Specifying ion m/z

M/Z Controlled Vocabulary Terms

Term	Intended Use
MS:1000744|selected ion m/z	The selected precursor ion as reported by the instrument for isolation. Should be used for a Spectrum
MS:|experimentally determined monoisotopic m/z	The monoisotopic peak of the selected ion as determined by the implementation. Usually used for a Spectrum, but for chimeric or ambiguous spectra may also be used in an Interpretation or InterpretationMember
MS:1003053|theoretical monoisotopic m/z	The theoretical m/z for an ion calculated by the implementation. Should be used for an Analyte

Selected Ion M/Z

The selected ion m/z term is intended to be used in mzSpecLib in the same manner as in mzML. It reflects the assumption that this value is not refined by some other method that the implementation used, and carries with it the same uncertainty. Because it is not directly related to an Analyte’s identity, this attribute belongs to the Spectrum alone.

Experimentally Determined Monoisotopic M/Z

The experimentally determined monoisotopic m/z term was created for mzSpecLib to indicate that this m/z value was refined in some way by the implementation. This implies that the value is expected to be correct in-so-far as the implementation can tell.

Because the determination might be done with information about an Analyte, this attribute could appear under either the Spectrum or the Interpretation or InterpretationMember sections.