EVISA is providing a list of terms used in the area of speciation and fractionation analysis. Since speciation analysis is a field of analytical chemistry that is specified by a pronounced interdisciplinary cooperation between different sciences such as biochemistry, medicine, biology, environmental sciences, nutritional sciences and material sciences its terminology is a complex mixture of terms used in all these.
You may search for a term or browse the glossary alphabetically.
(In case that you cannot find the term you may consult more special glossaries or handbooks about nomenclature. For more details please consult EVISA's List of Glossaries)
Ebselen or 2-phenyl-1, 2-benzisoselenazol-3(2H)-one (also called PZ 51 or DR3305), is a mimic of glutathione peroxidase and can also react with peroxynitrite. It is being investigated as a possible treatment for reperfusion injury and stroke, as well as tinnitus.
Ebselen is a potent scavenger of hydrogen peroxide as well as hydroperoxides including membrane bound phospholipid and cholesterylester hydroperoxides.
Chemical formula: C13H9NOSe Molecular mass: 274.17666 CAS-Number: 60940-34-3
The electric sector is a device constructed of curved, parallel metal plates that creates an electrostatic field perpendicular to the ion path. The sector (or analyzer) selects and focuses ions of the same kinetic energy. The electric sector does not separate ions according to mass or charge, and therefore is always used in conjunction with a magnetic analyzer, often in a double-focusing mass spectrometer. The electric sector is also sometimes called an electrostatic sector or electrostatic analyzer.
The application of electrochemical cells and electrochemical techniques for
chemical analysis. The analyte is dissolved in the electrolyte of the cell, and
one can perform either "qualitative" analysis (determination of the type of
constituents present) or "quantitative" analysis (determination of the amount of
a given constituent).
Electron attachment is a process in which an electron of thermal energy is added to an atom or molecule (M) to form a stable ion (M- ). The molecule must have a positive electron affinity (for example, be electrophoric). Thermal electrons are required so as not to cause dissociation of the molecular ion.
A device that responds to decreases in an electrical current as the analyte passes through a plasma. In ECD, a detector ionizes solutes by collision with metastable carrier-gas molecules produced by ß-emission from a radioactive source such as 63Ni. The electron-capture detector is one of the most sensitive detectors, and it responds strongly to halogenated solutes and others with high electroncapture cross-sections.
Electron impact ionization or as currently preferred electron ionization
represents the classical method of ion generation in mass spectrometry. The analyte is
introduced into the evacuated ion source (<10-6 mbar) and subsequently ionized by collisions with energetic electrons (routine 70 eV) generated by thermal emission from a
An electron multiplier is a detection device inside the vacuum of the mass spectrometer that converts the arrivals of ions at its front dynodes into a detectable, amplified electron current at the back lead of the device. The overall gain (signal out/signal in) can be as high as 104–108. Positive ions exiting from the mass analyzer impact the first dynode surface, and the impact causes the release of several electrons, which are then accelerated through a potential to the next electrode. There, each electron impact causes the release of several secondary electrons, which are accelerated into the next dynode for a repetition of the impact–release process. A cascade of electrons is produced, generating a current that is further amplified and then sampled by an analog-to-digital converter to be recorded by the data system.
A form of molecular spectroscopy concerned with microwave-induced transitions between magnetic energy levels of electrons having a net spin and orbital angular momentum. The spectrum is normally obtained by magnetic field scanning. Also known as electron spin resonance (ESR) spectroscopy or electron magnetic resonance (EMR) spectroscopy.
The frequency (ν) of the oscillating magnetic field to induce transitions between the magnetic energy levels of electrons is measured in gigahertz (GHz) or megahertz (MHz). The following band designations are used: L (1.1 GHz), S (3.0 GHz) , X (9.5 GHz), K (22.0 GHz) and Q (35.0 GHz). The static magnetic field at which the EPR spectrometer operates is measured by the magnetic flux density (B) and its recommended unit is the tesla (T). In the absence of nuclear hyperfine interactions, B and are related by : h ν = g µBB where h is the Planck constant, µB is the Bohr magneton, and the dimensionless scalar g is called the g-factor. When the paramagnetic species exhibits an anisotropy, the spatial dependency of the g-factor is represented by a 3x3 matrix. The interaction energy between the electron spin and a magnetic nucleus is characterized by the hyperfine coupling constant A. When the paramagnetic species has anisotropy, the hyperfine coupling is expressed by a 3x3 matrix called a hyperfine coupling matrix. Hyperfine interaction usually results in splitting of lines in an EPR spectrum. The nuclear species giving rise to the hyperfine interaction should be explicitly stated, e.g."the hyperfine splitting due to 65Cu". When additional hyperfine splittings due to other nuclearspecies are resolved ("superhyperfine"), the nomenclature should include the designation of the nucleus, and the isotopic number
EPMA (EMPA) is an analytical technique used to determine the chemical nature of extremely small samples by forming the X-ray spectrum of the sample through excitation by a finely focused electron beam.
