Dissolved inorganic nutrients at station 17, Flügge (2020-04 - 2023-01)

In addition to data collection by the logger units, nutrients are measured at 23 locations. Sampling occurs every 14 days at each site. Samples are taken from a water depth of approximately 0.5 meters, filtered (filter size 40 µm), and cooled for further transport. Furthermore, on the sampling day, salinity and temperature are measured at the respective locations using the WTW Cond 3110. After each tour, the water samples are frozen at -20 °C at GEOMAR for later analysis. Since 2020/2021, the analyses have been conducted by Research Area 3: Marine Ecology, FE Experimental Ecology. GEOMAR, Kiel. The samples are analyzed for the concentration of dissolved inorganic nutrients (total oxidized nitrogen, nitrite, ammonium, phosphate and silicate) by UV/VIS spectroscopy using a continuous flow analyzer (type QuAAtro 30; comp. SEAL Analytical, Hamburg, Germany, equipped with a SEAL XY-2 autosampler). Quality control for nutrient measurements is ensured by certified reference material (CRM) by KANSO TECHNOS CO, LTD, Osaka, Japan. Standard analysis methods developed by SEAL Analytical were followed.

除通过数据记录仪单元采集数据外，本数据集在23个点位同步开展营养盐测定工作。各采样点每14天完成一次采样：从约0.5米水深采集水样，经孔径40 µm滤膜过滤后冷却，以待后续运输。采样当日，使用WTW Cond 3110型设备在对应点位测定盐度与水温。每次采样作业结束后，水样将被运送至德国基尔GEOMAR海洋研究中心，置于-20 ℃环境中冷冻保存，用于后续分析。自2020/2021年度起，相关分析工作由GEOMAR（基尔）第三研究领域——海洋生态学、FE实验生态学课题组负责开展。水样的溶解态无机营养盐（总氧化氮、亚硝酸盐、铵盐、磷酸盐与硅酸盐）浓度采用连续流动分析仪（型号QuAAtro 30，配套德国汉堡SEAL Analytical公司生产的SEAL XY-2型自动进样器）结合紫外-可见分光光度法完成检测。营养盐测定的质量控制通过采用日本大阪KANSO TECHNOS株式会社生产的有证标准物质（Certified Reference Material, CRM）实现。检测全程遵循SEAL Analytical公司制定的标准分析方法。