One Molecule, Nearly 24 Million Spectra

GinorMass shows why database size does not necessarily reflect chemical diversity

Category	Detail
Condition	Mass spectral library coverage and characterization
Key Mechanisms	Tandem mass spectra are compared with reference spectra to support molecule identification; repeated spectra of one molecule increase spectral count without increasing chemical diversity.
Target Population	Researchers and laboratories using or evaluating mass spectral libraries
Care Setting	Analytical research and laboratory workflows involving biological, clinical, environmental, or chemical samples

GinorMass contains 23,971,300 experimentally acquired tandem mass spectra, all representing authenticated arginine.
The study demonstrates that total spectrum count alone does not describe the number or diversity of compounds represented.
Arginine spectra were acquired using a quadrupole time-of-flight mass spectrometer in positive-ion mode at 20 eV collision energy.
Repeated measurements across instruments, laboratories, and conditions can characterize analytical variation and reproducibility.
The authors recommend reporting chemical coverage and acquisition metadata alongside spectral counts.

When assessing a spectral library, consider the number of unique molecules and authenticated compounds, not only the total number of spectra.

Report chemical classes, instrument and collision-energy coverage, ionization conditions, annotation confidence, and data provenance alongside spectral counts.
Link each spectrum to its sample source, acquisition conditions, and processing history.

Use repeated measurements across instruments, laboratories, collision energies, and sample conditions to assess analytical variation, reproducibility, and transferability.

A high spectral count may reflect repeated measurements of the same molecule rather than broad chemical coverage.
Under fixed acquisition conditions, additional measurements may become redundant.

Not applicable; this is a mass spectrometry resource and methods study.

No treatment or prescribing data are reported.

Interpret library size using both spectrum counts and measures of compound diversity and authentication.
Evaluate whether reference spectra match the analytical method and identification task, using acquisition and processing metadata.
Distinguish repeated measurements that characterize analytical variability from measurements that expand chemical coverage.