Development & Application of Proposal of Shipboard and In-Situ Chemical Sensors for Oceanographic Research

9521618绿色一种由渗透泵驱动的连续流动分析仪已被开发出来，用于监测浸入淡水或海水中的硝酸盐浓度。由氯化钠梯度驱动的渗透泵推动样品和试剂通过微型连续流动歧管。该分析仪的样品和试剂流速分别为每月约8.0毫升和0.7毫升，在0-20微摩尔硝酸盐范围内呈线性响应，检测下限为0.1微摩尔，90%响应时间约为30分钟。该分析仪通过定期进样和分析已知标准溶液来校正基线和灵敏度漂移，从而自动对自身进行标准化。该系统已在淡水和海水中连续运行长达一个月之久，可适用于各种比色分析。这里支持的研究将采用这项示范技术，并开发化学分析各种痕量金属(即铁、锌、镉、铜和锰)以及其他宏观营养物质(即二氧化硅和磷酸盐)。这类分析仪的潜在应用包括海洋学研究以及环境监测和工业过程控制。

9521618 GREEN A continuous flow analyzer powered by osmotic pumps has been developed to monitor nitrate concentrations while submerged in freshwater or seawater. Osmotic pumps driven by a NaCl gradient propel both sample and reagents through a miniature continuous flow manifold. The analyzer operates with sample and reagent flow rates of about 8.0 and 0.7 ml per month, respectively, shows a linear response from 0 to 20 micromolar nitrate with a detection limit of 0.1 micromoles, and has a 90% response time of approximately 30 minutes. The analyzer automatically standardizes itself by correcting for baseline and sensitivity drift by periodically injecting and analyzing known standard solutions. The system has operated continuously for month-long periods in freshwater and seawater, and can be adapted to a variety of colorimetric analyses. The research supported here will take this demonstrated technology and develop the chemistries to analyze for a variety of trace metals (i.e., iron, zinc, cadmium, copper and manganese), as well as other macro-nutrients (i.e., silica and phosphate). Potential applications for such analyzers include oceanographic studies as well as environmental monitoring and industrial process control.