LC-IRMS: Enhanced workflow for honey analysis using the new LC IsoLink II IRMS System

Importance of the topic

Carbon isotope ratio analysis by LC IRMS is a key tool for verifying the authenticity of honey and detecting adulteration. This method relies on tracing natural variations in 13C 12C ratios to distinguish genuine products and protect consumers and producers from fraud.

Study objectives and overview

This study evaluates an enhanced LC IsoLink II IRMS workflow designed to streamline high throughput honey analysis. The goal was to demonstrate improved automation, reduced maintenance, and robust performance for routine food authentication in quality control labs.

Methodology

• Sample preparation: honey dissolved in water, diluted 1 to 100, filtered and kept at 10 C
• Separation: isocratic HPLC with water on Shodex Sugar SC 1011 column at 60 C, 0.3 mL per minute flow, 10 microliter injection
• Oxidation: post column mixing with sodium persulfate and phosphoric acid 0.1 mL per minute each in conversion reactor to produce CO2
• Detection: degassed CO2 measured by DELTA Q IRMS via He carrier and ConFlo IV interface
• Data control: Qtegra ISDS software for method setup, data acquisition and quality control alignment

Used instrumentation

• LC IsoLink II Conversion Interface fully integrated with Vanquish Core HPLC
• Vanquish Core Dual Pump C with electronic flow regulation
• DELTA Q isotope ratio mass spectrometer
• ConFlo IV Universal Interface for automated reference gas handling
• Qtegra ISDS and Chromeleon chromatography data systems

Main results and discussion

The system operated continuously on three units over three months, analyzing over 1500 samples each. Backflush maintenance and cartridge reactor swaps maintained stable HPLC pressure and baseline. Carbon isotope measurements of glucose, fructose, disaccharides and trisaccharides showed precision below 0.14 per mil and linearity within 0.006 to 0.018 per mil per nanoamp across the complete dynamic range.

Benefits and practical applications

• Automated cleaning reduces downtime and extends reactor life
• High throughput and minimal fractionation free analysis
• Integrated software ensures data integrity, traceability and compliance with 21 CFR Part 11
• Suitable for routine honey authentication in QA QC and regulatory environments

Future trends and possibilities

Advances may include broader application to other food matrices, multielement isotope analysis, enhanced automation and predictive maintenance, and tighter integration with LIMS and data analytics platforms to support large scale food authenticity screening.

Conclusion

The LC IsoLink II IRMS System demonstrates significant improvements in robustness, reliability and ease of use for carbon isotope analysis of honey. Its automated workflows, preventive maintenance and precise isotope ratio measurements empower laboratories to detect adulteration efficiently and support routine food authentication.

Reference

Thermo Fisher Scientific Technical Note TN001996 2023