base peak


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base peak

The ion in a mass spectrum with the highest measured abundance.
The relative abundance of the base peak ion is assigned a value of 100, and the abundances of all other ions plotted in that mass spectrum are normalised to that value. The y-axis in a mass spectrum is therefore given in terms of relative abundance.
References in periodicals archive ?
The observed base peak at M/Z 163 may be explained by the cleavage of the bond alpha to the carbonyl moiety, leading to the loss of a methoxy group.
For the DMDCS derivative of 9-hydroxyphenanthrene, the molecular ion is at the m/z value (mass-to-charge ratio) of 286, which is the base peak of the mass spectrum.
The base peak may exhibit minor tailing for an active or contaminated column.
We were able to determine that the metabolite had a base peak of 270 m/z while metolachlor had a base peak of 284 m/z, suggesting O-demethylation of metolachlor leading to the formation of 2-chloro-N-(2-ethyl-6-methylphenyl)-N-(2-hydroxy-1-methylethyl)-acetamide.
This is especially necessary following a summer in which GPU Energy set a new all time peak demand and PJM exceeded its 1999 base peak load estimate by almost 4,000 megawatts.
The PD values of the linear samples and the base peaks of the coupled samples are quite low as expected for batch-produced anionic PBd.