Abstract: A sample solution is stored in a total reflection cell, and a measuring beam is introduced from an incident optical system to be totally reflected, for measuring a total reflection absorption spectrum. Hydrogen peroxide contained in the sample solution is determined on the basis of absorbance at the position of any absorption peak of the spectrum which is present at 1200 to 1500 cm.sup.-1 or 2600 to 3000 cm.sup.-1. Hydrogen peroxide contained in an aqueous solution can be simply quantitatively analyzed through optical analysis.

Abstract: A cell storing a sample prepared by adsorbing an immunocomplex which is formed by antigen-antibody reaction on a surface of a noble metal colloid such as a gold colloid as an immunity test material is irradiated with excitation light from a light source by an optical system. Raman scattering light generated from the sample is guided to and detected by a spectral detector through an optical system. A signal processing arithmetic unit corrects the Raman scattering light which is detected by the spectral detector with an output of the detector indicating intensity of the light source for obtaining a Raman spectrum, thereby identifying or determining a measuring object material.

Abstract: An excitation beam generated from a light source is separated into a measuring beam and a reference beam by an optical path adjusting optical system including a beam splitter, so that the measuring beam is applied to a sample in a cell. Raman scattering light which is generated from the sample is detected by a spectral detector including a spectroscope through a scattering light path adjusting optical system and a wavelength selector. In a spectrum obtained by the spectral detector, a peak of Raman scattering in which wavenumber shift from the wavelength of the excitation beam is present at 800 to 920 cm.sup.-1 is employed to make quantitative measurement of hydrogen peroxide. Hydrogen peroxide contained in an aqueous solution can be simply quantitatively analyzed through optical analysis means.

Abstract: A cell storing a sample prepared by adsorbing an immunocomplex which is formed by antigen-antibody reaction on a surface of a noble metal colloid such as a gold colloid as an immunity test material is irradiated with excitation light from a light source by an optical system. Raman scattering light generated from the sample is guided to and detected by a spectral detector through an optical system. A signal processing arithmetic unit corrects the Raman scattering light which is detected by the spectral detector with an output of the detector indicating intensity of the light source for obtaining a Raman spectrum, thereby identifying or determining a measuring object material.