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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)



A nanoparticle is a microscopic particle whose size is measured in nanometres. Nanoparticles are thus larger than angstroms (Ĺ), but smaller than micrometres. At the small end of the size range, nanoparticles are often referred to as clusters (cluster (physics)).
Metal, dielectric, and semiconductor nanoparticles have been formed, as well as hybrid structures (e.g., core-shell nanoparticles). Nanospheres, nanorods, and nanocups are just a few of the shapes that have been grown. Semiconductor quantum dots and nanocrystals are types of nanoparticles.
Nanoparticle characterization is necessary to establish understanding and control of nanoparticle synthesis and applications. Characterization is done by using a variety of different techniques, mainly drawn from materials science. Common techniques are electron microscopy, Atomic force microscopy, x-ray photoelectron spectroscopy, fourier transform infra red spectroscopy (FTIR).
Nanoparticle research is currently an area of intense scientific research, due to a wide variety of potential applications in biomedical, optical, and electronic fields.
In biomedical applications nanoparticles are used as drug carriers or imaging agents. For this purpose the nanoparticle may have a hollow structure providing a central reservoir that can be filled with anticancer drugs, detection agents, or chemicals, known as reporters, that can signal if a drug is having a therapeutic effect. The surface of a nanoparticle can also be adorned with various targeting agents, such as antibodies, drugs, imaging agents, and reporters. Most nanoparticles are constructed to be small enough to pass through blood capillaries and enter cells.

The term nanospray describes a design for a miniaturized electrospray ionization source using a pulled and coated glass capillary as the spray tip. This design achieves a flow rate of 20–50 nL/min, much lower than the usual electrospray ionization source.

The term nanotechnology applies to materials, structures and technologies with one thing in common: the creation or presence of at least one spatial dimension smaller than a few hundred nanometers. This includes the production of nanoparticles and the creation of nanostructures, which in turn make it possible to produce products with new or improved properties. Examples include starting materials for textiles that absorb UV radiation, water-repellant surface coatings for the textile and automotive industries and coatings that are more scratch resistant.

natural isotopic abundance
Of a specified isotope of an element, the isotopic abundance in the element as found in nature

Part of the sample introduction system of analytical systems used for aerosol generation from liquid samples.

neutron activation analysis (NAA)
A nuclear process whereby the elements in a material can be qualitatively and quantitatively determined.

- A malleable, silvery metal with excellent resistance to corrosion. Used in the production of alloys, electroplating, catalysts, welding rods and coinage and can be found in electronic equipment, construction materials, aerospace equipment and consumer goods such as alkaline batteries, paints and ceramics.  Hazard: Ingestion of nickel may cause nausea, vomiting and diarrhea. Hypersensitivity to nickel is common and can cause allergic contact dermatitis, pulmonary  asthma, and conjunctivitis.

nickel carbonyl
Nickel carbonyl, or tetracarbonylnickel is a  covalent compound of nickel, which is, unusually for a metal compound, a colorless liquid at room temperature. Its formula is Ni(CO)4. It is highly toxic and may be fatal if ingested or absorbed through the skin, earning it the nickname "liquid death". Nickel carbonyl is extremely volatile. It evaporates at room temperature. The vapours can autoignite.  The volatile metalloid compound is used to refine nickel by the Mond process; also used to deposit nickel films and as a catalyst to produce organic chemicals. Nickel carbonyl has been identified in a variety of anthropogenic gases, e.g. landfill gas and sewage sludge digester gas and emissions of automobiles.

Nier-Johnson geometry
The Nier-Johnson geometry is an instrumental design used in double-focusing mass spectrometers when the electric field and magnetic field are arranged at deflection angles of π/2 and π/3 radians respectively.

Arsenic compound (4-nitrophenylarsonic acid, 4-NPAA) used as animal feed additive for the prevention of blackhead (Histomoniasis) in turkeys.

NMR spectroscopy
Nuclear magnetic resonance spectroscopy, most commonly known as NMR spectroscopy, is the name given to a technique that exploits the magnetic properties of certain nuclei. The most important applications for the organic chemist are proton NMR and carbon-13 NMR spectroscopy. In principle, NMR is applicable to any nucleus possessing spin. Many types of information can be obtained from an NMR spectrum. Much like using infrared spectroscopy  (IR) to identify functional groups, analysis of a NMR spectrum provides information on the number and type of chemical entities in a molecule. However, NMR provides much more information than IR.

no-observed-adverse-effect level (NOAEL)
Greatest concentration or amount of a substance, found by experiment or observation, which causes no detectable adverse alteration of morphology, functional capacity, growth, development, or life span of the target organism under defined conditions of exposure.
Note:       When derived from a life-cycle or partial life-cycle test, it is numerically the same as the lower limit of the maximum acceptable toxicant concentration.

no-observed-effect level (NOEL)
Greatest concentration or amount of a substance, found by experiment or observation, that causes no statistically significant alterations of morphology, functional capacity, growth, development, or life span of  target  organisms  distinguishable  from  those  observed  in  normal  (control)  organisms  of  the  same species and strain under the same defined conditions of exposure.

NOM - natural organic matter
Natural organic matter (NOM) is a term collectively used to describe the complex matrix of organic material present in natural waters. It encludes the dissolved part, DOM, dissolved organic matter. It is a relatively undefined material consisting of numerous organic compounds but is known to contain many functional groups such as carboxyl, phenoxy and hydroxyl radicals that can participate in the formation of metallic complexes during coagulation of natural waters using either Al based or Fe based metal coagulant salts. NOM is quantified by measuring dissolved organic carbon (DOC). Fulvic and humic acids represent a major fraction of DOC.

nominal ion mass
The nominal ion mass is the mass of an ion for a given empirical formula calculated using the integer mass of the most  abundant isotope of each element (for example, C is 12 Da, H  is 1 Da, and O is 16 Da).

normalisation of a mass spectrum
Is the process of adjusting the isotopic abundances of a chemical element for isotopic fractionation.

normalising isotopes
Are the pair of isotopes whose abundance ratio is used to correct or adjust isotopic abundances for bias due to isotopic fractionation. The pair is chosen to suit the situation.

nuclear microprobe
Particle-Induced X-ray Emission Analysis (PIXE) technique, in which the particle beam is collimated and/or focused down to dimensions in the range of 1-50 µm (also called micro-PIXE).

Ability of an electron-rich chemical species to donate two electrons forming a covalent bond with a positive nuclear charge of an electron-poor species, known as an electrophile.

Nucleopore filter
A filter with micron and submicron sized pores. The pores are of controlled and uniform size, produced by chemically etching radiation damage tracks of heavy ions with which the filters are bombarded as part of the production process.

A general term applied to any atom with data on the number of protons and neutrons in its nucleus

number of theoretical plates
- an indicator of separation efficiency or the ability to give narrow peaks. The higher the number of theoretical plates, the better is the separation efficiency.

Nutrigenomics is the application of the sciences of genomics, transcriptomics, proteomics and metabolomics to human nutrition, especially the relationship between nutrition and health. Nutrition and health research is focused on the prevention of disease by optimizing and maintaining cellular, tissue, organ and whole-body homeostasis . This requires understanding, and ultimately regulating, a multitude of nutrient-related interactions at the gene, protein and metabolic levels.

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