Analytical Sciences

Determination of Trace Iron in the Boiler Water Used in Power Generation Plants by Solid-phase Spectrophotometry

SARENQIQIGE,* Akihiro MAEDA,** and Kazuhisa YOSHIMURA*

*Department of Chemistry, Faculty of Sciences, Kyushu University, Hakozaki, Higashi, Fukuoka 812-8581, Japan
**Energy and Environment, Mitsubishi Heavy Industries, Ltd., Wadasaki-cho, Hyogo, Kobe 652-8585, Japan

A sensitive, simple and low-cost determination method for the total iron concentration in boiler water systems of power generation plants was developed by solid phase spectrometry (SPS) using 2,4,6-tris(2-pyridyl)-1,3,5-triazine (TPTZ) as a coloring agent. The reagents and 0.08 cm³ of a cation exchanger were added to a 50-cm³ boiler water sample, then mixed for 30 min to adsorb/concentrate the produced Fe(TPTZ)₂²⁺ colored complex on the solid beads, resulting in a 625 times concentration of the target analyte without any other procedure. The detection limit of 0.1 μg dm⁻³ was obtained, and the optimum conditions for the digestion procedure and color developing reaction was investigated and reported. According to the application of this method to real samples, the present SPS method is the best one because of the shorter analysis time, simpler operation and use of very low-cost equipment compared to the conventional methods, such as TPTZ solution spectrophotometric method after a 16 times concentration, ICP-MS and AAS.

J-STAGE: View this article in J-STAGE