Determination of Dissolved Reactive Phosphorus in Estuarine Waters Using a Reversed Flow Injection Manifold
Determination of Dissolved Reactive Phosphorus in Estuarine Waters Using a Reversed Flow Injection Manifold
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DOI：
10.1039/a705363k
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发表时间：
1997
期刊：
影响因子：
4.2
通讯作者：
Stefan Auflitsch;D. M. Peat;P. Worsfold;I. McKelvie
中科院分区：
文献类型：
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作者：
Stefan Auflitsch;D. M. Peat;P. Worsfold;I. McKelvie
采用常规的流动注射（FI）歧管进样测定河口沃茨中溶解态活性磷时，折射率（RI）效应是一个主要问题。这是因为进样区和载流之间的RI差异会产生叠加在空白响应上的透镜效应，并导致定量中的显著误差。一个简单的反向流动注射（RFI）歧管使用分光光度检测，消除这些定量误差的报告。将酸性溶液注入具有相同折射率的硫酸载体流中，并依次与样品和还原剂（抗坏血酸）合并。将磷钼酸盐还原为磷钼蓝在恒温60 °C的线圈中进行。用去离子水配制的标准溶液成功地测定了河口沃茨中溶解态活性磷，检出限为2 μ gl-1 PO_4-P，线性范围为2-100 μ gl-1 PO_4-P（r ~ 2 = 0.9998）。
The Schlieren or refractive index (RI) effect is a major problem in the determination of dissolved reactive phosphorus in estuarine waters using conventional flow injection (FI) manifolds with sample injection. This is because differences in RI between the injected sample zone and the carrier stream give rise to a lensing effect which is superimposed on the blank response and causes significant error in quantitation. A simple reversed flow injection (rFI) manifold using spectrophotometric detection which removes these quantitation errors is reported. Acidic molybdate is injected into a sulfuric acid carrier stream of the same refractive index and sequentially merged with sample and reductant (ascorbic acid). Reduction of phosphomolybdate to phosphomolybdenum blue is carried out in a coil thermostated at 60 °C. Dissolved reactive phosphorus has been successfully determined in estuarine waters with salinities ranging from 0 to 30‰ using calibration standards prepared in deionized water, with a detection limit of 2 µg l–1 PO4–P and a linear range of 2–100 µg l–1 PO4–P (r2 = 0.9998).