Analysis of Benzophenone and 4-Hydroxybenzophenone in Breakfast Cereal

Significance of the Topic

Migration of benzophenone and its metabolite 4-hydroxybenzophenone from food packaging into cereal products poses regulatory and health concerns. Establishing a rapid, reliable analytical workflow is essential for monitoring compliance with the specific migration limit of 0.6 mg/kg, ensuring food safety and consumer protection.

Objectives and Study Overview

This study aimed to develop and validate a QuEChERS-based sample preparation protocol coupled with GC-MS for the quantitative determination of benzophenone and 4-hydroxybenzophenone in breakfast cereal. The work compared recovery, precision, and analysis time against the conventional liquid-liquid extraction approach described by the Food Standards Agency.

Methodology and Sample Preparation

The modified EN15662 QuEChERS procedure involved two stages:

• Extraction: Five grams of homogenized, hydrated cereal were suspended in 10 mL water, spiked with analyte standards, then extracted with 10 mL acetonitrile in presence of a salt mixture (MgSO4, NaCl, trisodium citrate dihydrate, disodium citrate sesquihydrate). After vigorous shaking and centrifugation, the organic layer was collected.
• Dispersive SPE Cleanup: Five milliliters of the acetonitrile extract were transferred to a dSPE tube containing MgSO4, PSA, silica, and C18 sorbents. The mixture was shaken, centrifuged, and a cleaned extract was spiked with internal standard prior to GC vial transfer.

This workflow reduced solvent consumption and preparation time to approximately 2 hours compared to traditional methods requiring up to 18 hours.

Used Instrumentation

The analytical system comprised:

• Gas Chromatograph: Thermo Scientific TRACE GC Ultra with TraceGOLD TG-17MS column (30 m×0.25 mm×0.25 μm).
• Mass Spectrometer: Thermo Scientific ISQ operating in SIM mode (EI, 70 eV), monitoring quantifier ions for benzophenone (m/z 182) and 4-hydroxybenzophenone (m/z 198) alongside deuterated and fluoro-labeled internal standards.
• Autosampler: Thermo Scientific TriPlus RSH with 1 µL splitless injection.

Main Results and Discussion

Calibration curves for both analytes exhibited excellent linearity (R2>0.999). At a spiked level of 0.6 mg/kg, mean recoveries were 101.7% (RSD 2.3%) for benzophenone and 82.3% (RSD 4.6%) for 4-hydroxybenzophenone. SIM chromatograms demonstrated clear baseline separation and minimal matrix interference, confirming robustness of the QuEChERS-GC-MS approach.

Practical Benefits and Applications

The developed method offers:

• Speed: High throughput with batch preparation in under 2 hours.
• Cost efficiency: Reduced solvent and sorbent usage.
• Accuracy and Precision: High recoveries with low variability.
• Versatility: Applicable to polar and non-polar migrants in complex food matrices.

Future Trends and Applications

Advancements may include integration with high-resolution mass spectrometry for non-targeted screening of emerging migrants, miniaturized or automated QuEChERS formats for field testing, and expansion to other food types and packaging contaminants to support comprehensive food safety surveillance.

Conclusion

The QuEChERS-GC-MS method provides a rapid, reliable, and reproducible workflow for monitoring benzophenone migrants in cereals, aligning with regulatory requirements and delivering operational advantages over conventional extraction techniques.

Reference

1. Food Standards Agency. Survey of benzophenone and 4-hydroxybenzophenone migration from food packaging into foodstuffs. Number 18/06, November 2006.
2. Anastassiades M, Lehotay SJ, Stajnbaher D, Schenck FJ. J AOAC Int. 2003;86:412.
3. European Standard EN15662:2008. Foods of plant origin – Determination of pesticide residues using QuEChERS.