Fluorescence spectrophotometer

A liquid chromatograph system, comprising a fluorescence spectrophotometer and a separation column, the fluorescence spectrophotometer including:

• a light source;
• a sample cell;
• an excitation-side light-dispersing system for dispersing a light from the light source and for casting a desired wavelength of light into the sample cell;
• an emission-side light-dispersing system for dispersing a light emitted from the sample cell, the emission-side light-dispersing system being located off an optical path of a transmitted light exiting from the sample cell after being cast from the excitation-side light-dispersing system into the sample cell;
• a photodetector capable of detecting, among the light from the emission-side light-dispersing system, an emission light having a same wavelength as the light cast from the excitation-side light-dispersing system into the sample cell;
• a controller for continuously varying a set wavelength of the excitation-side light-dispersing system and a set wavelength of the emission-side light-dispersing system over a predetermined wavelength range while keeping the two wavelengths equal to each other;
• and
• a spectrum data acquirer for obtaining spectrum data from detection results obtained with the photodetector for each of the set wavelengths of the excitation-side light-dispersing system and the emission-side light-dispersing system,
• wherein:
• a sample separated into components by the separation column is passed through the sample cell together with a mobile phase;
• and
• the spectrum data acquirer obtains data on a temporal change of a spectrum for each of the set wavelengths.

A method for detecting an excitation wavelength in a fluorescence spectrophotometer having:

• a light source;
• a sample cell;
• an excitation-side light-dispersing system for dispersing a light from the light source and for casting a desired wavelength of light into the sample cell;
• an emission-side light-dispersing system for dispersing a light emitted from the sample cell, the emission-side light-dispersing system being located off an optical path of a transmitted light exiting from the sample cell after being cast from the excitation-side light-dispersing system into the sample cell;
• and
• a photodetector capable of detecting, among the light from the emission-side light-dispersing system, an emission light having a same wavelength as the light cast from the excitation-side light-dispersing system into the sample cell,
• the method comprising steps of:
• continuously varying a set wavelength of the excitation-side light-dispersing system and a set wavelength of the emission-side light-dispersing system over a predetermined wavelength range while keeping the two wavelengths equal to each other;
• obtaining spectrum data from detection results obtained with the photodetector for each of the set wavelengths of the excitation-side light-dispersing system and the emission-side light-dispersing system;
• and
• detecting an excitation wavelength of a sample from the obtained spectrum data.