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Topic: Mass spectrograph

	mass spectrograph - HighBeam Encyclopedia
		mass spectrograph device used to separate electrically charged particles according to their masses; a form of the instrument known as a mass spectrometer is often used to measure the masses of isotopes of elements.
		In the mass spectrograph the particles, in the form of ions, pass through deflecting fields (produced by carefully designed magnetic pole pieces and electrodes) and are detected by photographic plates.
		The mass spectrograph is widely used in chemical analysis and in the detection of impurities.
	www.encyclopedia.com /doc/1E1-massspec.html (359 words)

	U.S. Patent: 5747815 - Micro-miniature ionizer for gas sensor applications and method of making micro-miniature ionizer ...
		The mass spectrograph gas ionizer of claim 2, wherein the alkali halide salt layer is cesium chloride.
		The mass spectrograph gas ionizer of claim 5, wherein the alkali halide salt layer is cesium chloride.
		The mass spectrograph ionization chamber 49 may be modeled using radioisotopes as a rectangular tube, coated on four walls with the radioactive material, and having gas flow through this tube.
	www.everypatent.com /comp/pat5747815.html (6607 words)

	Highbeam Encyclopedia - Search Results for mass
		center of mass the point at which all the mass of a body may be considered to be concentrated in analyzing its motion.
		The center of mass of a sphere of uniform density coincides with the center of the sphere.
		atomic mass unit or amu, in chemistry and physics, unit defined as exactly 1/12 the mass of an atom of carbon-12, the isotope of carbon with six protons and six neutrons in its nucleus.
	www.encyclopedia.com /searchpool.asp?target=mass (658 words)

	Mass Spectrometry
		Mass spectrometry uses mass spectrometers and mass spectrographs to identify chemical substances by analyzing the ions in electromagnetic fields according to mass-to-charge ratios.
		In other words, it measures their mass and their charge and determines what substance and isotope they are based on those two variable characteristics and some constants.
		Mass spectrometry has been crucial since the dawn of modern chemistry and physical chemistry, and continues to be important today in dozens of applied science fields.
	www.iscid.org /encyclopedia/Mass_Spectrometry (185 words)

	Mass spectrometry Summary
		Mass spectrometry is a very sensitive analytical technique that permits the detection of trace amounts of a substance, such as the amount of ozone in a sample of air.
		Mass spectrometry is an analytical technique used to measure the mass-to-charge ratio of ions.
		A mass spectrometer is able to measure the ratio of these radio-isotopes to that of the stable isotope, this ratio is then used to find the absolute amount of radio-isotope in the object.
	www.bookrags.com /Mass_spectrometry (6239 words)

	From TNT to BTX to DNA
		Called a mass spectrograph, the device sensitively separated isotopes of the same element based on differences in the deflection of ions in a magnetic field; because the ions of each isotope differ in mass and charge, they can be magnetically separated, collected, and counted in a specific part of the instrument.
		In tandem mass spectrometry, the ions produced by the glow discharge source, often referred to as parent ions, are mass-selected and caused to dissociate prior to a second stage of mass analysis.
		Mass spectrometry-based explosives detection technology is being considered both for security applications, such as airport security, and for detection of land mines and buried munitions.
	www.ornl.gov /info/ornlreview/measure/analy/fromtnt/tnt.htm (4487 words)

	Mass spectrum - Wikipedia, the free encyclopedia
		Hence, the mass spectrum of a sample is a pattern representing the distribution of components (atoms or molecules) by mass (more correctly: mass-to-charge ratio) in a sample.
		The x-axis of a mass spectrum represents a relationship between the mass of a given ion and the number of elemetary charges that it carries.
		Francis William Aston won the nobel prize in Chemistry in 1922 [3] "For his discovery, by means of his mass spectrograph, of isotopes, in a large number of non-radioactive elements, and for his enunciation of the whole-number rule." In which he stated that all atoms (including isotopes) follow a whole-number rule [4].
	en.wikipedia.org /wiki/Mass_spectrum (1310 words)

