Extraction and Analysis of Polycyclic Aromatic Hydrocarbons in Infant Formula

Significance of topic

Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous environmental contaminants with known carcinogenic and mutagenic properties. Infant formula, being a high‐lipid powder, can accumulate PAHs during production and storage, posing potential health risks for infants. Regulatory bodies such as the European Commission and WHO have established strict limits for PAHs in infant foods, driving the need for sensitive, reliable analytical methods.

Objectives and overview

This study aimed to develop and validate a streamlined sample preparation and analysis protocol for quantifying PAHs in infant formula. Key goals included efficient lipid removal, low detection limits aligned with EU Regulation 835/2011, and the evaluation of hydrogen (H₂) as a carrier gas in GC/MS to address helium scarcity.

Methodology and instrumentation

The workflow combined solvent extraction of dissolved formula powder with enhanced lipid cleanup using Agilent Captiva EMR–Lipid cartridges. Aqueous dissolution (2 mL water per 2 g powder) was followed by extraction with acetonitrile/ethyl acetate and QuEChERS salts. The EMR–Lipid pass‐through removed triglycerides, after which eluates were back‐extracted into isooctane for GC/MS compatibility.

Instrumental analysis utilized an Agilent 8890 GC coupled to a 5977C GC/MSD equipped with the HydroInert source. A J&W DB‐EUPAH column provided chromatographic separation of 16 priority PAHs. Hydrogen at 0.9 mL/min constant flow served as the carrier gas. Selective‐ion monitoring (SIM) enhanced sensitivity, and matrix‐matched calibration (0.1–20 ppb) enabled quantitation below 1 µg/kg.

Results and discussion

Optimizing water volume for powder dissolution was critical: a lower 2 mL volume yielded >70% recoveries for heavy PAHs, while 10 mL reduced extraction efficiency. Method recoveries ranged 60–95% for eight key PAHs at spiking levels of 1–50 ng/g, with relative standard deviations below 20%, except for benzo[k]fluoranthene at 1 ng/g (54%) and benzo[ghi]perylene (35% RSD). The HydroInert source with H₂ maintained sensitivity and prevented hydrogenation issues.

Benefits and practical applications

• High selectivity cleanup in fatty matrices via EMR–Lipid cartridges
• Reduced analysis cost and resource dependence by substituting H₂ for He
• Compliance with stringent regulatory limits for PAH4 and benzo[a]pyrene
• Adaptability to routine QA/QC and research laboratories

Future trends and possibilities

Emerging directions include automating EMR‐based workflows with robotic platforms, expanding hydrogen‐based GC/MS applications to other contaminant classes, and integrating tandem mass spectrometry for even greater sensitivity. Machine‐learning algorithms could further refine signal‐to‐noise discrimination in complex matrices.

Conclusion

The described method offers a robust, efficient approach to PAH determination in infant formula, combining targeted lipid removal, isooctane back‐extraction, and GC/MS with hydrogen carrier gas. Performance meets EU requirements, supporting routine monitoring and safeguarding infant health.

References

1. Agilent Technologies. Inert Plus GC/MS System with HydroInert Source; Technical Overview, Publication 5994-4889EN, 2022.
2. Sampaio G.R. et al. Polycyclic Aromatic Hydrocarbons in Foods: Biological Effects, Legislation, Occurrence, Analytical Methods, and Strategies to Reduce Their Formation. Int. J. Mol. Sci. 2021, 22(11), 6010.
3. European Commission. Food for Infants and Young Children. https://food.ec.europa.eu/safety/labelling-and-nutrition/specific-groups/food-infants-and-young-children_en.
4. European Commission. Commission Regulation (EU) 835/2011 of 19 August 2011 Amending Regulation (EC) 1881/2006 as Regards Maximum Levels for Polycyclic Aromatic Hydrocarbons in Foodstuffs. Official Journal of the European Union L 215/4, 08.2011.
5. Zhao L.; Wong D. Determination of 19 Polycyclic Aromatic Hydrocarbon Compounds in Salmon and Beef. Agilent Technologies Application Note 5994-0553EN, 2020.
6. Akinpelu A.A. et al. Polycyclic Aromatic Hydrocarbons Extraction and Removal from Wastewater by Carbon Nanotubes: A Review of the Current Technologies, Challenges and Prospects. Process Saf. Environ. Prot. 2019, 122, 68–82.
7. Purcaro G.; Barp L.; Moret S. Determination of Hydrocarbon Contamination in Foods: A Review. Anal. Methods 2016, 8(29), 5755–5772.