Absorbance detector and liquid chromatograph

An abnormality determination method to be performed in a liquid chromatograph,

• the liquid chromatograph comprising:
• a sample cell through which a sample solution including a sample flows;
• a light source for irradiating the sample cell with light;
• a photo sensor for detecting intensity of light that has been transmitted through the sample;
• an optical system for guiding the light emitted from the light source to the sample cell and guiding the light that has been transmitted through the sample cell to the photo sensor;
• a reference signal acquirer configured to acquire a detection signal of the photo sensor when the sample solution is not flowing through the sample cell as a reference signal for each analysis of the sample;
• and
• a calculator configured to find absorbance of the sample flowing through the sample cell based on a measurement signal obtained by the photo sensor in the analysis and the reference signal acquired for the analysis when the analysis of the sample is carried out, and
• the abnormality determination method including:
• associating data of the absorbance found by the calculator in the analysis of the sample and data of the reference signal acquired for the analysis to each other for storage;
• finding an increasing or decreasing trend of the absorbance and an increasing or decreasing trend of the reference signal associated with an increase in number of analyses based on the stored absorbance of each analysis and the stored reference signal in a case where an analysis of a same sample is carried out multiple times;
• and
• determining presence or absence of an abnormality in the sample cell, the light source or the optical system based on a combination of the increasing or decreasing trend of the absorbance and the increasing or decreasing trend of the reference signal.