Patent ID: 6867046

Claim:
A method for measuring a concentration of a solution comprising the steps of: (1) mixing an acid in a sample to be detected containing at least protein; (2) heating and opacifying said sample to be detected with said acid mixed; (3) projecting a light on the opacified sample to be detected; (4) detecting a light transmitted through said sample to be detected and/or a light scattered from said sample to be detected out of the projected light; and (5) determining a protein concentration of said sample to be detected based on an intensity of the detected light, wherein said step (2) and said step (3) are performed simultaneously, wherein said opacified sample to be detected contains a spontaneous optical active substance other than protein, said method further comprising a step of: measuring an angle of rotation of said spontaneous optical active substance and said protein in said sample to be detected before mixing said acid in said sample to be detected, and determining a concentration of said spontaneous optical active substance in said sample to be detected.