Neutral loss definition

Nitroarenes are recognized from their characteristic neutral losses due to the NO2 substituent. Normally, all theoretically possible fragment ions, the plausible [M-N02] and [M-O] ions as well as the unexpected [M-NO] ion, are observed. It is worth noting that molecular ions are 1,2-distonic by definition, because nitroarene molecules are best represented as zwitterion (Chap. 6.3). The molecular ion may either dissociate directly by loss of an oxygen atom or a NO2 molecule or it may rearrange prior to loss of NO. For the latter process, two reaction pathways have been uncovered, one of them involving intermediate formation of a nitrite, and the other proceeding via a three-membered cyclic intermediate. [208]... 

In triple quadmpole instruments Qi and Q3 are operated independently as MSI and MS2, respectively, making MS/MS straightforward. The experimental setups for product ion, precursor ion, and neutral loss scanning are summarized in Table 9.3 and depicted in Fig. 9.18. Definitely, this instrument class offers the most easily understandable tandem MS modes of operation. 

At any interface between two different phases there will be a redistribution of charge in each phase at the interface with a consequent loss of its electroneutrality, although the interface as a whole remains electrically neutral. (Bockris considers an interface to be sharp and definite to within an atomic layer, whereas an interphase is less sharply defined and may extend from at least two molecular diameters to tens of thousands of nanometres the interphase may be regarded as the region between the two phases in which the properties have not yet reached those of the bulk of either phase .) In the simplest case the interface between a metal and a solution could be visualised as a line of excess electrons at the surface of the metal and an equal number of positive charges in the solution that are in contact with the metal (Fig. 20.2). Thus although each phase has an excess charge the interface as a whole is electrically neutral. 

Lastly, the positive charge is neutralized via loss of a proton, giving the alkene lanosterol. There is no obvious energy advantage in such tertiary-to-tertiary cation changes, but it must be appreciated that this is an enzyme-catalysed reaction, and the enzyme plays a crucial role in the reactions that occur. These hydride and methyl migrations definitely do occur, as demonstrated by isotopic labelling studies. 

Now he had to act quickly. He was going to strip an electron from an atom of this neutral oil droplet. Radium could do this. He held a small tube of radium so that its rays would strike the oil drop. Something happened. The neutral droplet slowed down in its fall. When this occurred, Millikan knew, the droplet was no longer neutral it had lost some of its electrons and become positively charged/ By observing the change in speed with which it travelled he could determine how many electrons it had lost. He noticed that the droplet always travelled at definite rates of speed. There was a certain minimum speed. The speed would be suddenly doubled, then tripled. It was easy to see, wrote Millikan, that the slowest speed was the result of the loss of one electron. This proved conclusively that the smallest invisible load which I was able to remove from the droplet was actually one electron and that all electrons consist of exactly the same quantity of negative electricity. ... 

Oxidation is a chemical change in which electrons are lost by an atom or group of atoms, and reduction is a chemical change in which electrons are gained by an atom or group of atoms. These definitions can be applied most simply in the case of elementary substances and their ions. A transformation that converts a neutral atom to a positive ion must be accompanied by the loss of electrons and must, therefore, be an oxidation. Consider the following example ... 

Pitting arises when localized/aggressive environments break down the nominally passive and corrosion-resistant film. Pits may form at scratches, mechanical defects, second phase particles, or stochastic local discontinuities in the oxide film. Since by definition pitting refers to local loss passivity, pitting only occurs in the near-neutral pH range for Al. 

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