Determination of Phthalates in Beverage by UFLC- Triple Quadrupole Mass Spectrometry

Importance of the Topic

Phthalates are synthetic plasticizers widely used to improve the flexibility and durability of polymer products. Their potential toxicity and ability to migrate into food and beverages make reliable detection methods critical for ensuring public health and regulatory compliance.

Aim and Overview of the Study

This study aimed to develop and validate a rapid, sensitive, and precise analytical method for the quantification of 16 phthalate esters in beverage matrices using ultra-fast liquid chromatography coupled to a triple quadrupole mass spectrometer. The method targets routine quality control and safety monitoring in the food and beverage industry.

Used Methodology and Instrumentation

Sample Preparation:

• Aliquot 5.0 mL of beverage sample.
• Add 2.0 mL n-hexane, shake 2 min, allow phase separation.
• Collect 1.0 mL of organic layer, evaporate under nitrogen.
• Reconstitute to 1.0 mL with 50 % methanol aqueous solution; inject 10 µL.

Chromatographic Conditions:

• Column: Shim-pack XR-ODS III (2.0 mm × 150 mm, 2.2 µm).
• Mobile phases: A) 5 mM ammonium acetate aqueous; B) methanol.
• Gradient elution 0.01–10.00 min: Pump B from 75 % to 100 % and back.
• Flow rate 0.4 mL/min; column temperature 45 °C.

Mass Spectrometry:

• Ionization: ESI positive mode, 4.5 kV.
• Source gases: nitrogen nebulizing (3.0 L/min), drying (15 L/min); collision gas: argon.
• Temperatures: DL 250 °C, block 450 °C.
• Acquisition: multiple reaction monitoring (MRM), dwell 10 ms.

Calibration and Standards:

• Multi-phthalate standards prepared at 10–500 µg/L using internal standard D4-DEHP.
• Calibration curves constructed by plotting area ratio vs. concentration; correlation coefficients ≥ 0.999.

Main Results and Discussion

Linearity and Sensitivity:

• All 16 phthalates exhibited excellent linearity (r ≥ 0.9994) over 10–500 µg/L.
• Limits of quantification ranged from 0.09 to 67.8 µg/L; LODs from 0.03 to 22.4 µg/L.

Precision:

• Sixfold injection of standards at 20, 50, and 100 µg/L showed retention time RSDs ≤ 1.04 % and area RSDs ≤ 4.15 %.

Recovery and Real Samples:

• Spike recovery for DEHP in green tea matrix was 90.4 % at 50 µg/L spiking level.
• Analysis of four commercial beverages (green tea, sports drink, guava juice, milk tea) detected DEHP at 0.004–0.785 mg/L.

Benefits and Practical Applications

The developed UFLC-MS/MS method offers rapid analysis (10 min per run), high throughput, and robust quantification suitable for routine monitoring in food safety laboratories. Its low detection limits and strong precision make it ideal for regulatory compliance and contamination screening.

Future Trends and Potential Uses

Advances in ultra-high-performance chromatography and high-resolution mass spectrometry may further reduce analysis time and enhance selectivity for emerging phthalate analogues. Coupling automated sample preparation and data-processing workflows can streamline large-scale surveys of consumer products and environmental samples.

Conclusion

A validated UFLC-MS/MS protocol using Shimadzu LC-30A and LCMS-8030 efficiently quantifies 16 phthalates in beverages with excellent sensitivity, accuracy, and precision. The approach is well suited for routine food safety testing and toxicological assessments.

Used Instrumentation

• Shimadzu UFLC system: LC-30AD pumps, DGU-20A5 degasser, SIL-30AC autosampler, CTO-30A column oven, CBM-20A controller.
• Shimadzu triple quadrupole mass spectrometer LCMS-8030 with LabSolutions Ver. 5.41.

References

No references provided.