standardikäyrä

Standardikäyrä, also known as a calibration curve or standard curve, is a graph used in analytical chemistry and related fields to determine the concentration of an unknown analyte. It is created by plotting the known concentrations of a series of standard solutions against their corresponding measured responses, such as absorbance, fluorescence, or peak area in chromatography. The relationship between concentration and response is typically assumed to be linear within a certain range.

To construct a standardikäyrä, several solutions with accurately known concentrations of the substance of interest are prepared. These solutions are then subjected to the same analytical procedure as the unknown sample. The resulting measurements are plotted on a graph, with concentration on the x-axis and the measured response on the y-axis. A line of best fit is then drawn through these data points, often using linear regression.

Once the standardikäyrä is established, the measured response of an unknown sample can be used to determine its concentration. The measured response is located on the y-axis of the graph, and the corresponding concentration is read off the x-axis by tracing a line from the measured response to the line of best fit and then down to the x-axis. Standardikäyrät are essential for quantitative analysis, ensuring accuracy and reliability in various scientific disciplines. They are widely used in medical diagnostics, environmental monitoring, and quality control.