DETERMINATION OF ACRYLAMIDE IN COFFEE BY LC-MS/MS (RAFA)

Significance of the Topic

Coffee roasting drives complex chemistry, producing desirable flavour compounds alongside the unwanted contaminant acrylamide. Because acrylamide is water-soluble, it transfers into brewed coffee, raising concerns about dietary exposure and carcinogenic risk. Recent regulations set benchmark levels for acrylamide in coffee, making reliable analytical methods essential for quality control and regulatory compliance.

Objectives and Overview

This study aims to develop and validate a fast, sensitive LC-MS/MS method for the quantitation of acrylamide in roasted and instant coffee. Key goals include achieving robust retention of the polar analyte, minimizing matrix effects, and covering regulatory concentration ranges from benchmark limits up to high levels in coffee substitutes.

Methodology and Instrumentation

Sample Preparation and Extraction

• Modified QuEChERS protocol applied to 1 g homogenized coffee samples
• Incorporation of isotopically labelled internal standard (acrylamide-d3) before extraction for correction of variability
• Dispersive SPE (dSPE) clean-up followed by evaporation and reconstitution in 0.1 % formic acid in LC–MS water

Chromatographic and Mass Spectrometric Conditions

• UPLC I-Class system with HSS C18 SB 1.8 µm column
• Gradient optimized for polar retention at 0.2 mL/min flow
• Detection on Waters Xevo TQ-S micro in positive ESI mode, monitoring quantifier and qualifier transitions for acrylamide and d3 internal standard

Main Results and Discussion

Retention and Sensitivity

• Excellent retention of acrylamide achieved with simple reversed-phase gradient
• Limit of quantitation meets regulatory requirements, with linear calibration (r2 = 0.999) over an extended range

Accuracy and Precision

• Analysis of FAPAS coffee reference (assigned 249 µg/kg) yielded 244 µg/kg (RSD 4.6 %, bias –2.0 %)
• Method validated in accordance with EU Regulation 2017/2158, demonstrating robust repeatability and accuracy

Matrix Scope

• Method applicability confirmed across diverse processed foods, including coffee, potato products, baby foods and bread
• Simple clean-up supports reliable quantitation against solvent-based calibration

Benefits and Practical Applications

This LC-MS/MS approach offers:

• Rapid turnaround for routine QA/QC testing of coffee products
• High sensitivity and selectivity for low-level acrylamide monitoring
• Compliance with regulatory benchmarks for food safety

Future Trends and Opportunities

Ongoing developments may include:

• Automation of sample preparation to increase throughput
• Use of alternative stationary phases or hydrophilic interaction chromatography to enhance polar retention
• Integration of high-resolution mass spectrometry or ion mobility for expanded untargeted screening
• Adoption of greener solvents and miniaturized extraction workflows

Conclusion

The presented LC-MS/MS method, based on modified QuEChERS extraction and isotopic dilution, provides a sensitive, precise and regulatory-compliant approach for acrylamide analysis in coffee. Its broad applicability and validated performance support comprehensive food safety testing and quality assurance in both research and industrial 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 Function. 2012;3(9):892–900.
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):20–24.
3. European Commission. Commission Regulation (EU) 2017/2158 establishing mitigation measures and benchmark levels for the reduction of acrylamide in food. Official Journal of the European Union. 2017.