	Aston's experiment
		The spectrograph, made in 1919 and working until 1925, let evaluate the atomic mass of isotopes with the accuracy to 1 percent.
		Almost a hundred years before William Prout brought forward a hypothesis that all atoms consisted of basal elements which mass is equal to hydrogen mass.
		Now it was proved that there is no chlorine with mass equal 35,5 but two isotopes of chlorine with masses equal 35 and 37 in the proportions making the mean mass equal 35,46.
	library.thinkquest.org /19662/low/eng/exp-aston.html (1063 words)

	Nobel Prize in Chemistry 1922 - Presentation Speech
		Thanks to the substantially increased sharpness and fineness that the analysis of the anode rays has obtained by means of the mass spectrograph, Aston has succeeded in proving that a large number of fundamental elements which have hitherto been regarded as simple are in reality complexes of two or more isotopes.
		It is indeed still more remarkable that all the masses so far measured of the recently enumerated elements and several others, and also the masses of their isotopes, can be expressed by means of whole numbers in relation to oxygen-16.
		It is precisely the atomic weight of hydrogen which has in the mass spectrograph shown itself to be encumbered with a fraction; not large, it is true-it amounts to only o.oo8-but still sufficiently large not to be explained away as an error of observation.
	www.geocities.com /ray_333kod/aston-bio.html (1208 words)

	atomic mass unit
		Since 1961, by definition the unified atomic mass unit is equal to one-twelfth of the mass of the nucleus of a carbon-12 atom.
		The mass of the unified atomic mass unit is determined experimentally.
		physicists were using an atomic mass unit defined as equal to one-sixteenth of the mass of the oxygen-16 atom (the isotope of oxygen containing a total of 16 protons and neutrons).
	www.sizes.com /units/atomic_mass_unit.htm (1060 words)

	Mass spectrometry - Wikipedia, the free encyclopedia
		Mass analyzers separate the ions according to their mass-to-charge ratio.
		The cylindrical ion trap mass spectrometer is a derivative of the quadrupole ion trap mass spectrometer.
		Ion cyclotron resonance is an older mass analysis technique similar to FTMS except that ions are detected with a traditional detector.
	en.wikipedia.org /wiki/Mass_spectrometry (5079 words)

	Case 83 --Clinical Chemistry Case
		Modern mass spectrographs typically use only one detector, and instead use a complex analyzer (the quadrupole analyzer) to change the electric field experienced by the beam of molecular fragments so that only fragments with a particular mass/charge ratio will hit the detector at a particular time.
		The placing of a mass spectrograph in tandem with a gas chromatograph instrument tends to produce an enormous amount of data, since a mass spectrograph is obtained for each different retention time.
		Historically, mass spectral data were identified by hand by comparison to tabulated values; now this task is usually automatically provided by the computer which uses large libraries of on-board spectral data.
	path.upmc.edu /cases/case83/gas.html (981 words)

	Francis William Aston Summary
		The mass spectrograph he built used electrical and magnetic fields to separate a beam of positive rays into distinct lines, in much the same way that a spectroscope separates white light into colored bands.
		When neon was analyzed with the mass spectrograph, it produced two clear and distinct lines, one representing an atomic weight of 20 and one a weight of 22.
		Aston received the Nobel Prize in chemistry in 1922 for the invention of the mass spectrograph and for the knowledge of isotopes it led to.
	www.bookrags.com /Francis_William_Aston (2390 words)

	Soviet Craft - Vega
		The UV spectrometer, mass spectrograph, and pressure- and temperature-measuring instruments were developed in cooperation between French and Soviet investigators.
		The amplitude was proportional to the mass of the dust particle.
		The magnitude of the signal was a known function of the mass and the velocity of the impacting particle.
	filer.case.edu /~sjr16/advanced/20th_soviet_vega.html (3156 words)

