Shelar, V.M.Hegde, G.M.Umesh, G.Jagadeesh, G.Reddy, K.P.J.2026-02-052014Spectroscopy Letters, 2014, 47, 1, pp. 12-18387010https://doi.org/10.1080/00387010.2013.775463https://idr.nitk.ac.in/handle/123456789/26670In this paper we report the quantitative oxygen quenching effect on laser-induced fluorescence of acetone, methyl ethyl ketone, and 3-pentanone at low pressures (?700 torr) with oxygen partial pressures up to 450 torr. Nitrogen was used as a bath gas in which these molecular tracers were added in different quantities according to their vapor pressure at room temperature. These tracers were excited by using a frequency-quadrupled, Q-switched, Nd:YAG laser (266 nm). Stern-Volmer plots were found to be linear for all the tracers, suggesting that quenching is collisional in nature. Stern-Volmer coefficients (k<inf>sv</inf>) and quenching rate constants (k<inf>q</inf>) were calculated from Stern-Volmer plots. The effects of oxygen on the laser-induced fluorescence of acetone, methyl ethyl ketone, and 3-pentanone were compared with each other. Further, the Smoluchowski theory was used to calculate the quenching parameters and compared with the experimental results. Copyright © Taylor & Francis Group, LLC.diffusion coefficientfluorescence quenchingketonesLIFoxygen