15th Multidimensional Chromatography Workshop Abstract book

Importance of the Topic

Comprehensive two-dimensional separations (GC×GC and 2D-LC) address the intrinsic complexity of modern analytical challenges. They deliver unmatched resolving power to dissect intricate mixtures arising in environmental monitoring, petrochemical quality control, pharmaceutical development, forensic investigations, and biomedical diagnostics. By significantly enhancing peak capacity and selectivity over conventional one-dimensional methods, multidimensional chromatography enables detection, identification, and quantification of trace and matrix-embedded constituents, supporting more informed decisions in research, quality assurance, and regulation.

Objectives and Study Overview

This body of work examines the advantages, limitations, and method development strategies for two-dimensional gas chromatography (GC×GC) and liquid chromatography (2D-LC, LC×SFC) across a wide spectrum of applications. Key aims include overcoming barriers to adoption in non-academic laboratories, establishing standard reference mixtures, advancing trap-and-recollect sampling for breath and environmental studies, exploring novel modulation and interface technologies, and applying advanced data analytics for biomarker discovery and fingerprint profiling.

Methodology and Instrumentation

• GC×GC approaches employ flow-based (direct) or flow-switch modulation, pairing polar and nonpolar columns for enhanced orthogonality. Hydrogen carrier gas is demonstrated in high-flow configurations, and flow-modulated systems achieve long secondary separation windows (e.g., 120 s) without complex cooling or valve matrices.
  
• Two-dimensional LC configurations integrate reversed-phase, hydrophilic interaction, ion-exchange, and supercritical fluid chromatography (SFC) modes. Automated multi-column valve manifolds enable rapid screening of diverse stationary phases without manual intervention.
  
• Detection employs time-of-flight mass spectrometry (TOFMS) for high-resolution, accurate-mass data, flame ionization detection (FID) for robust quantitation, atmospheric pressure ionization interfaces (e.g., SICRIT plasma source), and dual EI/FI/FD sources to characterize oligomers and complex oils.
  
• Sample collection utilizes thermal desorption tubes for breath and environmental samplers, passive silicone samplers for river water, sorbent trapping for body-odor VOCs, and wipe sampling for aircraft cabin surfaces. On-tube recollection capabilities and cold-chain storage studies validate long-term analyte stability.
  
• Advanced chemometrics include tile-based Fisher ratio contrasts for simultaneous discovery of multiple processes, unsupervised and supervised PCA, PLS regression, non-target screening workflows (MS-DIAL, SIRIUS, FBMN), computer-vision assisted template alignment for group-type analysis, and web-based simulation tools for method development.
  

Main Results and Discussion

• GC×GC-TOFMS differentiates isomeric and trace compounds in fuels, essential oils, athletics of pyrolysis oils, and plastic-derived alternative fuels, revealing families of oxygenates, heteroatom species, and multi-branched paraffins not visible in 1D separations.
  
• Standard mixtures for GC×GC performance assessment show robust separation of volatile homologues; PLOT columns with thin stationary films extend operable boiling point ranges for combined gas analyses.
  
• LC×SFC coupling overcomes mobile phase incompatibility via in-line dilution or make-up flows, enabling trap-free, reliable on-line modulation for biomolecule and small-molecule characterization.
  
• Breath and environmental studies validate passive and active sampling techniques, demonstrating stability of VOC profiles over weeks under refrigeration or mail shipment, and enabling pooled QC preparation by tube recollection.
  
• Biological applications identify volatile signatures of cystic fibrosis pathogens, coffee sensory defects, acute respiratory exacerbations, and fingerprint aging, achieving predictive models of defect markers (e.g., pyrazines) and degradation kinetics.
  
• Data-handling innovations streamline GC×GC workflows, democratizing access to alignment, deconvolution, and multivariate reporting, shifting from opaque vendor software to open-source, Python-based toolchains.
  

Benefits and Practical Applications

• Enhanced separation and detection of trace contaminants in regulatory and industrial QA/QC labs improves compliance with environmental and automotive emission directives via holistic water and fuel analyses.
  
• Pharmaceutical process development gains rapid impurity profiling and peak purity assessments in peptide, oligonucleotide, and antibody modalities, reducing time-to-clinic and ensuring product quality.
  
• Forensic and security sectors benefit from more robust arson accelerant characterization, contaminant profiling of surfaces, and accelerated method validation for courtroom-grade evidence.
  
• Biomedical metabolomics and volatolomics utilize non-invasive breath and body-odor monitoring, enabling personalized diagnostics, disease screening, and longitudinal health assessments.
  

Future Trends and Opportunities

• Broader adoption in regulatory environments through standardized, validated protocols for multidimensional separations.
  
• Integration of on-the-fly data analytics and machine learning directly into chromatographic software, supporting real-time decision making.
  
• Further refinement of ambient ionization and in-line modulation hardware to expand applicability to ultra-high throughput and high-boiling-point matrices.
  
• Open-data initiatives and community-driven benchmarks to enable transparent comparison of software algorithms and method performance.
  
• Emergence of modular, microfluidic platforms for portable 2D separations in field applications.
  

Conclusion

Multidimensional chromatographic techniques have matured into indispensable tools across scientific, industrial, and regulatory domains. Advances in modulation hardware, interface design, sampling strategies, and data processing are lowering barriers to entry, enhancing robustness, and unlocking the full potential of GC×GC and 2D-LC separations. Collaboration between instrumentation vendors, software developers, and end users will accelerate standardization and drive novel applications in environmental stewardship, healthcare, pharmaceuticals, and beyond.