Sequential injection trace determination of iron in natural waters using a long-pathlength liquid core waveguide and different spectrophotometric chemistries

摘要

We developed a sequential injection analysis (SIA) method for the determination of iron in coastal, ground,and surface fresh waters using two different reagents (ferrozine and 1,10-phenathroline). The methodology usesa double-line SIA system to improve mixing conditions between sample and reagent solutions. A liquid waveguidecapillary cell (LWCC) with 1.0 m pathlength, 550 μm i.d., and 250 μL internal volume was used toenhance the sensitivity of the determination. The detection limits for the ferrozine and 1,10-phenanthrolinereagent were 0.15 and 0.35 μg L–1, respectively. The system provides a linear response up to 20 μg L–1 and has ahigh throughput rate (41 h–1), low reagent consumption, and also low effluent production for both reagents.The developed method was applied to natural waters (river, well, ground, potable, and sea waters) and one referencewater sample.