Bende-Michl Ulrike, Hairsine Peter B
CSIRO Land and Water, Black Mountain Laboratory, Clunies Ross Street, Black Mountain, Canberra, Australia.
J Environ Monit. 2010 Jan;12(1):127-34. doi: 10.1039/b910156j. Epub 2009 Nov 5.
Automated high frequency nutrient analysers have recently become available for in-stream monitoring of freshwater ecosystems. These instruments permit observation of nutrients at the same temporal frequency as discharge measurements. In principle this development will overcome some of the limitations of current water quality sampling and enable a better understanding of coupled terrestrial and aquatic environmental systems. This paper presents a systematic approach to choosing such instruments for research applications and informing the design of prescribed water quality monitoring. The instruments considered are ion-selective electrodes, wet chemistry analysers and ultraviolet/visible light spectrophotometers. Before committing to a new technology, investigators should evaluate instrument related considerations and complementary, often project-specific factors, in a structured way. The instrument related considerations are the ability of the instrument to measure the required nutrient parameters, the temporal resolution, the detection limits and range of individual measurements, required accuracy and operating temperatures as well as the overall cost. The complementary factors to consider are the maintenance effort, operating conditions, major service expenses and special consideration associated with individual instruments. This evaluation is presented for a range of available instruments across the three instrument types. As supplementary material a tabular approach that combines these factors is proposed and illustrated with a case study where instruments were selected for researching nutrient movement in a catchment in northern Tasmania, Australia. Few of the instruments can provide all the essential requirements of the case study and significant compromise of maintenance costs and functionality was necessary. The approach is readily adaptable to choices of instruments for a wide range of investigations concerning aquatic water quality. Clearly the outcome of the choice process is likely to be different for different applications, locations and environments.
自动化高频营养分析仪最近已可用于淡水生态系统的在线监测。这些仪器能够以与流量测量相同的时间频率观测营养物质。原则上，这一进展将克服当前水质采样的一些局限性，并有助于更好地理解陆地和水生环境系统的耦合关系。本文提出了一种系统方法，用于选择此类仪器用于研究应用，并为规定的水质监测设计提供参考。所考虑的仪器包括离子选择性电极、湿化学分析仪和紫外/可见光分光光度计。在采用新技术之前，研究人员应以结构化方式评估与仪器相关的因素以及通常因项目而异的补充因素。与仪器相关的因素包括仪器测量所需营养参数的能力、时间分辨率、单个测量的检测限和范围、所需的精度和工作温度以及总体成本。需要考虑的补充因素包括维护工作、操作条件、主要维修费用以及与单个仪器相关的特殊考虑因素。针对这三种仪器类型的一系列可用仪器进行了此项评估。作为补充材料，提出了一种结合这些因素的表格方法，并通过一个案例研究进行说明，该案例研究是为了研究澳大利亚塔斯马尼亚岛北部一个集水区的营养物质流动而选择仪器。很少有仪器能满足案例研究的所有基本要求，因此必须在维护成本和功能之间做出重大妥协。该方法很容易适用于各种有关水生水质调查的仪器选择。显然，对于不同的应用、地点和环境，选择过程的结果可能会有所不同。
