流动注射分光光度法测定亚硝酸盐仪器的研制

设计了亚硝酸盐流动注射自动在线监测仪，并研究了仪器的最佳测试条件．先将亚硝酸盐与对氨基苯磺酰胺重氮化，再与N-（1-萘基）乙二胺盐酸盐偶合，形成玫瑰红色的偶氮染料，在光程为60mm、光源为540nm的流通池内检测．实验发现最佳磺胺质量浓度为40g/L，N-（1-萘基）乙二胺盐酸盐质量浓度为0．6g／L，最佳采样量为300μL，反应管最佳长度为3m．亚硝酸盐的线性范围为10～1200μg／L，检出限为4．78μg／L，Rsd为1．02％（n=11），实际水样的加标回收率在96．5％～106．2％之内．本仪器消耗试剂量少、测定快速、灵敏、抗干扰能力强，适宜于现场即时监测．

Research of On-line Instrument to Determinate Nitrite by Flow Injection Spectrophotometric Analysis

A flow injection on-line analyzer for the determination of nitrite and researched the optimal condition were designed in this paper.Nitrite was determined directly using the Griess diazo-coupling reaction and the formed azo dye was measured at 540 nm in the 60 mm flow cell of the spectrophotometer.The optimal quality concentration of sulfanilamide is 40 g/L and N-(l-naphthyl)ethylenediamine dihydrochloride is 0.6 g/L,the optimal sample volume is 300 μL and the reaction coil length is 3 m.Nitrite can be determined within the range of 10～1200 μg/L with the detection limit of 4.78 μg/L and Rsd value(n=11) is 1.02%,the recovery value of environmental samples is in range of 96.5%～106.2%.The method consumes less reagent and is sensitive to determine instantly with rapid,simple,higher anti-interference ability.