Spectral analysis method, analysis apparatus and analysis program

A spectral analysis apparatus comprising:

• a spectral measurement apparatus configured to optically measure a sample in which three or more types of chemical species coexist,
• a Multivariate Curve Resolution (MCR) executing processor that is configured to acquire a measurement spectrum of a plurality of measurement spectra, that is represented as a linear combination of the same number of pure spectra as the number of components, using concentration values of the pure spectra as coefficients, which separates the same number of pure spectra as the number of components from the plurality of measurement spectra and calculates the concentration value of each pure spectrum, and
• a constraint condition setting processor that sets a constraint condition of the concentration value used for Multivariate Curve Resolution-Alternating Least Squares (MCR-ALS) in the MCR executing processor,
• wherein:
• the constraint condition setting processor is configured to set an equilibrium model corresponding to an equilibrium state of the sample, and set at least one chemical-equilibrium equation corresponding to the equilibrium model, and
• the MCR executing processor is configured to repeat processes (A) and (B) to acquire a thermodynamic parameter, the pure spectra and the concentration value of each pure spectrum corresponding to the equilibrium model,
• wherein:
• (A) is a process of acquiring an optimal value of the thermodynamic parameter that configures the chemical-equilibrium equation by fitting a concentration curve based on the chemical-equilibrium equation to the calculated concentration value of each pure spectrum, and
• (B) is a process of acquiring a new concentration value from the chemical-equilibrium equation using the optimal value of the thermodynamic parameter, separating the pure spectra by using the new concentration value and calculating the concentration value of each pure spectrum corresponding to the equilibrium model.

A non-transitory computer-readable storage medium having a spectral analysis program for spectrally analyzing a plurality of measurement spectra by using Multivariate Curve Resolution (MCR) method stored therein, the spectral analysis program causing a computer to execute a process of:

• acquiring a measurement spectrum of the plurality of measurement spectra by optically measuring a sample in which three or more types of chemical species coexist,
• acquiring a measurement spectrum of the plurality of measurement spectra that is represented as a linear combination of the same number of pure spectra as the number of components, using concentration values of the pure spectra as coefficients,
• setting an equilibrium model corresponding to an equilibrium state of the sample,
• setting at least one chemical-equilibrium equation corresponding to the equilibrium model, and
• applying the MCR method to the plurality of measurement spectra, wherein the applying the MCR method to the plurality of measurement spectra comprises:
• separating the same number of pure spectra as the number of components from the plurality of measurement spectra,
• calculating the concentration value of each pure spectrum, and
• repeating processes (A) and (B) to acquire a thermodynamic parameter, the pure spectra and the concentration value of each pure spectrum corresponding to the equilibrium model,
• wherein:
• (A) is a process of acquiring an optimal value of the thermodynamic parameter that configures the chemical-equilibrium equation by fitting a concentration curve based on the chemical-equilibrium equation to the calculated concentration value of each pure spectrum, and
• (B) is a process of acquiring a new concentration value from the chemical-equilibrium equation using the optimal value of the thermodynamic parameter, and separating the pure spectra by using the new concentration value and calculating the concentration value of each pure spectrum corresponding to the equilibrium model.