Electrophoresis is based on the migration of charged molecules in solution in response to an electric field. Their rate of migration depends on the strength of the field; on the nett charge, size and shape of the molecules and also on the ionic strength, viscosity and temperature of the medium in which the molecules are moving. As an analytical tool, electrophoresis is simple, rapid and highly sensitive. It is used analytically to study the properties of a single charged species, and as a separation technique.
A mass spectrometric technique for liquid samples that involves preparing electrically charged droplets from analyte molecules dissolved in a solvent. The electrically charged droplets enter a vacuum chamber where the solvent is evaporated. Evaporation of solvent reduces the droplet size, thereby increasing the coulombic repulsion within the droplet. As the charged droplets get smaller, the excess charge within them causes them to disintegrate and release analyte molecules. The volatilized analyte molecules are then analyzed by mass spectrometry.
An electrothermal atomizer is a device which is heated, to the temperature required for analyte atomization, by the passage of electrical current through its body. This technique has largely been developed for use in atomic absorption spectrometry for which the terms electrothermal atomic absorption spectrometry, electrothermal AAS and the abbreviation ETAAS are defined. It has also been applied in atomic emission and atomic fluorescence spectrometry, with appropriate analogous terms, such as electrothermal atomic emission spectrometry (ETAES) and electrothermal atomic fluorescence spectrometry (ETAFS), being defined.
An electrothermal vaporizer (ETV) is a device which is heated, to the temperature required for analyte vaporization, by the passage of electrical current through its body. The ETV is used as a sample introduction device for liquid and solid samples into a spectroscopic excitation or ionization source such as a flame or plasma discharge. The combined technique allows for the independent control of the vaporization parameters and the atomization/ionization parameters. Combined techniques often used are: ETV-ICP-AES, ETV-ICP-MS, ETV-MIP-AES
In elemental mass spectrometry, a technique used mostly for inorganic
materials, the elemental composition of a sample is determined
than the structural identities of its chemical constituents.
mass spectrometry provides quantitative information about the
of those elements. The ion source used in elemental MS is
an atmospheric-pressure discharge such as the inductively
(ICP) or a moderate-power device such as the glow-discharge
In either case, the decomposition of the sample into its
atoms and ionization of those atoms occurs in a specially
The resulting atomic-ion beam is then separated or sorted by a
spectrometer and the signal as a function of m/z used to
Hg. Mercury in its elemental (pure) form,
that is, as a metal; hence the synonym metallic mercury. A shiny, silver-gray
metal that is a liquid at room temperature. Elemental mercury has many uses and is for instance found in thermometers,
barometers, dental amalgams, batteries, fluorescent lights and some electrical
switches. It is rarely found in nature.
Continuous or repeated measurement of agents in the environment to evaluate environmetal exposure and possible damage by comparison with appropriate reference values based on knowlege of the probable relationship between ambient exposure and resultant adverse effects.
The digestion of a peptide, protein, or mixtures of peptides and/or proteins with an enzyme such as trypsin, chymotrypsin, pepsin, endoproteinase Glu-C, endoproteinase Lys-C and endoproteinase Asp-N. This is a key step in many proteomics analyses.
A macromolecule that functions as a biocatalyst by increasing the
reaction rate, frequently containing or requiring one or more metal
ions. In general, an enzyme catalyzes only one reaction type (reaction
specificity) and operates on only a narrow range of substrates
(substrate specificity). Substrate molecules are attacked at the same
site (regiospecificity) and only one or preferentially one of the
enantiomers of chiral substrate or of racemic mixtures is attacked
Abbreviation for "Extractable Organohalogens".
