Analytical Sciences

Abstract − Analytical Sciences, 20(1), 139 (2004).

A Simple and Sensitive Method for the Determination of Hydroxylamine in Fresh-Water Samples Using Hypochlorite Followed by Gas Chromatography
Yasushi SEIKE,*  Ryoko FUKUMORI,* Yukiko SENGA,** Hiroki OKA,* Kaoru FUJINAGA,* and Minoru OKUMURA*
*Faculty of Science and Engineering, Shimane University, 1060, Matsue, Shimane 690-8504, Japan
**Faculty of Life and Environmental Science, Shimane University, 1060, Matsue, Shimane 690-8504, Japan
A new and simple method for the determination of hydroxylamine in environmental water, such as fresh rivers and lakes using hypochlorite, followed by its gas choromatographic detection, has been developed. A glass vial filled with sample water was sealed by a butyl-rubber stopper and aluminum cap without head-space, and then sodium hypochlorite solution was injected into the vial through a syringe to convert hydroxylamine to nitrous oxide. The head-space in the glass vial was prepared with 99.9% grade N2 using a gas-tight syringe. After the glass vial was shaken for a few minutes, nitrous oxide in the gas-phase was measured by a gas chromatograph with an electron-capture detector. The dissolved nitrous oxide in the liquid-phase was calculated according to the solubility formula. The proposed method was applied to the analysis of fresh-water samples taken from Iu river and Hii river, flowing into brackish Lakes Nakaumi and Shinji, respectively.