	AllRefer.com - atomic mass (Chemistry) - Encyclopedia
		Each proton or neutron weighs about 1 amu, and thus the atomic mass is always very close to the mass number (total number of protons and neutrons in the nucleus).
		Atoms of an isotope of an element all have the same atomic mass.
		Atomic masses are usually determined by mass spectrography (see mass spectrograph).
	reference.allrefer.com /encyclopedia/A/atomMas.html (204 words)

	High-throughput method and apparatus for identifying, quantitating and determining the purity of chemical compounds in ... (Site not responding. Last check: 2007-10-11)
		The chromatographic and mass spectroscopic data generated by the mass spectrograph are used to purify several compounds of interest from the mixture through a system including a second HPLC column and a UV absorbance detector.
		For embodiments in which a mass spectrograph is used as the compound-identifying device 210, a peak is identified as corresponding to, and confirming the presence of, the compound interest when its mass spectrograph-determined molecular weight matches the (known) molecular weight of the compound of interest.
		The mass spectrograph 510 is operable to calculate molecular weight, which is used to confirm the identity of a compound of interest.
	www.freepatentsonline.com /5938932.html (5266 words)

	Scripps Center for Mass Spectrometry - MS History
		This method was used in the early mass analysis measurements of Wien (1898), Thomson (1912), and Aston (1919).
		Smyth (1922) described the first mass spectrometer for electron ionization of gases and vapors, continuing to use Dempster's method of axial electrons with 180 degree analysis.
		Hipple, at Westinghouse in 1942 and Washburn, at CEC in 1943, both reported commercial mass spectrometers which had improved sources over the 1940 Nier design, but complete details of the sources were not immediately published.
	masspec.scripps.edu /MSHistory/perspectives/cjudson.php (883 words)

	Treasures - Astons Mass Spectograph (1919)
		The key advance Aston made to Thomson's apparatus was his arrangement of the electric and magnetic deflecting fields so as to bring rays of uniform charge-to-mass ratio to sharp focus on a photographic plate.
		Aston devised several methods for calibrating his instrument and, in the case of neon, obtained mass lines on his photographic plate at 20 and 22 with the intensities of the lines showing that the two particles occurred in the ratio of 10:1, consistent with an average mass of 20.20, the known atomic weight of neon.
		He had earlier shown that both masses were substances with the same properties as neon and thus neon was the first non-radioactive element proven to be isotopic (atoms with the same chemical properties, but different atomic mass).
	www.sciencemuseum.org.uk /collections/treasures/aston2.asp (221 words)

	The Semiempirical Formula for Atomic Masses
		The difference between the mass number of an isotope and its proton number is called the neutron number because of the strong suspicion that the nuclei are composed of protons and neutrons.
		The modern version of Prout's rule is that the mass M of a nucleus of proton number P and neutron number N is approximately equal to sum of the masses of its constituent protons and neutrons; i.e.,
		This approach explains the difference between the mass of a nucleus and the mass of its constituent protons and neutrons, the binding energy, as being the result of energies associated the interaction of the nucleons.
	www.sjsu.edu /faculty/watkins/semiempirical.htm (1982 words)

	Laboratory for Spectrochemistry
		The combination of an array detector and mass spectrograph facilitates simultaneous and continuous detection across the entire active surface of the array.
		Time-of-flight mass spectrometry (TOFMS) is a nearly ideal approach for use with both LA and GD because it offers high speed capabilities.
		Time-of-flight mass spectrometers typically employ a single reflectron region to compensate for the energy distribution of isomass ions and to improve the overall resolution of the system.
	www.indiana.edu /~gmhlab/research/newideas.htm (816 words)

	Building a better mass trap
		The new mass spectrometer is more accurate and efficient than current models because it can detect all atomic and molecular components at once.
		Mass spectrometers, as much a fixture in scientific labs as microwave ovens are in kitchens, work by charging particles in a sample and determining the weight of the particles.
		The research team compared their new device, which combines a Mattauch-Herzog geometry mass spectrograph and a multi-channel focal plane camera, with the most commonly used mass spectrometers in the world’s scientific labs.
	www.homepages.indiana.edu /102502/text/mass.html (412 words)

