Analytical Sciences

Abstract − Analytical Sciences, 21(3), 263 (2005).

Trace and Ultratrace Analysis of Purified Water Samples and Hydrogen Peroxide Solutions for Phosphorus by Flow-Injection Method
Zenhai LI, Mitsuko OSHIMA, Akhmad SABARUDIN, and Shoji MOTOMIZU
Department of Chemistry, Faculty of Science, Okayama University, Tsushimanaka 3-1-1, Okayama 700-8530, Japan
A highly sensitive fluorescence-quenching method for the determination of phosphorus based on the formation of an ion associate between molybdophosphate and Rhodamine B (RB) was developed. A simple flow-injection system coupled with a fluorescence detector was used to measure the fluorescence intensity at 560 nm and 580 nm as an excitation and an emission wavelength, respectively. The calibration graph for phosphorus showed a good linearity in the range of (0 - 1) × 10-7 M (1 M = 1 mol L-1), and a detection limit of 1 × 10-9 M (S/N = 3). The proposed method was successfully applied to the determination of ultratrace amounts of phosphorus in ultrapurified and purified water samples, and to the determination of trace amounts of phosphorus in commercially-available hydrogen peroxide solutions with satisfactory results.