DETERMINATION OF ACRYLAMIDE IN COFFEE BY LC-MS/MS

Significance of the topic

The formation of acrylamide during coffee roasting presents a significant health concern as it is classified as a probable human carcinogen (IARC Group 2A). Acrylamide can readily migrate from coffee grounds into the brewed beverage, and regulatory bodies such as the European Union have set benchmark levels under Regulation 2017/2158 to mitigate consumer exposure.

Objectives and study overview

This work aims to develop and validate a robust LC-MS/MS method for the accurate quantitation of acrylamide in roasted coffee. The method addresses analytical challenges including retention of a polar analyte, matrix complexity, and a broad concentration range from trace levels to regulatory limits.

Methodology

Sample preparation and extraction:

• 1 g of homogenized ground coffee was extracted using a modified QuEChERS protocol.
• Acrylamide-d3 was spiked as an isotopically labeled internal standard to correct for extraction and analysis variability.
• Dispersive SPE cleanup (dSPE) was applied, followed by evaporation to dryness and reconstitution in 0.1 % formic acid in LC–MS grade water.

Used instrumentation

Liquid chromatography:

• ACQUITY UPLC I-Class system with ACQUITY UPLC HSS C18 SB column (1.8 µm).
• Column temperature 30 °C, sample temperature 10 °C, flow rate 0.2 mL/min.
• Mobile phases: water with 0.1 % formic acid (A) and methanol (B).

Mass spectrometry:

• Xevo TQ-S micro tandem quadrupole MS in positive ESI mode.
• MRM transitions for acrylamide: m/z 72.05 > 55.10, 72.05 > 44.10, 72.05 > 27.15; for acrylamide-d3: m/z 75.00 > 58.10.
• Desolvation temperature 600 °C, source temperature 150 °C, cone gas 50 L/hr, desolvation gas 1000 L/hr.

Main results and discussion

The method demonstrated excellent linearity over 0.5–2500 ng/mL with r² = 0.999 (1/x weighting). Back-calculated residuals were within ±20 %. Chromatograms of QuEChERS extracts before and after dSPE cleanup showed markedly cleaner baselines post-cleanup. Analysis of a FAPAS coffee reference (assigned 249 µg/kg) yielded a measured value of 244 µg/kg, corresponding to a bias of –2.0 % and RSD of 4.6 %.

Benefits and practical applications

The developed protocol offers high sensitivity and selectivity for compliance testing, a streamlined sample cleanup suitable for diverse food matrices, and rapid throughput for routine quality control in the coffee industry.

Future trends and applications

Potential future developments include:

• Automation of the QuEChERS workflow to further increase laboratory throughput.
• Coupling with high-resolution mass spectrometry for non-targeted screening of process contaminants.
• Extension of the method to other complex matrices such as alternative coffee blends, beverages, and novel food products.

Conclusion

This validated LC-MS/MS method enables precise and accurate quantitation of acrylamide in coffee, meeting EU benchmark requirements and providing a robust analytical tool for food safety laboratories.

References

1. Kocadağlı T, Göncüoğlu N, Hamzalıoğlu A, Gökmen V. In depth study of acrylamide formation in coffee during roasting: role of sucrose decomposition and lipid oxidation. Food Funct. 2013;3(9):939–947.
2. Guenther H, Anklam E, Wenzl T, Stadler R. Acrylamide in coffee: review of progress in analysis, formation and level reduction. Food Addit Contam. 2007;24(sup1):22–36.
3. European Commission. Regulation (EU) 2017/2158 of 20 November 2017 establishing mitigation measures and benchmark levels for acrylamide in food. Official Journal of the European Union. 2017.