基于FIA的COD_(cr)在线测定研究

Study on On-line Determination of COD_(cr) Based on FIA

利用流动注射分析方法（FIA），建立了水样的化学耗氧量（COD）在线测定实验系统。采用K2C42O7和H2SO4溶液作为载流液，合适实验温度为170℃，压力为0．8MPa，吸收波长选择605nm。分别对低浓度、高浓度及高色度样品对应标准曲线进行了绘制。方法的相对误差为-2．7％～2．1％，相对标准偏差为1．02％～1．45％，回收率为98．5％～101．5％，分析结果具有较好的准确度与精密度。

A system for on -line determination of chemical oxygen demand （COD） in water sample was set up by flow injection analysis technique. K2Cr2O7 and H2SO4 solution is used as cartier solution. The optimal experiment temperature is 170℃ and the optimal experiment pressure is 0. 8 MPa, Absorption wavelength is selected at 605 nm. Standard curves are calculated for low concentration, high concentration and high chroma sample. The relative error of method is in the range of -2.7% -2. 1%. The relative standard deviation is in tile range of 1.02% ～1. 45%. The recoveries is in the range of 98. 5% ～ 101.5%. Analysis result shows that method has better accuracy and precision.