Chromatography measures relative or absolute analyte amounts using differences in physical and chemical interactions with mobile and stationary phases.
This decision-focused guide explains the scientific measurement basis, when to use it, its limitations, sample amount considerations, competing methods, FDA-facing concerns, and common mistakes.
Chromatography separates analytes in a mixture based on their interactions with mobile and stationary phases. HPLC/UPLC, GC/headspace GC, and TLC can support potency, impurity, volatile, extractables/leachables, and reverse-engineering work.
Use chromatography for API assay, impurity profiling, additive analysis, extractables/leachables, volatile identification, patent example reproduction, method development/validation/transfer, and sample cleanup for MS or NMR.
Yes. We routinely identify trace impurities and can structurally characterize them with mass spectrometry and nuclear magnetic resonance spectroscopy. Preparative LC can be used when an impurity must be enriched or isolated before higher-confidence structure assignment, orthogonal confirmation, or follow-up impurity-control work.
Chromatography gives separation and response, not always identity. Coelution, matrix interference, detector response factors, sample instability, poor extraction, and reference-standard availability can limit interpretation.
Analytical chromatography often works with small amounts of material, but method development, extraction recovery, replicate testing, and impurity isolation may require more. Exact amount should be scoped against detection limit and matrix complexity.
LC-MS/GC-MS, NMR, FTIR/Raman, UV/Vis, elemental analysis, and crystallographic methods may compete or complement chromatography depending on whether the decision is assay, structure, identity, elemental impurity, or solid form.
FDA cares about specificity, accuracy, precision, linearity/range, robustness, system suitability, impurity response, reference standards, and lifecycle control under ICH Q2(R2)/Q14 principles.
Common mistakes include assuming a retention-time match proves identity, ignoring extraction recovery, overlooking coelution, using non-representative matrices for validation, and failing to connect chromatographic results to toxicology or CMC thresholds.
Triclinic uses chromatography to answer real-world questions about assay, impurities, degradants, residual solvents, extractables and leachables, cleaning residues, and lot-to-lot comparability. The technique is most useful when separation, detection, and sample preparation are matched to the material question, so chromatographic evidence can distinguish true chemical change from matrix effects, preparation artifacts, or unsuitable method conditions.
The table below lists the specific platforms, brands, models, software, detectors, and capability notes relevant to this service area.
| Instrument or platform | Brand, model, software, or detector | Additional capabilities and use |
|---|---|---|
| HPLC / UPLC platforms | Agilent 1100 and Agilent 1260 Infinity II systems with Chromeleon 7.2 software; diode-array, refractive-index, and light-scattering detectors | Assay, impurity profiling, additive analysis, extractables/leachables, purity, potency, method development, transfer, and validation. |
| Preparative LC impurity isolation | Preparative LC / HPLC fraction-isolation capability integrated with downstream MS and NMR characterization | Isolation or enrichment of trace impurity fractions for structure elucidation by mass spectrometry and nuclear magnetic resonance spectroscopy. |
| Gas chromatography / headspace GC | Thermo Electron Trace 1310 GC; GC/headspace workflows with FID where appropriate | Volatile and residual-solvent profiling, headspace-accessible contaminants, and complex-mixture separation. |
| LC/MS/MS coupling | Agilent 6460 Triple Quadrupole LC/MS/MS | Trace-level compound detection and quantitation following chromatographic separation. |
| High-resolution LC/MS coupling | Thermo Fisher Scientific Orbitrap Exploris 120 MS with Vanquish LC; HCD and in-source fragmentation; Orbitrap resolution up to 120,000 FWHM | Accurate-mass assignment, elemental-formula constraints, impurity/degradant ID, and high-confidence unknown identification. |
| GC/MS coupling | Thermo Fisher Scientific Thermo 8000 GC/MS in electron-impact mode with DB-5 column and thermal gradient | Volatile/semi-volatile unknown identification, residual-solvent confirmation, and library-searchable EI spectra. |
| TLC / screening chromatography | Thin-layer chromatography workflows | Rapid qualitative separation checks, reaction monitoring, method scouting, and fraction-screening support. |
This example summarizes how chromatographic separations are used to convert complex mixtures into decision-ready information. The legacy Triclinic chromatography page identifies routine project types including actives quantitation, additive analysis, extractables and leachables, unknown volatile identification, reverse engineering, prior-art reproduction, infringement analysis, assay and impurity analysis, contaminant identification, and quantitative method development, transfer, and validation. The table below turns those use cases into a project-scoping view.
| Chromatography use case | Decision supported |
|---|---|
| Actives quantitation / potency | Measure relative or absolute API amount when the analyte can be extracted and separated from the matrix. |
| Assay and impurity analysis | Support purity, degradant, impurity, or specification-related questions when chromatographic specificity is required. |
| Extractables and leachables | Screen, identify, or quantify compounds that may migrate from packaging, devices, or contact materials. |
| Unknown volatile identification | Use GC or headspace GC when volatility or residual solvent behavior is central to the question. |
| Reverse engineering / prior-art reproduction | Compare formulations, reproduce patent examples, or support infringement and non-infringement questions. |
| Method development, transfer, and validation | Move from exploratory separation to controlled quantitative testing when the method must support release, stability, or regulatory decisions. |
These examples include technical resources, regulatory guidances, or literature relevant to the technique. Download buttons are placed at the bottom-left of each example.
Author: Gary C. George III, Jason Vanlerberghe, and Stephan X.M. Boerrigter
Publication date: Q1 2026
Abstract: This Triclinic white paper explains a hybrid workflow in which HRMS provides accurate-mass/formula constraints and MicroED provides crystallographic structure evidence for trace impurities that may be difficult to isolate in amounts needed for traditional methods.
Author: International Council for Harmonisation / FDA
Publication date: 2024
Abstract: FDA notes that ICH Q2(R2) and Q14 describe validation and development principles for analytical procedures used to assess drug substance and drug product quality. These guidances frame FDA expectations for specificity, accuracy, precision, range, robustness, lifecycle management, and fit-for-purpose method evidence.
Author: Maria Victoria Silva Elipe
Publication date: 2024
Abstract: This RSC book chapter describes NMR applications during drug-substance and drug-product development, including molecular characterization, identity, formulation-related questions, and regulatory-support contexts for pharmaceutical materials.
Use this technique when its evidence better matches the sample, matrix, or development decision.
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View techniqueUse this technique when its evidence better matches the sample, matrix, or development decision.
View techniqueUse this technique when its evidence better matches the sample, matrix, or development decision.
View techniqueUse this technique when its evidence better matches the sample, matrix, or development decision.
View techniqueUse this technique when its evidence better matches the sample, matrix, or development decision.
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Tell Triclinic what sample you have, what decision the data must support, what prior data are available, and whether cGMP, release, validation, or regulatory documentation is required.
