Determination of common food and beverage additives by UHPLC-UV using a mixed mode WAX column

Importance of the Topic

Monitoring and quantifying additives in food and beverages are critical for ensuring quality, regulatory compliance and consumer safety. Ultra-high-performance liquid chromatography with UV detection (UHPLC-UV) offers a rapid, robust platform to separate a broad range of neutral and ionic compounds in complex matrices.

Goals and Study Overview

The study demonstrates the seamless transfer of an isocratic UHPLC-UV method for seven common carbonated beverage additives from a Thermo Scientific UltiMate 3000 system to a Vanquish Flex UHPLC system. The objective was to maintain separation performance and enhance reproducibility without the need for method redevelopment.

Methodology and Instrumentation

An Acclaim Mixed Mode WAX-1 column (150×4.6 mm, 5 μm) was employed with an isocratic mobile phase consisting of 120 mM potassium dihydrogen phosphate (pH 3.0) and acetonitrile (45:55 v/v) at a flow rate of 1.5 mL/min and column temperature of 30 °C. A 5 μL injection of a mixed standard containing caffeine, aspartame, sorbate, benzoate, citrate, acesulfame and saccharin was monitored at 210 nm.

Instrumentation Used

• UltiMate 3000 UHPLC: LPG-3400RS pump, WPS-3000RS autosampler, TCC-3000RS oven, DAD-3000RS detector
• Vanquish Flex UHPLC: Quaternary Pump F, Split Sampler FT, Column Compartment H, Diode Array Detector HL
• Supporting accessories: Thermo Scientific Virtuoso vial identification and LightPipe flow cell

Main Results and Discussion

Baseline separation of all seven additives was achieved in under eight minutes on both systems. Retention times averaged over nine injections were nearly identical, confirming method equivalence. The Vanquish Flex system showed at least a 50% reduction in peak area relative standard deviation (RSD) for most analytes, attributed to its proprietary SmartInject autosampler and advanced pump design. Citrate exhibited higher RSD on both platforms due to broader peak shape affecting integration precision.

Benefits and Practical Applications

• Seamless method transfer reduces downtime and validation costs
• Mixed Mode WAX-1 column effectively retains neutral and ionic additives that challenge traditional reversed-phase columns
• Enhanced reproducibility supports routine QA/QC in food and beverage laboratories

Future Trends and Potential Applications

Applying this workflow to diverse beverage matrices—such as juices, dairy drinks and functional beverages—can streamline regulatory compliance testing. Coupling with mass spectrometry may improve detection limits and structural confirmation. Advances in UHPLC automation and inline sample preparation promise higher throughput and reduced analyst intervention in large-scale testing environments.

Conclusion

The transfer of an isocratic UHPLC-UV method from the UltiMate 3000 to the Vanquish Flex system using an Acclaim Mixed Mode WAX-1 column was achieved without loss of chromatographic performance. The Vanquish Flex platform’s improved reproducibility highlights the value of modern pump and autosampler innovations for reliable additive analysis.