Abstract: A laser-induced fluorescence analysis device (1), comprising a tube (2) including a channel, elements projecting an excitation light (13), optical collecting member (7), optical measurement elements (8) and a processing member (9) for producing an analysis result, the collecting member being mechanically coupled to one end of the channel, the tube being integrally made of a material with refractive index either lower than that of water, or higher than both that of water and that of ambient air so as to guide the fluorescence light along the channel in the channel and/or its wall up to the collecting member, which is designed to collect the fluorescence light propagated along the longitudinal direction of the channel.

Abstract: A method for detecting traces of pollutant in aqueous media, wherein the method includes the use of isocyanates to react on the nucleophilic functions in the form of trace amounts in a wet medium. The method for assaying nulceophilic functions in a wet medium includes the following steps: adding isocyanates to an aqueous solution of basic pH containing the nucleophilic functions to be tested; maintaining the solution for an interval ranging from a few minutes to several dozens of minutes at a temperature lower than 100° C.; and assaying the resulting carbamate, thiocarbamate or urea.