Abstract
An optical fiber sensor for the continuous determination of hydrochloric acid is presented. It is based on the fluorescence quenching of a flavone containing copolymer membrane by hydrochloric acid. The quenching efficiency is greatly enhanced in the presence of Fe(III). This enhancement is attributed to the primary inner filter effect, as well as the formation of a complex between the 4′-N,N-dimethylaminoflavone group in the copolymer and the Fe(III) species extracted from hydrochloric acid solution. The optical response is linear and reversible for 0.10–6.00 mol L–1 HCl with a response time of the order of a second. The standard deviations for repeated alternative measurements of 0.20 and 2.00 mol L–1 hydrochloric acid are 0.32% and 0.46% (n = 10), respectively, indicating a good reproducibility. Because of the covalently bonding of the dye to polymer, the sensor exhibits also a good stability. Selectivity has also been evaluated for some potential interferents. The sensor in conjunction with a flow-injection system can be used for on-line determination of hydrochloric acid.
Similar content being viewed by others
Author information
Authors and Affiliations
Additional information
Received: 15 January 1998 / Revised: 14 April 1998 / Accepted: 18 April 1998
Rights and permissions
About this article
Cite this article
Liu, W., Tang, J., Wang, Y. et al. Optosensing of hydrochloric acid based on the fluorescence quenching of a flavone copolymer. Fresenius J Anal Chem 362, 387–390 (1998). https://doi.org/10.1007/s002160051090
Issue Date:
DOI: https://doi.org/10.1007/s002160051090