Kalibreerimiskõvera

Kalibreerimiskõver, also known as a calibration curve or standard curve, is a graph used in analytical chemistry to determine the concentration of a substance in an unknown sample. It is generated by plotting the measured signal from a series of samples with known concentrations (standards) against their corresponding concentrations. The instrument or method used to measure the signal is typically an analytical technique such as spectrophotometry, chromatography, or mass spectrometry.

The process of creating a kalibreerimiskõver involves preparing a set of solutions with accurately known concentrations of the analyte of interest. These solutions, called standards, are then analyzed using the chosen method, and the resulting signal is recorded for each standard. Once the data is collected, the concentration of each standard is plotted on the x-axis and the corresponding signal on the y-axis. A line or curve is then fitted to these data points, often using linear regression if the relationship is linear.

Once the kalibreerimiskõver is established, an unknown sample is analyzed using the same method, and its signal is measured. By locating this signal on the y-axis of the kalibreerimiskõver and tracing across to the fitted line or curve, and then down to the x-axis, the concentration of the analyte in the unknown sample can be determined. The accuracy of the determined concentration depends heavily on the quality of the standards, the precision of the measurements, and the goodness of fit of the calibration curve.