The fraction of AOX which is extractable by a non-polar organic
solvent. This fraction contains the relatively lipophilic
(fat-soluble) organic compounds. EOX gives a better indication of
the amount of organic halogens susceptible to lipophilic
absorption. It often represents about one tenth of the AOX
Electrothermal atomic absorption spectrometry : A type of atomic absorption spectrometry where the sample is atomised using a probe which is rapidly heated by passing a current through it. The probe often is either a graphite tube or a tungsten coil.
C2H5Hg+. Ethylmercury is a cation that forms organic mercury
compounds such as ethylmercury chloride and ethylmercury urea. Thimerosal is
also an ethylmercury salt: sodium ethylmercuric thiosalicylate. The term
'ethylmercury' is sometimes used as a generic term to describe ethylmercury
The Scientific Committee on Toxicity, Ecotoxicity and the Environment (CSTEE)
was created by the European Commission to address "scientific and
technical questions relating to examination of the toxicity and
ecotoxicity of chemical, biochemical and biological compounds whose use
may have harmful consequences for human health and the environment."
(Source: CSTEE website)
"Following a series of food scares in the 1990s (eg BSE, dioxins…)
which undermined consumer confidence in the safety of the food chain,
the European Union concluded that it needed to establish a new
scientific body charged with providing independent and objective advice
on food safety issues associated with the food chain. Its primary
objective as set out in the White Paper on Food Safety would be to:
“…contribute to a high level of consumer health protection in the area
of food safety, through which consumer confidence can be restored and
maintained.” The result was the European Food Safety Authority (EFSA).
up provisionally in Brussels in 2002, EFSA provides independent
scientific advice on all matters linked to food and feed safety -
including animal health and welfare and plant protection - and provides
scientific advice on nutrition in relation to Community legislation.
The Authority communicates to the public in an open and transparent way
on all matters within its remit. EFSA’s risk assessments provide risk
managers (consisting of EU institutions with political accountability,
i.e. European Commission, European Parliament and Council) with a sound
scientific basis for defining policy driven legislative or regulatory
measures required to ensure a high level of consumer protection with
regards to food safety." (Source: EFSA website)
The process of finding out how people come into contact with a hazardous
substance, how often and for how long they are in contact with the substance,
and how much of the substance they are in contact with.
The route a substance takes from its source (where it began) to its end
point (where it ends), and how people can come into contact with (or get
exposed to) it. An exposure pathway has five parts: a source of contamination
(such as an abandoned business); an
media and transport mechanism (such as movement through groundwater);
a point of exposure (such as a private
well); a route of exposure (eating, drinking,
breathing, or touching), and a receptor
population (people potentially or actually exposed). When all five
parts are present, the exposure pathway is termed a completed exposure
pathway. Source: ATSDR Glossary of Terms
A method of estimating the amount of people's past exposure to hazardous
substances. Computer and approximation methods are used when past information
is limited, not available, or missing. Source: ATSDR Glossary of Terms
Part of an X-ray absorption spectrum that is used to identify the coordination of atoms, estimate bond lengths, and determine the adsorption complexes on the surfaces of adsorbents. EXAFS spectra may provide useful information on the speciation (valence state), surface complexes, and the coordination of the target atom (compare with X-ray absorption spectroscopy (XAS), X-ray absorption near edge structure (XANES) spectra, and X-ray absorption fine structure spectroscopy (XAFS)).
"The EXTension TOXicology NETwork (EXTOXNET) is an effort of
University of California, Davis, Oregon State University, Michigan
State University, Cornell University, and the University of Idaho.
of the goals of EXTOXNET are to stimulate dialog on toxicology issues,
develop and make available information relevant to extension
toxicology, and facilitate the exchange of toxicology-related
information in electronic form, accessible to all with access to the
The EXTOXNET InfoBase is accessible via the World Wide Web (WWW)."
(Source: EXTOXNET website)
An extracted ion profile is the plot of signal intensity observed at one or more selected m/z
values in a series of mass spectra that are recorded as a function of
time. Examples are extracted ion chromatogram, extracted ion
electropherogram, flow injection analysis or any other time-dependent
The removal of a soluble material from a solid mixture by means of a solvent or the removal of one or more components from a liquid mixture by use of a solvent with which the liquid is immiscible or nearly so.