Quantitative analysis (chemistry)
A quantitative analysis is a chemical and / or physical process which is concerned with answering the question of how much of a substance is present in a given sample.
All methods can be divided into the "classical" and the physical methods of analysis.
In the classical methods it comes to chemical reactions by which a mass, molar and volume determination is made. About stoichiometric conversion factors can then determine the masses of the individual elements. Due to the measurement types, therefore it has the following subcategories:
- Gravimetry or gravimetric analysis elemental analysis
- Acid -base titration
- Redox titration
- Precipitation reaction
In the physical methods, concerns the measurement of the concentration-dependent physical properties, from which the concentration or mass can be calculated.
- Electroanalytical Methods: Conductometry (measurement of the conductivity of an electrolyte solution)
- Spectroscopic methods use the interaction of electromagnetic radiation with the molecules of the sample. photometry
- Colorimetry (measurement of the absorbed light )
- Atomic Spectroscopy
- X-ray fluorescence analysis
- Nuclear methods Neutron Activation Analysis
Among the methods in which both chemical reactions and physical processes play a role include:
- Chromatography with the sub-groups: liquid chromatography
- Gas chromatography
- Qualitative analysis mainly of organic substances in environmental samples
- Structure elucidation of organic substances
- Highly sensitive detection method in chromatography.
- Proteomics and there with the methods iTRAQ
- Electrogravimetry ( measurement of the weight, the electro-deposition )
- Potentiometry ( measuring the potential change )
- Amperometry ( measurement of electrolytic current at constant potential )
- Coulometry (measurement of the required electrical charge )
- Voltammetry ( measurement of current in the known potential )
- Polarography ( voltammetry at a dropping mercury electrode)
- 2D -PAGE (two-dimensional gel electrophoresis)