Linear regression is a commonly used method to establish a quantitative relationship between two variables (e.g. the absorbance at a specific wavelength and the concentration of a particular compound). In the case of chemical analysis there is a special condition, which prohibits, for example, negative concentrations of a given substance. Knowing this fact one can determine the detection limit. The detection limit, or LOD (limit of detection), is the lowest quantity of a substance that can be distinguished from the absence of that substance (a blank value) within a stated confidence limit (generally 1%).

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English version	[747 kB]
After downloading please unpack all files of the zipped packages and start the executable.

This program allows to calculate the regression parameters and the limit of detection for two linear scenarios (with and without offset of the measured variable). The user enters the calibration values into the table at the left and immediately sees the results.
Many thanks to Ihor Patsay, Ivan Franko National University of L’viv, Ukraine, who contributed this linear regression tool for chemists to the Learning by Simulations Web site.