Simple and cost-effective determination of acrylamide in food products and coffee using gas chromatographymass spectrometry

Significance of Topic

Acrylamide is a toxic compound formed during high-temperature cooking of starchy foods via the Maillard reaction. It poses carcinogenic, neurotoxic and reproductive risks and is regulated by food safety agencies with benchmarks for various food categories. Reliable, cost-effective methods for routine acrylamide monitoring in products such as potato crisps, coffee and baked goods are essential for compliance and consumer protection.

Study Objectives and Overview

This study presents a streamlined workflow for the analysis of low-level acrylamide in food and coffee. It aims to replace time-consuming extraction and clean-up procedures with a simple acetonitrile extraction, followed by silylation derivatization and gas chromatography–single quadrupole mass spectrometry (GC–SIM/MS). Key goals include demonstrating method sensitivity, linearity, repeatability, robustness and practicality for routine analysis.

Methodology and Instrumentation

Sample Preparation:

• Grind 1 g of sample (food or coffee).
• Extract with 5 mL acetonitrile via ultrasonic bath (10 min) and vortex mixing (20 s).
• Centrifuge at 5752 g for 5 min; transfer 500 µL supernatant to vial.
• Add 100 µL MSTFA + 1% TMCS; heat at 70 °C for 60 min; cool to room temperature.

Instrument Configuration:

• GC: Thermo Scientific TRACE 1310 with TraceGOLD TG-WaxMS column (30 m × 0.25 mm × 0.25 µm), splitless injection, oven program from 50 °C to 250 °C.
• MS: Thermo Scientific ISQ 7000 with ExtractaBrite source and vacuum probe interlock, operated in timed Selected Ion Monitoring (t-SIM) mode.
• Quantification ion m/z 128; confirmation ion m/z 85; electron ionization at 70 eV.
• Data processed in Chromeleon CDS v7.2.

Main Results and Discussion

Chromatographic Performance:

• Sharp, symmetrical peaks for derivatized acrylamide (peak width ~4 s; tailing factor 0.91–1.01).
• Baseline separation from matrix interferences.

Linearity and Sensitivity:

• External calibration over 1–1000 ppb (5–5000 µg/kg) yielded R²=0.9993, average residual RSD 4.8%.
• Limit of identification (LOI) at 1 ppb (5 µg/kg) met EU identification criteria.

Matrix Effects and Selectivity:

• Silylation reduced co-extract interference compared to non-derivatized analyses, improving selectivity and signal intensity.
• Standard addition calibration for crisps and coffees achieved R² ≥ 0.9987 and residual RSD ≤ 4.0%, compensating for matrix bias.

Precision and Robustness:

• Repeatability study (n=16) on ground coffee spiked at 1000 µg/kg showed peak area RSD 2.9% across a 99-injection sequence without instrument maintenance.
• Mid-sequence vs. end-sequence injections yielded RSD 1.3%, confirming method robustness.

Sample Quantification:

• Measured acrylamide levels in unspiked samples: crisps ~129 µg/kg, instant coffee ~143 µg/kg, ground coffee ~197 µg/kg.
• Recovery and precision satisfactory for spiked levels at 1000 and 2000 µg/kg (n=3 replicates).

Benefits and Practical Applications

• Cost-effective workflow using acetonitrile extraction and silylation avoids expensive SPE and isotopically labeled standards.
• High throughput: minimal sample preparation, robust GC–MS analysis and streamlined data processing.
• Broad applicability across diverse food matrices (snacks, coffee, baked goods).

Future Trends and Opportunities

Advancements may include automated on-line derivatization, integration with high-resolution MS for even lower detection limits and expanded target panels for other process contaminants. Miniaturized sample prep and improved software algorithms for automated identification and quantification will enhance laboratory efficiency and regulatory compliance.

Conclusion

The described method demonstrates a simple, robust and cost-effective approach for routine acrylamide analysis in food and coffee. Key strengths include excellent sensitivity (LOI 5 µg/kg), linearity, repeatability (RSD ≤ 3%), robustness over extended sequences and reduced reliance on costly reagents. This workflow is well suited for high-throughput quality control and regulatory testing.

Used Instrumentation

• Thermo Scientific TRACE 1310 Gas Chromatograph
• TraceGOLD TG-WaxMS column (30 m × 0.25 mm × 0.25 µm)
• Thermo Scientific ISQ 7000 Single Quadrupole MS with ExtractaBrite source
• TriPlus RSH autosampler
• Chromeleon CDS software v7.2

Reference

1. Friedman M. Chemistry, Biochemistry, and Safety of Acrylamide. J Agric Food Chem. 2003;51(16):4504.
2. Mottram DS, Wedzicha BL, Dodson AT. Acrylamide formation in the Maillard reaction. Nature. 2002;419:448–449.
3. Regulation (EU) 2017/2158 on acrylamide in food. Food Standards Agency guidance.
4. SANTE/11813/2017 guidelines for pesticide residue identification.