CAMERA

CAMERA annotates and organizes compound spectra from liquid chromatography–mass spectrometry (LC-MS) metabolomics data to propose accurate compound masses and annotate isotopes, adducts, and fragments using spectral information from positive and negative ion modes.

Key Features:

• Automated compound-spectrum extraction: Extracts compound spectra from complex LC-MS datasets.
• Isotope and adduct peak annotation: Employs rule-based algorithms to annotate isotope peaks and adducts.
• Accurate mass proposal: Proposes accurate compound masses within highly complex datasets.
• Opposite ion-mode integration: Integrates spectral information from positive and negative ion modes to improve annotation accuracy and coverage.
• Extracted ion chromatogram (EIC) correlation: Uses EIC correlation to tag unknown adducts and fragments.
• Isotope validation: Implements isotope validation mechanisms for annotated peaks.

Scientific Applications:

• LC-MS-based metabolomics: Applied to metabolomics experiments using liquid chromatography–mass spectrometry for compound annotation.
• Plant and complex biological matrices: Demonstrated utility in complex matrices such as plant samples.
• Benchmarking against manual annotation: In comparative studies against manually defined annotations, extracted accurate masses for 89.7% and 90.3% of annotatable compounds in positive and negative ion modes, respectively.

Methodology:

Integrates algorithms that extract compound spectra, apply rule-based annotation of isotopes and adducts, perform isotope validation, and employ extracted ion chromatogram (EIC) correlation to tag unknown adducts and fragments using spectral information from both positive and negative ion modes.