Analytical Sciences


Abstract − Analytical Sciences, 20(6), 975 (2004).

A Simple and Portable Colorimeter Using a Red-Green-Blue Light-Emitting Diode and Its Application to the On-Site Determination of Nitrite and Iron in River-water
Yasutada SUZUKI, Terutomi ARUGA, Hiroyuki KUWAHARA, Miki KITAMURA, Tetsuo KUWABARA, Susumu KAWAKUBO, and Masaaki IWATSUKI
Department of Applied Chemistry and Biotechnology, Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi 4-3-11, Takeda, Kofu, Yamanashi 400-8511, Japan
A portable colorimeter using a red-green-blue light-emitting diode as a light source has been developed. An embedded controller sequentially turns emitters on and off, and acquires the signals detected by two photo diodes synchronized with their blinking. The controller calculates the absorbance and displays it on a liquid-crystal display. The whole system, including a 006P dry cell, is contained in a 100 × 70 × 50 mm aluminum case and its mass is 280 g. This colorimeter was successfully applied to the on-site determination of nitrite and iron in river-water.