
— SIRIUS Solutions for
Impurity, E&L and contaminant screening
Why impurity and E&L teams use SIRIUS
E&L libraries and suspect lists only cover what someone has already catalogued. Non-intentionally added substances, reaction products between packaging and product, and manufacturing by-products rarely have a reference spectrum, and exact mass alone cannot tell isomers apart.
SIRIUS works from the fragmentation spectrum itself. It proposes molecular formulas from isotope and fragmentation patterns, predicts a molecular fingerprint, and searches it against PubChem, your in-house databases or candidate structures you generate yourself. When nothing fits, it predicts the compound class or builds structures de novo.
Profile
Screen
Trace
Most of what migrates, degrades or leaches was never in a database
Molecular formula annotation from isotope pattern and fragmentation tree, without needing a matching entry in any spectral library.
Compound class prediction narrows down a chemical hypothesis, such as a phthalate ester or a paraben, before a structure is confirmed.
De novo structure generation proposes structures for compounds that exist in no database at all.
Food contact materials and E&Ls
Custom structure databases turn your suspect lists and additive inventories into a searchable candidate space.
Compound class prediction assigns unknowns to classes such as phthalate esters or parabens without any database.
Spectral library matching against your in-house E&L libraries and curated public spectra.
Field example

More SIRIUS discoveries
114 chemicals migrating from food packaging identified, including hazardous plasticizers and persistent non-intentionally added substances.
Pharmaceutical impurities and degradants
During synthesis, formulation and storage, an active pharmaceutical ingredient can co-exist with synthesis-related impurities or degrade through hydrolysis, oxidation or photolysis. Forced degradation and stability studies produce many closely related structures, and almost none of them have a reference spectrum. SIRIUS lets you build your own search space: generate candidate degradants with custom reactions or BioTransformer, search them with the predicted fingerprint, and check each hit against the spectrum.
Transformation product prediction to automatically generate bio-transformation products, as well as custom chemical reactions.
Structure Sketcher lets you modify a candidate and instantly re-score it against the predicted fingerprint.
Substructure validation with analog hits shows whether the shared core with a known compound explains the spectrum.
Application note
More SIRIUS discoveries
Drug metabolites and drugrelated impurities in human plasma identified without reference standards and a priori knowledge of first- and second-pass drug metabolism.
PFAS and persistent contaminants
PFAS detection strategy predicts fluorine and expands the formula search space to high-fluorine candidates.
Search and filter by PFAS tags, confidence ranges and executed annotation methods.
Homologous Series view groups related molecules in a Kendrick mass defect plot with a repeating unit of your choice.
Expansive search falls back to PubChem when your databases have no good candidate.
Field example: persistent offshore discharges
Field example: fluoropolymer production
Researchers monitored air downwind of a fluoropolymer plant. Suspect screening with SIRIUS revealed a homologous series of at least seven hydrogen-substituted perfluoroalkyl carboxylic acids, suspected PTFE polymerization by-products; three were confirmed with authentic standards.
More SIRIUS discoveries
Previously undetected chemicals with potential estrogenic activity in drinking water from regions with high breast cancer incidence.
Weathered tire wear particles and crumb rubber yielded 572 prioritized transformation products, including novel oligomers of the antioxidant TMQ and 45 transformation products never reported before.
Agrochemical and synthesis impurities
Network-enhanced formula annotation uses related compounds in the same sample set.
Field example
Researchers used SIRIUS network-enhanced formula annotation and molecular structure annotation in an impurity profiling protocol. They elucidated 18 structurally related impurities and grouped them by substitution pattern; 14 of them were reported for the first time.
More SIRIUS discoveries
A 6-year groundwater study traced legacy pesticides such as simazine, along with flame retardants and insect repellents, and showed that extreme weather can remobilize them down to 90 m.
Exposure biomonitoring
Field example
More SIRIUS discoveries
Potentially allergenic transformation products of tattoo pigments identified in new online-LC-EC-MS approach.
Urine of women with ovarian malignancies showed significantly higher levels of six exposure biomarkers: two phthalates, two pesticides, a UV filter and an industrial by-product.
Annotations you can defend in an investigation report
Confidence score
rates how likely a structure hit is exactly correct, or highly similar to the true structure.
Substructure annotation
links fragment peaks and neutral losses to parts of a candidate, so it can be checked peak by peak and exported as a figure.
Identity and analog library matches
cross-check results against reference spectra and verify shared structural cores of related compounds.
Protection against suspect blindness
shows the best library match and the best structure hit side by side.
Feature and spectral quality metrics
flag weak or ambiguous features before they reach a report.
Exportable scores
travel with every result into summary tables for documentation and review.
From extraction study to report, at production scale
Parameter-free LC-MS pre-processing
Feature detection, alignment and adduct detection with quality metrics for fast prioritization.
GUI, CLI and REST API
One project database behind all three: automate runs via CLI or API, then inspect them in the GUI.
Software integrations
Integrations with MassHunter, mzmine and Compound Discoverer keep SIRIUS inside existing workflows.
Computation presets
Save validated configurations and reuse them for every recurring study type.
Structured exports
Summary tables with scores, ChemVista-ready files and publication-quality SVG figures.
Searching hundreds of thousands of candidates, automatically
SIRIUS has been applied across many impurity, E&L and contaminant studies
Over 4,000 compounds annotated and hidden toxic contaminants and bioactives semi-quantified in bee pollen supplements.
33 emerging contaminants, including antioxidants and industrial surfactants, found in tap water from 12 countries; 25 for the first time.
Plastic leachates, UV filters and wastewater-derived inputs uncovered inside a protected Ramsar wetland.
Previously overlooked toxic drivers in air, including 2-indanone and 2-vinylpyridine, linked to lung cell toxicity.
A MS2-based priority score built on SIRIUS fingerprints, MS2Tox and MS2Quant cut wastewater non-target datasets by 81 to 99% before identification.
See what SIRIUS finds in your data
Related solutions
Pharmaceuticals and Drug Discovery
Drug leads, metabolites and degradants
Dietary compounds, residues and contaminants
Environmental and water analysis
Unknown pollutants and their transformation products
Known and novel PFAS in environmental and consumer samples
Explore more on the blog
Browse related discoveries and application notes by topic.
For Research Use Only. Not for use in diagnostic procedures.




