| spectrometry, gamma | Determination of the energy distribution of gamma rays emitted by nuclei. (12 Dec 1998) |
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| spectrometry, mass, fast atom bombardment | A mass spectrometric technique that is used for the analysis of a wide range of biomolecules, such as glycoalkaloids, glycoproteins, polysaccharides, and peptides. Positive and negative fast atom bombardment spectra are recorded on a mass spectrometer fitted with an atom gun with xenon as the customary beam. The mass spectra obtained contain molecular weight recognition as well as sequence information. (12 Dec 1998) |
| spectrometry, mass, matrix-assisted laser desorption-ionization | A mass spectrometric technique that is used for the analysis of large biomolecules. Analyte molecules are embedded in an excess matrix of small organic molecules that show a high resonant absorption at the laser wavelength used. The matrix absorbs the laser energy, thus inducing a soft disintegration of the sample-matrix mixture into free (gas phase) matrix and analyte molecules and molecular ions. In general, only molecular ions of the analyte molecules are produced, and almost no fragmentation occurs. This makes the method well suited for molecular weight determinations and mixture analysis. (12 Dec 1998) |
| spectrometry, mass, secondary ion | A mass-spectrometric technique that is used for microscopic chemical analysis. A beam of primary ions with an energy of 5-20 kiloelectronvolts (kev) bombards a small spot on the surface of the sample under ultra-high vacuum conditions. Positive and negative secondary ions sputtered from the surface are analyzed in a mass spectrometer in regards to their mass-to-charge ratio. (12 Dec 1998) |
| spectrometry, X-ray emission | Identification and measurement of concentration of elements based on the fact that X-rays emitted by an excited element have a wavelength characteristic of that element and an intensity related to its concentration. It includes fluorescence, or secondary-emission, X-ray spectrometry, in which the specimen is irradiated by X-rays. Primary-emission x-ray spectrometry, in which the specimen is bombarded by electrons, is a specific type of X-ray emission spectrometry known as electron probe microanalysis. (12 Dec 1998) |
| spectrophobia | <psychology> Morbid fear of mirrors or of one's mirrored image. Origin: spectro-+ G. Phobos, fear (05 Mar 2000) |
| spectrophotofluorimetry | Measurement of the intensity and quality of fluorescence by means of a spectrophotometer. (05 Mar 2000) |
| spectrophotometer | A machine used to measure how much light of a given wavelength is absorbed by a liquid sample, or to measure how intense (bright) the spectral lines and bands produced by the sample are, relative to each other. (09 Oct 1997) |
| spectrophotometry | Quantitative measurements of concentrations of reagents made by measuring the absorption of visible, ultraviolet or infrared light. (18 Nov 1997) |
| spectrophotometry, atomic absorption | A highly sensitive technique used to analyze various elements, especially metals, including aluminum, arsenic, beryllium, calcium, copper, iron, lead, and lithium, which are present in trace amounts. The atoms are excited above a ground state by flame vaporization, and the radiation emitted as the molecules return to a ground state is measured in unexcited non-ionised molecules. (12 Dec 1998) |
| spectrophotometry, infrared | Spectrophotometry in the infrared region, usually for the purpose of chemical analysis through measurement of absorption spectra associated with rotational and vibrational energy levels of molecules. (12 Dec 1998) |
| spectrophotometry, ultraviolet | Determination of the spectra of ultraviolet absorption by specific molecules in gases or liquids, for example cl2, so2, no2, cs2, ozone, mercury vapor, and various unsaturated compounds. (12 Dec 1998) |
| spectropolarimeter | An instrument for measuring the rotation of the plane of polarised light of specific wavelength upon passage through a solution or translucent solid. Origin: spectro-+ polarimeter (05 Mar 2000) |
| spectroscope | <instrument, physics> An optical instrument for forming and examining spectra (as that of solar light, or those produced by flames in which different substances are volatilized), so as to determine, from the position of the spectral lines, the composition of the substance. Origin: Spectrum + -scope. Source: Websters Dictionary (01 Mar 1998) |
| spectroscopic | Relating to or performed by means of a spectroscope. (05 Mar 2000) |