Patent ID: 6952259

Claim:
A method of detecting the presence of a liquid in a mix, comprising: producing a first mix not containing the liquid to be detected; exciting the first mix by a light signal of wavelength λ; measuring a fluorescence signal S 1 emitted by the first mix over a time Δt close to a lifetime τ 1 characteristic of the liquid to be detected, so as to produce a reference quantity Ro which is a function of the measured signal S 1 ; producing the mix from constituents identical to the constituents making up the first mix and from an amount of the liquid to be detected; exciting the mix by a light signal of wavelength λ; measuring a fluorescence signal S 11 emitted by the mix over the time Δt close to the lifetime τ 1 so as to produce a quantity R which is a function of the measured signal S 11 ; and comparing the quantity R with a quantity k×Ro, wherein k is a coefficient that takes into account the statistical fluctuations of R.