/h. The detection limit and relative standard deviation are 2 mg/L and 0.7%, respectively. The recovery of COD is 85—95%. Choride ion up to 1500 mg/L level does not interfere.