9.6 : 定量分析

Quantitative analysis determines the quantity of one or more constituents of a sample, whose composition is often known. If not, a preliminary qualitative analysis is undertaken to identify its constituents.

In quantitative analysis, the result is estimated from two measurements – the quantification of the sample and the measurement of a quantity related to the analyte proportionately.

Quantitative analysis can be classified into classical and instrumental methods.

The classical methods evaluate the mass or volume of the analyte or its derivative obtained via a chemical reaction with a reagent. In contrast, instrumental methods probe the physical nature of the analyte in its interaction with electromagnetic radiation.

As different samples and instruments are used for quantitative analysis, the calibration of detectors is necessary. Then, a calibration plot is constructed using cuvettes containing different known quantities of the same analyte, which then helps determine the unknown analyte concentration in the sample.