Analysis of Benzophenone and 4-Hydroxybenzophenone in Breakfast Cereal

Significance of the Topic

The migration of benzophenone and its hydroxy derivative from packaging into breakfast cereals poses a potential food safety risk. Regulatory bodies enforce a specific migration limit of 0.6 mg/kg for benzophenone, making reliable analytical methods essential for compliance and consumer protection.

Objectives and Study Overview

This application note evaluates a modified QuEChERS dispersive SPE sample preparation coupled with GC-MS for quantifying benzophenone and 4-hydroxybenzophenone in breakfast cereal. It also assesses the chromatographic performance of the Thermo Scientific TraceGOLD TG-17MS column.

Methodology

The sample preparation follows a two-stage EN15662 QuEChERS protocol:

• Extraction Stage: Hydrate and homogenize 5 g of cereal with 10 mL water, spike with analyte standards, add 10 mL acetonitrile and a salt mixture (magnesium sulfate, sodium chloride, tribasic and dibasic sodium citrate), vortex, sonicate, then centrifuge.
• Dispersive SPE Cleanup: Transfer 5 mL of the acetonitrile extract to a tube containing magnesium sulfate, PSA, silica and C18 sorbents, shake, centrifuge, then collect the cleaned extract and add internal standards.

This streamlined workflow completes in approximately 2 hours with reduced solvent consumption compared to traditional liquid–liquid extraction.

Instrumentation

The analytical system comprised:

• GC: Thermo Scientific TRACE GC Ultra with TraceGOLD TG-17MS column (30 m × 0.25 mm × 0.25 µm), helium carrier gas, oven ramp from 80 °C to 280 °C.
• MS: Thermo Scientific ISQ mass spectrometer, electron ionization at 70 eV, operated in selected ion monitoring (SIM) mode.
• Autosampler: Thermo Scientific TriPlus RSH.

Main Results and Discussion

Calibration curves for both analytes demonstrated excellent linearity (R² > 0.999) over 50–1000 ng/mL. Recovery experiments at a 0.6 mg/kg spiking level yielded 101.7% for benzophenone (RSD 2.3%) and 82.3% for 4-hydroxybenzophenone (RSD 4.6%). SIM chromatograms confirmed clear peak resolution and minimal matrix interferences.

Benefits and Practical Applications

The QuEChERS-GC-MS approach offers:

• High throughput: multiple samples processed within 2 hours.
• Reduced solvent and sorbent usage compared to conventional methods.
• Accurate and reproducible recoveries for both polar and nonpolar analytes.
• Enhanced safety by eliminating chlorinated solvents.
• Robustness against matrix effects in complex cereal samples.

Future Trends and Potential Applications

Emerging developments may include automation and miniaturization of QuEChERS workflows, application to additional packaging migrants and contaminants, integration with high-resolution mass spectrometry, and novel sorbent chemistries for improved cleanup efficiency.

Conclusion

The modified QuEChERS sample preparation combined with GC-MS on a TraceGOLD TG-17MS column provides a rapid, reliable, and solvent-saving method for monitoring benzophenone and 4-hydroxybenzophenone in breakfast cereal, delivering high recoveries and precision in line with regulatory requirements.

References

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(2):412.
3. European Committee for Standardization. EN15662:2008. Foods of plant origin – Determination of pesticide residues by GC-MS and/or LC-MS/MS following acetonitrile extraction and dispersive SPE.