Phosphorus is a key indicator for water quality management due to its role in eutrophication. The variety of phosphorus-containing substances necessitates highly sensitive detection of total phosphorus, particularly through automated methods, to ensure water safety. This study involved the independent development of a sensor featuring an automated in situ detection technique. Utilizing potassium persulfate high-temperature oxidation and phosphorus molybdenum blue spectrophotometry, total phosphorus was monitored in situ via sequential injection technology. Additionally, the detection process and reaction conditions of the sensor were optimized, and a temperature compensation algorithm and turbidity correction were applied to mitigate environmental factors. Under optimal conditions, the sensor demonstrated a detection limit of 1.9 µg/L with a range of 6.5–1000 µg/L in seawater, and 1.2 µg/L with a range of 4.1–2000 µg/L in freshwater. The digestion efficiency for five representative phosphorus-containing substances was found to range from 87.3% ± 1.7% to 103.1% ± 0.6%. Notably, the sensor was deployed for in situ operation at a marine experimental station and online at a river monitoring station. With its integration, low power consumption, and high precision, the sensor enabled long-term unattended monitoring, delivering accurate, stable, and reliable results.

中文翻译：

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基于 K2S2O8 氧化法的自动原位传感器，用于海水中总磷的检测


由于磷在富营养化中的作用，因此它是水质管理的关键指标。含磷物质的多样性需要对总磷进行高度灵敏的检测，特别是通过自动化方法，以确保水安全。本研究涉及独立开发具有自动原位检测技术的传感器。利用过硫酸钾高温氧化和磷钼蓝分光光度法，通过顺序进样技术原位监测总磷。此外，优化了传感器的检测过程和反应条件，并应用温度补偿算法和浊度校正来缓解环境因素。在最佳条件下，传感器在海水中的检测限为 1.9 μg/L，检测范围为 6.5–1000 μg/L，在淡水中的检测限为 1.2 μg/L，检测范围为 4.1–2000 μg/L。5 种代表性含磷物质的消化效率在 87.3% ± 1.7% 到 103.1% ± 0.6% 之间。值得注意的是，该传感器被部署在海洋实验站进行原位操作，并在河流监测站进行在线操作。凭借其集成度、低功耗和高精度，该传感器可实现长期无人值守监测，提供准确、稳定和可靠的结果。