Analytical technique
Encyclopedia
An analytical technique is a method that is used to determine the concentration
of a chemical compound
or chemical element
. There are a wide variety of techniques used for analysis, from simple weighing (gravimetric analysis
) to titration
s (titrimetric) to very advanced techniques using highly specialized instrumentation. The most common techniques used in analytical chemistry
are the following:
There are many more techniques that have specialized applications, and within each major analytical technique there are many applications and variations of the general techniques.
Concentration
In chemistry, concentration is defined as the abundance of a constituent divided by the total volume of a mixture. Four types can be distinguished: mass concentration, molar concentration, number concentration, and volume concentration...
of a chemical compound
Chemical compound
A chemical compound is a pure chemical substance consisting of two or more different chemical elements that can be separated into simpler substances by chemical reactions. Chemical compounds have a unique and defined chemical structure; they consist of a fixed ratio of atoms that are held together...
or chemical element
Chemical element
A chemical element is a pure chemical substance consisting of one type of atom distinguished by its atomic number, which is the number of protons in its nucleus. Familiar examples of elements include carbon, oxygen, aluminum, iron, copper, gold, mercury, and lead.As of November 2011, 118 elements...
. There are a wide variety of techniques used for analysis, from simple weighing (gravimetric analysis
Gravimetric analysis
Gravimetric analysis describes a set of methods in analytical chemistry for the quantitative determination of an analyte based on the mass of a solid...
) to titration
Titration
Titration, also known as titrimetry, is a common laboratory method of quantitative chemical analysis that is used to determine the unknown concentration of an identified analyte. Because volume measurements play a key role in titration, it is also known as volumetric analysis. A reagent, called the...
s (titrimetric) to very advanced techniques using highly specialized instrumentation. The most common techniques used in analytical chemistry
Analytical chemistry
Analytical chemistry is the study of the separation, identification, and quantification of the chemical components of natural and artificial materials. Qualitative analysis gives an indication of the identity of the chemical species in the sample and quantitative analysis determines the amount of...
are the following:
- TitrimetryTitrationTitration, also known as titrimetry, is a common laboratory method of quantitative chemical analysis that is used to determine the unknown concentration of an identified analyte. Because volume measurements play a key role in titration, it is also known as volumetric analysis. A reagent, called the...
, based on the quantity of reagent needed to react with the analyteAnalyteAn analyte, or component , is a substance or chemical constituent that is of interest in an analytical procedure. Grammatically, it is important to note that experiments always seek to measure properties of analytes—and that analytes themselves can never be measured. For instance, one cannot...
; - Electroanalytical methodElectroanalytical methodElectroanalytical methods are a class of techniques in analytical chemistry which study an analyte by measuring the potential and/or current in an electrochemical cell containing the analyte. These methods can be broken down into several categories depending on which aspects of the cell are...
s, including potentiometry and voltammetryVoltammetryVoltammetry is a category of electroanalytical methods used in analytical chemistry and various industrial processes. In voltammetry, information about an analyte is obtained by measuring the current as the potential is varied.- Three electrode system :...
; - SpectroscopySpectroscopySpectroscopy is the study of the interaction between matter and radiated energy. Historically, spectroscopy originated through the study of visible light dispersed according to its wavelength, e.g., by a prism. Later the concept was expanded greatly to comprise any interaction with radiative...
, based on the interaction of the analyte with electromagnetic radiationElectromagnetic radiationElectromagnetic radiation is a form of energy that exhibits wave-like behavior as it travels through space...
; - ChromatographyChromatographyChromatography is the collective term for a set of laboratory techniques for the separation of mixtures....
, in which the analyte is separated from the rest of the sample so that it may be measured without interference from other compounds; - MicroscopyMicroscopyMicroscopy is the technical field of using microscopes to view samples and objects that cannot be seen with the unaided eye...
; - BioanalysisBioanalysisBioanalysis is a sub-discipline of analytical chemistry covering the quantitative measurement of xenobiotics and biotics in biological systems.-Modern bioanalytical chemistry:Many scientific endeavors are dependent upon...
; - Radioanalytical chemistryRadioanalytical chemistryRadioanalytical chemistry focuses on the analysis of sample for their radionuclide content. Various methods are employed to purify and identify the radioelement of interest through chemical methods and sample measurement techniques.- History :...
;
There are many more techniques that have specialized applications, and within each major analytical technique there are many applications and variations of the general techniques.