Method and system for spectrophotometric analysis of a sample

A method for the spectrophotometric analysis of a sample of a liquid solution in a measurement chamber, wherein said measurement chamber is selectively in fluid communication with a duct of an hydraulic circuit in which said liquid solution flows, said measurement chamber delimiting at least one inlet opening and at least one outlet opening, in which the at least one inlet opening is configured so that at least one substantially monochromatic beam, configured to be generated by at least one voltage controllable emitting device through at least one excitation voltage Vin between one minimum value Vin_min and one maximum value Vin_max, enters the measurement chamber and is transmitted along one optical path of said measurement chamber, and the at least one outlet opening is configured so that said at least one substantially monochromatic beam exits the measurement chamber at the end of the optical path and can be detected by at least one detecting device configured for the detection of said at least one substantially monochromatic beam, the method comprising the following steps of:

• B0. supplying said at least one sample of said liquid solution into said measurement chamber from said duct of the hydraulic circuit, with which said measurement chamber is selectively in fluid communication;
• B. mixing said at least one sample of said liquid solution with a corresponding reagent substance in said measurement chamber;
• C. generating at least one substantially monochromatic beam of luminous intensity Iin and wavelength λ0, wherein said wavelength λ0 corresponds to one compound obtained by the reaction of a substance of interest to be quantified, contained in said sample of said thus mixed liquid solution with said corresponding reagent substance;
• D. illuminating, by means of said at least one emitting device, said sample of said thus mixed liquid solution, with said at least one substantially monochromatic beam, through said at least one inlet opening of said measurement chamber, along said optical path;
• E. detecting said at least one substantially monochromatic beam, at the end of said optical path, through said at least one outlet opening of said measurement chamber;
• and
• F. processing said at least one substantially monochromatic beam thus detected, to determine the concentration of the said substance to be quantified;
• wherein
• said at least one substantially monochromatic beam is generated at said at least one inlet opening of said measurement chamber, and said at least one substantially monochromatic beam is detected at said at least one outlet opening of said measurement chamber, so that said optical path has a length substantially corresponding to the linear distance between said at least one inlet opening and said at least one outlet opening and wherein said method comprises
• one step A2, preliminary to said step C, for the determination of the luminous intensity Iin of said substantially monochromatic beam, based on the cleaning state of said measurement chamber and/or ageing of said at least one emitting device and/or ageing of said at least one detecting device, whereby the worse is the cleaning state of said measurement chamber and/or the greater is the ageing state of said at least one emitting device and/or said at least one detecting device, the higher is the luminous intensity Iin of said substantially monochromatic beam.

A system for the spectrophotometric analysis of a sample of a liquid solution in a measurement chamber, wherein said measurement chamber is selectively in fluid communication with a duct of an hydraulic circuit in which said liquid solution flows and delimits at least one inlet opening and at least one outlet opening, in which the at least one inlet opening is configured so that at least one substantially monochromatic beam enters the measurement chamber and is transmitted along one optical path of said measurement chamber, and the at least one outlet opening is configured to ensure that said at least one substantially monochromatic beam exits the measurement chamber at the end of the optical path, the system comprising:

• at least one supplying group of said sample of liquid solution, configured to supply said sample of said liquid solution into said measurement chamber, from said duct of said hydraulic circuit;
• at least one emitting device, configured for generating said substantially monochromatic beam at said at least one inlet opening of said measurement chamber and emitting said substantially monochromatic beam at said at least one inlet opening of said measurement chamber, along said optical path;
• at least one feeding group of one reagent substance into said at least one measurement chamber, configured for feeding and mixing said at least one reagent substance in said at least one measurement chamber;
• at least one detecting device, configured for detecting said substantially monochromatic beam at said at least one outlet opening of said measurement chamber, a the end of said optical path;
• at least one control and processing unit, operatively connected to said at least one emitting device and said at least one detecting device and said at least one feeding group, and configured together with said at least one emitting device, said at least one detecting device, and to said at least one feeding group to carry out a method comprising the following steps of:
• B0. supplying said at least one sample of said liquid solution into said measurement chamber from said duct of the hydraulic circuit, with which said measurement chamber is selectively in fluid communication;
• B. mixing said at least one sample of said liquid solution with a corresponding reagent substance in said measurement chamber;
• C. generating at least one substantially monochromatic beam of luminous intensity Iin and wavelength λ0, wherein said wavelength λ0 corresponds to one compound obtained by the reaction of a substance of interest to be quantified, contained in said sample of said thus mixed liquid solution with said corresponding reagent substance;
• D. illuminating, by means of said at least one emitting device, said sample of said thus mixed liquid solution, with said at least one substantially monochromatic beam, through said at least one inlet opening of said measurement chamber, along said optical path;
• E. detecting said at least one substantially monochromatic beam, at the end of said optical path, through said at least one outlet opening of said measurement chamber;
• and
• F. processing said at least one substantially monochromatic beam thus detected, to determine the concentration of the said substance to be quantified;
• wherein
• said at least one substantially monochromatic beam is generated at said at least one inlet opening of said measurement chamber, and said at least one substantially monochromatic beam is detected at said at least one outlet opening of said measurement chamber, so that said optical path has a length substantially corresponding to the linear distance between said at least one inlet opening and said at least one outlet opening and
• in that it comprises
• one step A2, preliminary to said step C, for the determination of the luminous intensity Iin of said substantially monochromatic beam, based on the cleaning state of said measurement chamber and/or ageing of said at least one emitting device and/or ageing of said at least one detecting device, whereby the worse is the cleaning state of said measurement chamber and/or the greater is the ageing state of said at least one emitting device and/or said at least one detecting device, the higher is the luminous intensity Iin of said substantially monochromatic beam.