Glossary of terms

A device or a combination of devices used to carry out an analytical process. The analytical process is all or part of the analytical procedure that encompasses all steps from the introduction of the sample or the test portion to the production of the result. An analytical instrument may carry out single or multiple analytical procedures. In the latter case it may be selective, i.e. designed to carry out any requested combination of procedures within the set, on each specimen.

Source: Compendium of Chemical Terminology, 2nd ed. (the "Gold Book")

A kind of elemental or isotopic analysis based on the measurement of characteristic radiation from nuclides formed directly or indirectly by activation of the test portion. In general, a specification is added of the type of the incident radiation (e.g. neutron, photon) and its energy (e.g. thermal, fast).

Source: Compendium of Chemical Terminology, 2nd ed. (the "Gold Book")

Mechanization with process control, where process means a sequence of manipulations. One or several functions in an analytical instrument may be automated.

Source: Compendium of Chemical Terminology, 2nd ed. (the "Gold Book")

Scattering of radiation in a generally backward direction. In the assay of radioactivity, it applies to the scattering of radiation into the radiation detector from any material except the sample and the detector. In light scattering, it is said to occur when the scattering angle, θ, is 180°. Conversely, forward scattering occurs when θ is 0°.

Source: Compendium of Chemical Terminology, 2nd ed. (the "Gold Book")

The minimum single result which, with a stated probability, can be distinguished from a suitable blank value. The limit defines the point at which the analysis becomes possible and this may be different from the lower limit of the determinable analytical range.

Source: Compendium of Chemical Terminology, 2nd ed. (the "Gold Book")

A level described by the removal of one electron from the configuration of the neutral ground state. These levels form a spectrum similar to that of a one-electron or hydrogen-like atom but, being single-valency levels, have the energy scale reversed relative to that of single-electron levels. Diagram levels may be divided into valence levels and core levels according to the nature of the electron vacancy. Diagram levels with orbital angular momentum different from zero occur in pairs and form spin doublets.

Source: Compendium of Chemical Terminology, 2nd ed. (the "Gold Book")

For a radioactive substance, the time required for the amount of that substance in a biological system to be reduced to one half of its value by both radioactive decay and biological processes, when the rate of removal is approximately exponential.

Source: Compendium of Chemical Terminology, 2nd ed. (the "Gold Book")

When a beam of electrons strikes a target or specimen there are three ways in which the electrons may lose energy (low energy collisions, X-ray production, and formation of a spectral continuum). The average energy loss per unit distance travelled along the electron path is called electron stopping power.

Source: Compendium of Chemical Terminology, 2nd ed. (the "Gold Book")

An operation (process) as a result of which several microcomponents are isolated in one step. This may be achieved in one of two ways, by transportation either of the matrix or of the microcomponents into a second phase. The first method is widely used in the analysis of relatively simple substances and materials.

Source: Compendium of Chemical Terminology, 2nd ed. (the "Gold Book")

The degree to which a property or a constituent is uniformly distributed throughout a quantity of material. A material may be homogeneous with respect to one analyte or property but heterogeneous with respect to another. The degree of heterogeneity (the opposite of homogeneity) is the determining factor of sampling error.

Source: Compendium of Chemical Terminology, 2nd ed. (the "Gold Book")

A job safety analysis (JSA) is a procedure which helps integrate accepted safety and health principles and practices into a particular task or job operation. In a JSA, each basic step of the job is to identify potential hazards and to recommend the safest way to do the job. Other terms used to describe this procedure are job hazard analysis (JHA) and job hazard breakdown.

Source: Canadian Centre for Occupational Health & Safety

An analytical method in which the rate of a reaction or a related quantity is measured and utilized to determine concentrations.

Source: Compendium of Chemical Terminology, 2nd ed. (the "Gold Book")

The components of the sample other than the analyte.

Source: Compendium of Chemical Terminology, 2nd ed. (the "Gold Book")

The volumetric flowrate of the mobile phase divided by the area of the cross section of the column (cm min−1) i.e. the linear flowrate in a part of the column not containingpacking.

Source: Compendium of Chemical Terminology, 2nd ed. (the "Gold Book")

The active solid, stationary liquid plus solid support, or swollen gel put in the column. The term packing refers to the conditions existing before the chromatographic run is started (i.e. to the material introduced into the column), whereas the stationary phase refers to the conditions during the run.

Source: Compendium of Chemical Terminology, 2nd ed. (the "Gold Book")

Analysis in which substances are identified or classified on the basis of their chemical or physical properties, such as chemical reactivity, solubility, molecular weight,melting point, radiative properties (emission, absorption), mass spectra, nuclear half-life, etc.

Source: Compendium of Chemical Terminology, 2nd ed. (the "Gold Book")

Analyses in which the amount or concentration of an analyte may be determined (estimated) and expressed as a numerical value in appropriate units. Qualitative analysis may take place without quantitative analysis, but quantitative analysis requires the identification (qualification) of the analytes for which numerical estimates are given.

Source: Compendium of Chemical Terminology, 2nd ed. (the "Gold Book")

Any action applied to the sample before the analytical procedure. Such actions include the addition of preservatives, separation procedures, storage at low temperature, protection against light and irradiation, loading, etc.

Source: Compendium of Chemical Terminology, 2nd ed. (the "Gold Book")

Any element having an average concentration of less than about 100 parts per million atoms (ppma).

Source: Compendium of Chemical Terminology, 2nd ed. (the "Gold Book")

Interference caused by a change in the fraction of analyte dissociated, ionized or excited in the gaseous phase. (Note: here 'dissociation' means the formation of free neutral atoms from free molecules in the gaseous phase. The term atomization is here not appropriate because the latter also covers the formation of free atomic ions.) These interferences may be called dissociation, ionization and excitation interference, respectively.

Source: Compendium of Chemical Terminology, 2nd ed. (the "Gold Book")

The error in absorbance which may occur if there is a difference between the (mean) wavelength of the radiation entering the sample cell and the indicated wavelength on the spectrometer scale.

Source: Compendium of Chemical Terminology, 2nd ed. (the "Gold Book")

A region in the chromatographic bed where one or more components of the sample are located. The term band may also be used for it.

Source: Compendium of Chemical Terminology, 2nd ed. (the "Gold Book")