Flow injection analysis combined with a hydrothermal flow reactor: Application to kinetic determination of trace amounts of iridium using a water-soluble porphyrin

Kunio Kawamura, Keisuke Ikoma, Shukuro Igarashi, Hideaki Hisamoto, Toshio Yao

Index: Talanta 84(5) , 1318-22, (2011)

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Abstract

A new type of flow injection analysis (FIA) system combined with an extremely high temperature reactor, namely hydrothermal flow injection analysis (HT-FIA), has been successfully constructed for the first time. Fundamental characteristics of HT-FIA system, such as limit temperature, pressure, and flow rate, were examined as an analytical tool. To demonstrate the potential of HT-FIA, the catalytic activity of Ir(IV) for the degradation of a water-soluble porphyrin, 5,10,15,20-tetraphenyl-21H,23H-porphinetetrasulfonic acid (TPPS), was applied for the determination of trace amounts of Ir(IV). Although the indicator reaction is very slow at room temperature, HT-FIA system enables to accelerate the reaction. A linear calibration curve was acquired at 10−8M level of Ir(IV) and the interferences of platinum group metal ions were examined. The detection limit of Ir(IV) was 5.8×10−9M and a fairly high-throughput analysis, of which more than 30 samples can be analyzed within 80min, was achieved.