EA-IRMS: 13C and Simultaneous 18O and 2H Isotope Analysis in Ethanol with Thermo Scientific Delta V Isotope Ratio Mass Spectrometers

Importance of the Topic

Isotope analysis of ethanol using isotope ratio mass spectrometry has become an essential tool for verifying the quality, authenticity, and geographic origin of alcoholic products. By measuring stable isotopes of carbon, hydrogen, and oxygen in ethanol, laboratories can detect adulteration, exogenous sugar addition, and mislabeling in wines and spirits.

Study Objectives and Overview

This application note evaluates the performance of the Thermo Scientific FlashEA 1112 HT elemental analyzer coupled to a Delta V isotope ratio mass spectrometer for simultaneous measurement of δ13C, δ2H, and δ18O in ethanol. The study assesses precision, stability, throughput, and applicability to wine- and fruit-derived ethanol samples.

Methodology and Instrumentation

Carbon isotope (δ13C) analysis was performed by injecting 1 μL of purified ethanol into tin capsules and combusting in the FlashEA 1112 HT reactor. Hydrogen and oxygen isotopes (δ2H, δ18O) were determined by high-temperature conversion of 0.1 μL ethanol in a glassy carbon reactor. Sample peaks were diluted and split via the ConFlo interface, and raw data were blank-corrected and calibrated using internal and international standards.

Used Instrumentation

• Thermo Scientific FlashEA 1112 HT with combined combustion and high-temperature conversion reactor
• Thermo Scientific Delta V Isotope Ratio Mass Spectrometer
• Thermo Scientific ConFlo Universal Interface
• Thermo Scientific MAS 200R solids autosampler for tin capsules
• Thermo Scientific AS 3000 liquids autosampler for direct injections

Main Results and Discussion

• δ13C values showed precision better than ±0.1‰ and stable long-term performance without evaporation-induced fractionation.
• δ2H and δ18O measurements achieved precisions of 0.12‰ and 0.08‰ respectively, with the capability to process over 200 samples per 24 hours.
• Results for ethanol from wine and pineapple juice matched expected reference values, demonstrating method accuracy.

Benefits and Practical Applications

• Enables rapid, cost-effective, and reproducible multi-isotope analysis of ethanol.
• Facilitates authentication of wines and fermented beverages and detection of added sugars or mislabeling.
• High throughput and minimal preparation make it suitable for routine quality assurance in industrial and regulatory laboratories.

Future Trends and Potential Applications

Recent developments such as the EA IsoLink IRMS System promise further integration of combustion and high-temperature conversion techniques. Future directions include expanding multi-isotope workflows to other compounds, automated sample handling, and coupling with chromatographic separation for compound-specific analysis.

Conclusion

The combined FlashEA 1112 HT and Delta V IRMS setup delivers precise, reliable, and high-throughput measurement of δ13C, δ2H, and δ18O in ethanol. This universal EA-IRMS approach supports comprehensive authentication and quality control in the food and beverage industry.

References

1. Bréas O., Thomas F., Zeleny R., Calderone G., Jamin E., Guillou C., 2007. Performance evaluation of elemental analysis/isotope ratio mass spectrometry methods for the determination of the D/H ratio in tetramethylurea and other compounds – results of a laboratory inter-comparison. Rapid Communications in Mass Spectrometry 21:1555–1560.
2. Calderone G., Reniero F., Guillou C., 2006. 18O/16O measurements on ethanol. Rapid Communications in Mass Spectrometry 20:937–940.
3. Werner R., Brand W., 2001. Referencing strategies and techniques in stable isotope ratio analysis. Rapid Communications in Mass Spectrometry 15:501–519.
4. Commission Regulation (EEC) No 2676/90 of 17 September 1990 determining Community methods for the analysis of wines.
5. Commission Regulation (EC) No 822/97 of 6 May 1997 amending Regulation (EEC) No 2676/90 for wine analysis.
6. Commission Regulation (EC) No 440/2003 of 10 March 2003 amending Regulation (EEC) No 2676/90 for wine analysis.