Nominal mass: Difference between revisions
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[http://www.rzuser.uni-heidelberg.de/~bl5/ency/ency.html Little Encyclopedia of MS] | [http://www.rzuser.uni-heidelberg.de/~bl5/ency/ency.html Little Encyclopedia of MS] | ||
:The nominal mass of an ion is calculated by simply adding the integer masses of the lightest isotopes of all elements contributing to the molecule, e.g. to calculate the nominal mass of CH<sub>3</sub>Br you have to use the nominal masses of <sup>12</sup>C, <sup>1</sup>H, and <sup>79</sup>Br to obtain | :The nominal mass of an ion is calculated by simply adding the integer masses of the lightest isotopes of all elements contributing to the molecule, e.g. to calculate the nominal mass of CH<sub>3</sub>Br you have to use the nominal masses of <sup>12</sup>C, <sup>1</sup>H, and <sup>79</sup>Br to obtain M<sub>nomi</sub> = 94 [[amu]] | ||
[http://www1.shimadzu.com/products/lab/mass/a.html Shimadzu Mass Spectrometry Glossary] | [http://www1.shimadzu.com/products/lab/mass/a.html Shimadzu Mass Spectrometry Glossary] | ||
:Same meaning as [[mass number]] (Nearest integer when expressing the mass of an atom in units that define <sup>12</sup>C as 12. The number is approximately the sum of protons and neutrons in the atomic nucleus. In mass analysis the mass number is the sum of the masses of the atoms making up an ion or other particle (<sup>12</sup>C = 12, <sup>1</sup>H = 1, <sup>16</sup>O = 16, <sup>14</sup>N = 14...)) | :Same meaning as [[mass number]] (Nearest integer when expressing the mass of an atom in units that define <sup>12</sup>C as 12. The number is approximately the sum of protons and neutrons in the atomic nucleus. In mass analysis the [[mass number]] is the sum of the masses of the atoms making up an ion or other particle (<sup>12</sup>C = 12, <sup>1</sup>H = 1, <sup>16</sup>O = 16, <sup>14</sup>N = 14...)) | ||
Revision as of 11:57, 5 January 2005
See also Accurate Mass, Average Mass, Atomic Mass Unit, Dalton.
Other Definitiions
- The mass of an ion containing the most abundant isotopes, calculated with nominal atomic weights.??????????????
- The nominal mass of an ion is calculated by simply adding the integer masses of the lightest isotopes of all elements contributing to the molecule, e.g. to calculate the nominal mass of CH3Br you have to use the nominal masses of 12C, 1H, and 79Br to obtain Mnomi = 94 amu
Shimadzu Mass Spectrometry Glossary
- Same meaning as mass number (Nearest integer when expressing the mass of an atom in units that define 12C as 12. The number is approximately the sum of protons and neutrons in the atomic nucleus. In mass analysis the mass number is the sum of the masses of the atoms making up an ion or other particle (12C = 12, 1H = 1, 16O = 16, 14N = 14...))