	Mass Spectrometry History
		By the end of the 1930's mass spectrometry had become an established technique for the separation of atomic ions by mass.
		In the 1940's the applications of mass spectrometry began to spread away from the previous mostly academic work into more practical fields like nuclear isotope enrichment and the analysis of the components of petroleum.
		In the early 1950's, the fragmentation of small organic molecules was beginning to be understood, but the mass spectrometer was still extremely limited by mass and resolution.
	www.chm.bris.ac.uk /ms/history.html (498 words)

	Base unit definitions: Mole
		Following the discovery of the fundamental laws of chemistry, units called, for example, "gram-atom" and "gram-molecule," were used to specify amounts of chemical elements or compounds.
		But whereas physicists separated isotopes in the mass spectrograph and attributed the value 16 to one of the isotopes of oxygen, chemists attributed that same value to the (slightly variable) mixture of isotopes 16, 17, and 18, which was for them the naturally occurring element oxygen.
		It remained to define the unit of amount of substance by fixing the corresponding mass of carbon 12; by international agreement, this mass has been fixed at 0.012 kg, and the unit of the quantity "amount of substance" was given the name mole (symbol mol).
	physics.nist.gov /cuu/Units/mole.html (359 words)

	Mass Spectrometry Blog
		The Bioanalytical Mass Spectrometry Facility at the University of New South Wales has a peptide collision induced dissociation simulator in which you use a mouse click to break peptide backbone bonds.
		John F J Todd of the University of Kent was awarded the Aston Medal by the British Mass Spectrometry Society.
		Isotope ratio mass spectrometry (IRMS) is figuring prominently in the Floyd Landis, winner of the Tour de France.
	msblog.kermitmurray.com (770 words)

	Nuclear Files: Library: Biographies: Francis William Aston (Site not responding. Last check: 2007-10-11)
		The device was capable of separating isotopes by measuring the minute differences in their masses.
		The invention also prompted him to devise his famous Whole Number Rule which states, "the mass of the oxygen isotope being defined, all the other isotopes have masses that are very nearly whole numbers." The rule became crucial to future developments in nuclear energy technology.
		For his accomplishments in the study of isotopes of non-radioactive elements using the mass spectrograph, Aston was awarded the 1922 Nobel Prize in Chemistry.
	www.nuclearfiles.org /menu/library/biographies/bio_aston-francis.htm (209 words)

	PMSV preliminary documentation
		The PARC Mass Spectrum Viewer (PMSV) is an experimental tool intended to view annotated mass spectrograph data for glycans as processed by tools produced by PARC/CSL.
		The minimum displayed mass is the greater of the least mass value for the data and the "min mass" value.
		The maximum displayed mass is the lesser of the greatest mass value for data and the "max mass" value.
	www2.parc.com /csl/members/goldberg/PMSV.en.html (2830 words)

	Fathom :: The Source for Online Learning
		JJ Thomson, himself a Nobel Laureate, had achieved inconclusive experimental results to this end, but his assistant, Aston, used a quartz microbalance and mass spectrograph to identify two isotopes of the element neon.
		Aston was given the task of improving Thomson's apparatus in which a beam of positively charged particles (positive rays) were deflected by a combination of electric and magnetic fields into sharp visible curves, each representing an individual particle's charge-to-mass ratio.
		Meanwhile his principal experimental tool, the mass spectrograph, has been refined almost beyond recognition, adapted and adopted as an analytical instrument of prime importance in innumerable areas of chemical and biological research and industrial practice.
	www.fathom.com /feature/122356/index.html (848 words)

	Applications of Mass Spectrograph (Site not responding. Last check: 2007-10-11)
		I know that a mass spectrograph has been used to determine the specific charge of positive ions and we may get 1, 2, 3 Parabola’s depending on the number of isotopes the element under study has.
		A mass spectrometer measures charge to mass ratios of ions, so c) should be the correct answer.
		If you use it for a ray, because you don't know how many particles are in the ray, you're only capable of measuring the ratio of charge to mass.
	www.physicsforums.com /showthread.php?t=127133 (296 words)

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