tilavuusvaihtelumenetelmillä

Tilavuusvaihtelumenetelmillä, often translated as "variable volume methods" or "dilution techniques," refers to a group of analytical chemistry methods used to determine the concentration of a substance in a solution by adding a known volume of a diluent. The core principle is that the initial concentration of the analyte is unknown, and by diluting it with a precisely measured volume of a solvent or a solution containing a known concentration of the same analyte, the final concentration can be calculated based on the dilution factor.

These methods are particularly useful when the original concentration of the substance is too high to be accurately measured by a particular analytical instrument or technique. By diluting the sample, the concentration is brought into a measurable range. The simplest form involves diluting the sample with a pure solvent. In more complex variations, a "spiking" solution containing a known amount of the analyte is added. This is often referred to as the standard addition method.

The calculation typically involves comparing the signal from the diluted or spiked sample to the signal from a known standard. The dilution factor is crucial, and it is calculated as the ratio of the final volume to the initial volume. For standard addition, the increase in signal after adding the known amount of analyte is used to extrapolate back to the original concentration of the sample. These techniques are widely applied in various fields, including environmental analysis, pharmaceutical quality control, and clinical chemistry. They are valued for their simplicity and effectiveness in handling samples with high analyte concentrations.