Table of Contents
ISRN Spectroscopy
Volume 2012, Article ID 975716, 5 pages
Research Article

Microdetermination of Methenamine in the Presence of Formaldehyde by Solid Phase Spectrophotometry

1Department of Chemistry, Payame Noor University, P.O. Box 19395-3697, Tehran, Iran
2Department of Chemistry, Tarbiat Modares University, P.O. Box 14115-175, Tehran, Iran

Received 23 October 2012; Accepted 11 November 2012

Academic Editors: R. Fausto, S.-Y. Lin, and M. Mączka

Copyright © 2012 Mehdi Taghdiri et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


A sensitive spectrophotometric method for the determination of methenamine has been developed without any separation steps. Bromocresol green is adsorbed on Sephadex LH-20 gel but the sorption decreases in the presence of methenamine due to ion-pair formation between bromocresol green and methenamine in solution. This attenuation was used to the microdetermination of methenamine by measurement of absorbance of the solid phase (Sephadex LH-20 gel) in a 1.0 mm cell at 625 nm. Methenamine could be determined in the concentration range of 0.42–1.68 μg mL−1 (10-mL Sample volume) with a relative standard deviation (RSD) of 0.03% ( ). The detection limit obtained was 50 μg L−1 for 10 mL sample volume. The method was used for determination of methenamine in industrial wastewater and a satisfactory result was obtained.