Analytical technique is a method used to determine a chemical or physical property of a
chemical substance
A chemical substance is a form of matter having constant chemical composition and characteristic properties. Some references add that chemical substance cannot be separated into its constituent Chemical element, elements by physical separation m ...
,
chemical element
A chemical element is a species of atoms that have a given number of protons in their nuclei, including the pure substance consisting only of that species. Unlike chemical compounds, chemical elements cannot be broken down into simpler sub ...
, or mixture. There is a wide variety of techniques used for analysis, from simple weighing to advanced techniques using highly specialized instrumentation.
Classical methods of analysis
Classical analysis methods involve basic analytical methods widely used in laboratories.
Gravimetric analysis
Gravimetric analysis describes a set of methods used in analytical chemistry
Analytical chemistry studies and uses instruments and methods to separate, identify, and quantify matter. In practice, separation, identification or quantificati ...
measures the weight of the sample.
Titrimetry is a technique used to determine the concentration of the analyte.
Spectrochemical analysis
Spectrometer
A spectrometer () is a scientific instrument used to separate and measure spectral components of a physical phenomenon. Spectrometer is a broad term often used to describe instruments that measure a continuous variable of a phenomenon where th ...
can determine chemical composition through its measure of spectrums. The common spectrometer used in analytical chemistry is
Mass spectrometry
Mass spectrometry (MS) is an analytical technique that is used to measure the mass-to-charge ratio of ions. The results are presented as a '' mass spectrum'', a plot of intensity as a function of the mass-to-charge ratio. Mass spectrometry is u ...
. In a mass spectrometer, a small amount of sample is ionized and converted to gaseous ions, where they are separated and analyzed according to their
mass-to-charge ratios.
Electroanalytical analysis
Electroanalytical methods utilize the potential or current of a
electrochemical cell
An electrochemical cell is a device capable of either generating electrical energy from chemical reactions or using electrical energy to cause chemical reactions. The electrochemical cells which generate an electric current are called voltaic o ...
. The three main sections of this type of analysis are
potentiometry,
coulometry and
voltammetry. Potentiometry measures the cell's potential, coulometry measures the cell's current, and voltammetry measures the change in current when cell potential changes.
Chromatography
Chromatography
In chemical analysis, chromatography is a laboratory technique for the separation of a mixture into its components. The mixture is dissolved in a fluid solvent (gas or liquid) called the ''mobile phase'', which carries it through a system ( ...
separates the analyte from the rest of the sample so that it may be measured without interference from other compounds.
There are different types of chromatography that differ from the media they use to separate the analyte and the sample.
In
Thin-layer chromatography
Thin-layer chromatography (TLC) is a chromatography technique used to separate non-volatile mixtures.
Thin-layer chromatography is performed on a sheet of an inert substrate such as glass, plastic, or aluminium foil, which is coated with a t ...
, the analyte mixture moves up and separates along the coated sheet under the volatile mobile phase. In
Gas chromatography
Gas chromatography (GC) is a common type of chromatography used in analytical chemistry for separating and analyzing compounds that can be vaporized without decomposition. Typical uses of GC include testing the purity of a particular substance, ...
, gas separates the volatile analytes. A common method for chromatography using liquid as a mobile phase is
High-performance liquid chromatography
High-performance liquid chromatography (HPLC), formerly referred to as high-pressure liquid chromatography, is a technique in analytical chemistry used to separate, identify, and quantify each component in a mixture. It relies on pumps to pa ...
.
See also
*
List of chemical analysis methods
*
List of materials analysis methods
This is a list of analysis methods used in materials science. Analysis methods are listed by their acronym, if one exists.
Symbols
* μSR – see muon spin spectroscopy
* χ – see magnetic susceptibility
A
* AAS – Atomic absorption spe ...
*
Microanalysis
*
Ion beam analysis Ion beam analysis ("IBA") is an important family of modern analytical techniques involving the use of MeV ion beams to probe the composition and obtain elemental depth profiles in the near-surface layer of solids. All IBA methods are highly sensi ...
*
Rutherford backscattering spectroscopy
*
Nuclear reaction analysis
*
Radioanalytical chemistry Radioanalytical 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
T ...
*
Calorimeter
References
Analytical chemistry
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