A carbon tetrachloride sensor is presented that is based on a novel approach that involves quenching of the fluorescence emission from the second excited state (S_o $IMP S₂ transition) of a dye, congo red, and an air purge mechanism. The Stern-Volmer plot for the sensor response towards carbon tetrachloride in air is linear over the investigated concentration range, 0 - 5 mM, with a K_sv value of 84.85 M^-1. The detection limit was found to be 47 (mu) M CCl₄ in air. It is suggested that the operating fluorescence quenching process is diffusion controlled and collisional in nature. The sensor is fully reversible with an analytical response time < 25 s and recovery time < 2 s. The environmental applications of this sensor that is capable of providing a reference signal, while in-situ, are discussed.

Date Published: 10 March 1994
PDF: 6 pages
Proc. SPIE 2068, Chemical, Biochemical, and Environmental Fiber Sensors V, (10 March 1994); doi: 10.1117/12.170673

Published in SPIE Proceedings Vol. 2068:
Chemical, Biochemical, and Environmental Fiber Sensors V
Robert A. Lieberman, Editor(s)