National Oceanography Centre, Southampton, United Kingdom.
Environ Sci Technol. 2012 Sep 4;46(17):9548-56. doi: 10.1021/es300419u. Epub 2012 Aug 17.
Microfluidic technology permits the miniaturization of chemical analytical methods that are traditionally undertaken using benchtop equipment in the laboratory environment. When applied to environmental monitoring, these "lab-on-chip" systems could allow high-performance chemical analysis methods to be performed in situ over distributed sensor networks with large numbers of measurement nodes. Here we present the first of a new generation of microfluidic chemical analysis systems with sufficient analytical performance and robustness for deployment in natural waters. The system detects nitrate and nitrite (up to 350 μM, 21.7 mg/L as NO(3)(-)) with a limit of detection (LOD) of 0.025 μM for nitrate (0.0016 mg/L as NO(3)(-)) and 0.02 μM for nitrite (0.00092 mg/L as NO(2)(-)). This performance is suitable for almost all natural waters (apart from the oligotrophic open ocean), and the device was deployed in an estuarine environment (Southampton Water) to monitor nitrate+nitrite concentrations in waters of varying salinity. The system was able to track changes in the nitrate-salinity relationship of estuarine waters due to increased river flow after a period of high rainfall. Laboratory characterization and deployment data are presented, demonstrating the ability of the system to acquire data with high temporal resolution.
微流控技术使得传统上在实验室环境中使用台式设备进行的化学分析方法得以微型化。当应用于环境监测时，这些“芯片实验室”系统可以允许在具有大量测量节点的分布式传感器网络中就地执行高性能化学分析方法。在这里，我们展示了新一代微流控化学分析系统中的第一个，该系统具有足够的分析性能和稳健性，可用于天然水中。该系统可检测硝酸盐和亚硝酸盐（高达 350 μM，21.7 mg/L 为 NO3-），硝酸盐的检测限（LOD）为 0.025 μM（0.0016 mg/L 为 NO3-），亚硝酸盐的检测限为 0.02 μM（0.00092 mg/L 为 NO2-）。这种性能适用于几乎所有的天然水（除了贫营养的开阔海洋），并且该设备已部署在河口环境（南安普敦水）中，以监测不同盐度的水中硝酸盐+亚硝酸盐浓度。该系统能够跟踪由于高降雨量后河流水量增加而导致的河口水中硝酸盐-盐度关系的变化。本文介绍了实验室特性和部署数据，展示了系统以高时间分辨率获取数据的能力。
