CHRONECT LC-GC CHRONECT Workstation PAH

Importance of the topic

Polycyclic aromatic hydrocarbons (PAHs) are widespread environmental contaminants known for their carcinogenic potential. They form during incomplete combustion and pyrolysis processes and can contaminate food through environmental deposition or food processing methods such as roasting and smoking. Regulatory limits for marker PAHs vary across food matrices, with maximum levels for benzo[a]pyrene set between 1 and 6 µg/kg and combined PAH4 limits up to 35 µg/kg, driving the need for highly sensitive and reliable analytical approaches.

Study objectives and overview

The CHRONECT Workstation PAH integrates imPAHct multidimensional clean-up technology to deliver a fully automated workflow for routine PAH analysis in diverse matrices. The primary goals are to minimize sample handling time, maximize sample throughput, and maintain or exceed required sensitivity, precision and accuracy according to EFSA and other regulatory standards.

Methodology

Samples are first subjected to a rapid extraction and a brief manual treatment. The extract is introduced into a two-step HPLC clean-up sequence (LC-LC Clean-Up) monitored by UV detection. Purified fractions are automatically transferred to a GC-MS/MS system for final separation and quantification. This coupling yields chromatograms from both the HPLC purification stage and the GC-MS detection, providing real-time monitoring of the purification and analysis process.

Used instrumentation

• CHRONECT Robotic system with CTC PAL3 autosampler and CHRONOS control software
• Agilent 1260 Infinity II HPLC pump with UV detector and degasser
• Bruker EVOQ GC-TQ triple quadrupole mass spectrometer
• CHRONECT LC-GC interface for automated fraction transfer
• Pre-installed data acquisition and evaluation software

Key findings and discussion

The integrated LC-LC-GC-MS/MS workflow achieves limits of detection for EFSA-relevant PAHs between 0.01 and 0.02 µg/kg and limits of quantification below 0.06 µg/kg, surpassing regulatory requirements by up to a factor of 100 for infant formula. Method repeatability remains under 10% and total analysis time is approximately 45 minutes per sample. The multidimensional clean-up extends maintenance intervals and protects the GC inlet by effectively removing matrix interferences.

Benefits and practical applications

• Exceptional sensitivity with LODs well below regulatory limits
• High automation reduces manual workload and error risk
• Rapid turnaround supports high sample throughput
• Reduced consumable costs through reusable LC-LC clean-up
• Broad applicability to edible oils, vegetables, cocoa products, cosmetics and other complex matrices
• Modular design allows expansion to additional analytes

Future trends and potential applications

Automated multidimensional clean-up strategies are expected to become standard for regulated contaminant analysis. Future enhancements may include integration with high-resolution mass spectrometry or ion mobility for improved selectivity and throughput. Expanding the platform to other persistent organic pollutants or pharmaceutical residues will further extend its utility in food safety, environmental monitoring, cosmetic testing and quality control laboratories.

Conclusion

The CHRONECT Workstation PAH with imPAHct technology offers a turnkey, fully automated solution for routine PAH analysis, delivering high sensitivity, reproducibility and throughput while reducing operational costs. This platform ensures compliance with stringent regulatory standards and supports reliable contaminant monitoring across a wide range of sample types.