海水硝酸盐／亚硝酸盐原位快速测量仪

In-Situ Instrument for Rapid Detection of Nitrates and Nitrites in Water

基于SIA顺序注射法以及分光光度原理研制了海水硝酸盐/亚硝酸盐原位快速测量仪。对最佳不完全显色反应时间以及硝酸盐镉铜柱还原速度进行了实验优化筛选,采用液芯波导替代比色皿作为样品池,在实现原位快速测量(测量时间可短至4min)的同时也大大减少了样品量,缩小了仪器体积、重量,降低了仪器功耗,提高其灵敏度(nmol·L-1),使其更适于原位测量。仪器具有良好的通用性和可扩展性,稍作调整,即可用于不同海域各种营养要素的剖面及定点测量。

A new in-situ instrument to simultaneously and rapidly detect the nitrates and nitrites of water is presented based on the sequential injection analysis （SIA） and spectrophotometer. The optimal time and injection speed for incomplete chemical color reaction of nitrite with reagent and deoxidization efficiency of cadmium column on changing nitrate to nitrite were studied and selected to obtain the rapid detection speed （the detection time for a sample can be as short as 5 mins for nitrates and 4 min for nitrites） of nitrates and nitrites in situ. In this instrument, the liquid-core waveguide （LCW） was adopted to replace the quartz cuvette as the colorimetric cell to obtain a relatively low detection limit（nmol· L^-1 ） and very small sample consumption, and all water sample was filtered before sample injection and measurement. These measures make this in-situ detection instrument have the advantages of complete automation, very quick detection speed, low weight and power consumption, and good versatility and extensibility. Only by replacing the reagent or LCW, it also can be used to measure the trace element of water or other nutrition elements such as phosphate, silicate etc, in different sea areas in profile or fixed-point.