Determination of Phthalates in vegetables by GPC–GCMS

Significance of the topic

Phthalates (PAEs) are widely used plasticizers with potential endocrine-disrupting effects. Vegetables may accumulate PAEs via environmental contamination or packaging materials. Reliable analytical methods are essential for food safety assessment and regulatory control.

Objectives and study overview

This study aims to develop a rapid, sensitive, and reproducible method for simultaneous determination of 22 phthalates in various vegetable matrices using gel permeation chromatography coupled to gas chromatography-mass spectrometry (GPC–GCMS).

Methodology and instrumentation

Vegetable samples were homogenized, extracted with water, and partitioned into hexane. The extract was cleaned by GPC on a Shodex CLNpak EV-200 column using acetone/cyclohexane (3:7, v/v).

• GPC: Shodex CLNpak EV-200 (2.1×150 mm); mobile phase acetone/cyclohexane 3/7; flow rate 0.1 mL/min; 40 °C; injection volume 20 µL.
• GC–MS: WondaCap WAX column (25 m×0.25 mm×0.25 µm); oven program 82 °C (5 min) → 150 °C at 8 °C/min → 240 °C at 25 °C/min; injection temperature 120 °C → ramp to 280 °C; SIM acquisition mode with characteristic fragment ions.

Instrumentation Used

• Shimadzu GPC–GCMS system
• Shodex CLNpak EV-200 GPC column
• WondaCap WAX GC column

Main results and discussion

Calibration exhibited excellent linearity (R2 > 0.999) over 0.005–1.0 µg/mL. Repeatability RSD was < 5 % at 0.05 µg/mL. Method detection limits were < 3 µg/kg. Recoveries in lettuce, canola, and celery spiked at 0.1–0.4 mg/kg ranged from 60 % to 130 %.
Chromatograms showed distinct separation of all 22 PAEs with clear retention time resolution. SIM mode enabled selective and sensitive quantification, minimizing matrix interferences.

Benefits and practical applications

• Allows rapid screening of multiple phthalates in complex vegetable samples.
• Combines effective cleanup with high-sensitivity detection for QA/QC laboratories.
• Streamlined sample preparation reduces analysis time and solvent usage.

Future trends and opportunities

Further developments may include automation of extraction and GPC cleanup, expanding the scope to emerging plasticizers, and integration with high-resolution mass spectrometry for improved compound identification. Adoption in regulatory frameworks will strengthen food safety monitoring.

Conclusion

The developed GPC–GCMS method provides a sensitive, user-friendly, and robust platform for routine determination of 22 phthalates in vegetable matrices, supporting regulatory compliance and food safety initiatives.

References

• X. Zhang; G. Yang; J. Fan; T. Huang. Determination of Phthalates in vegetables by GPC–GCMS. Shimadzu CO. LTD application note WP213, ASMS 2016.