Le Goff Thierry, Braven Jim, Ebdon Les, Chilcottt Neil P, Scholefield David, Wood John W
Department of Environmental Sciences, University of Plymouth, Drake Circus, UK.
Analyst. 2002 Apr;127(4):507-11. doi: 10.1039/b201899n.
A field evaluation of a novel nitrate-ion selective electrode (ISE) was undertaken by continuous immersion over a period of 5 months in agricultural drainage weirs. The nitrate sensor N,N,N-triallyl leucine betaine was covalently attached to polystyrene-block-polybutadiene-block-polystyrene (SBS) using a free radical initiated co-polymerisation, to produce a rubbery membrane which was incorporated into a commercially available electrode body. A measurement unit was constructed comprising the nitrate-ISEs, a reference electrode and a temperature probe connected through a pre-amplifier to a data-logger and battery supply. A temperature correction algorithm was developed to accomodate the temperature changes encountered in the drainage weirs. The nitrate results obtained with the ISEs at hourly intervals compared very favourably (R2 = 0.99) with those obtained with laboratory automated chemical determinations made on contemporaneous samples of drainage in a concentration range 0.47-16 ppm nitrate-N. The ISEs did not require re-calibration and no deterioration in performance or fouling of the membrane surface was observed over four months of deployment.
通过在农业排水堰中连续浸泡5个月，对一种新型硝酸根离子选择性电极（ISE）进行了现场评估。使用自由基引发的共聚反应将硝酸根传感器N，N，N-三烯丙基亮氨酸甜菜碱共价连接到聚苯乙烯-嵌段-聚丁二烯-嵌段-聚苯乙烯（SBS）上，以制备一种橡胶状膜，该膜被并入市售电极体中。构建了一个测量单元，该单元包括硝酸根离子选择性电极、参比电极和温度探头，它们通过前置放大器连接到数据记录器和电池电源。开发了一种温度校正算法，以适应排水堰中遇到的温度变化。在0.47-16 ppm硝酸盐氮的浓度范围内，ISE每小时获得的硝酸盐结果与同期排水样品的实验室自动化学测定结果相比非常有利（R2 = 0.99）。ISE不需要重新校准，并且在四个月的部署过程中未观察到性能下降或膜表面污染。
