摘要:
A method for detecting a photochemically active chemical species in a sample, comprising the steps of: a) illuminating the sample with light at a wavelength suitable to trigger a reaction affecting an optical property of the chemical species according to an illumination sequence, such that: • in at least a first time window, the kinetics of the first reaction is limited by a photochemically-activated step of the reaction; and • in at least a second time window, the kinetics of the first reaction is limited by a thermally-activated step;
b) measuring the evolution of the optical property during the first and the second time windows; c) determining at least a first and a second time constant representing the kinetics of the first reaction in the first and the second time windows, respectively; and d) using the determined time constants for identifying the chemical species. An apparatus for carrying out such a method.
摘要:
Method for detection of at least one reversibly photo-convertible fluorescent species (P), comprising the following steps: a) illumination of a sample comprising said or at least one of said reversibly photo-convertible fluorescent species by a periodically modulated illuminating light (FEX); and b) detection of fluorescent radiation (FLU) emitted by the sample thus illuminated; characterised in that the method further comprises the following step: c) extraction of the amplitude (lF0Ut) of the intensity component of said fluorescent radiation exhibiting the same periodicity as said periodically modulated illuminating light and a phase quadrature with respect to the same; and in that the mean intensity of said illuminating light and the modulation frequency of the same are chosen in such a way as to maximise said amplitude of the intensity component of said fluorescent radiation.
摘要:
This process comprises the choice of a supposed reaction mechanism of a reaction, the selection for said mechanism of at least one first function characteristic of a thermokinetic quantity that is invariant with the frequency of periodic variation of a control parameter that has an influence on said reaction, the first characteristic function being calculated at least from first-order oscillation amplitudes of the concentration of at least one of the species involved in said reaction. The process comprises the calculation of a plurality of values of the first characteristic function from first-order oscillation amplitudes obtained experimentally. It comprises an analysis of the calculated values of the first characteristic function in order to determine if the first characteristic function is constant on the basis of the calculated values and when the first characteristic function is constant, the attribution of the supposed mechanism to said reaction.
摘要:
The subject of the present invention is a method for determining the hydrodynamic range of the constituents of a mixture, in which: (A) by capillary electrophoresis, the constituents of the mixture M are separated, leaving them within the capillary; (B) at one of the ends of the capillary thus obtained, containing, in various zones, the constituents separated in step (A), a marker is injected that can be detected by a detection device placed on the side facing the other end of the capillary; (C) a pressure difference is induced between the ends of the capillary so as to make the various constituents separated during step (A) and, finally, the marker migrate towards the outlet of the capillary; and (D) the hydrodynamic range of each of said constituents is determined, by analysing the Taylor dispersion produced in step (C), from the time at which the marker is detected and from the elution profile of each of the constituents.