顺序注射亚硝酸盐检测仪的研制及应用

Development of a sequential injection analyzer and its application in the determination of nitrite in environmental water samples

基于顺序注射分析技术与格里斯试剂比色法的原理,研制了一台全自动检测环境水样中亚硝酸盐的仪器,并成功应用于实际水样的检测.该仪器经优化调试后的物理条件为管内径0.8 mm、定量环长度90 cm、反应时间3.5 min;格里斯化学试剂的改进结果为磷酸体积分数为11%,磺胺(SA)浓度为45 g·L-1,N-(1-萘基)-乙二胺盐酸盐(NED 2HCl)浓度为50 mg·L-1.在最优化条件下,亚硝酸盐的线性检测范围是10—1000μg·L-1,检出限为4.14μg·L-1,相对标准偏差1.2%,实际水样的加标回收率在105.4%—122.1%之间.由于本仪器操作便捷,灵敏度高,抗干扰能力强,因此适用于全自动在线实时检测.

An automatic instrument based on sequential injection analysis technique and Griess reagent colorimetric method was developed and applied to the determination of nitrite in environmental water samples. The instrument＇s physical parameters were optimized as follow： the tuner diameter of pipe, 0. 8 mm; length of sample loop, 90 cm; reaction time, 3.5 min. The optimized composition of the colorimetric neagents were that the volume fraction of phosphoric acid was 11%, and concentrations of sulfonamides （SA） and N-（1-naphthyl）-ethylenediamine hydrochloride salt （NED 2HC1） were 45 g· L-1 and 50 mg · L-1, respectively. Under the optimized conditions, a linear rang of 10-1000 μg·L-1 , detection limit of 4.14 μg·L-1 , relative standard deviation of 1.2% and recovery rate of 105.4%-122. 1% were achieved. The instrument is simple, automatic, reliable and therefore applicable for on-line and real-time determination of nitrite in complex water samples. Keywords： sequential injection analysis, nitrite, spectrophotometry, online monitoring, water quality analysis.