A novel fast and simple quantication method for vitamins, complements and contaminants in milk infant formulas by LC-MS/MS

Significance of Topic

The accurate quantification of vitamins, essential nutrients and potential contaminants in infant milk formulas is critical to ensure infant health, regulatory compliance and product quality. A streamlined method that addresses the diverse chemical properties of water- and fat-soluble compounds in a single workflow enhances laboratory efficiency and reduces analysis time.

Objectives and Study Overview

This study aimed to develop and validate a rapid, robust LC-MS/MS platform capable of simultaneously quantifying multiple vitamins, nutritional supplements and trace contaminants in commercial infant formula. The approach unifies sample preparation, chromatographic separation and mass spectrometric detection into a cohesive method suitable for quality control laboratories.

Methodology and Instrumentation

Sample Preparation:

• Water-Soluble Fraction: Extraction with acidified methanol, followed by dilution and centrifugation.
• Fat-Soluble Fraction: Solid-phase extraction (SPE) on Biotage ABN cartridges with ethanol and water washes.

Chromatography and Detection:

• UHPLC System: Shimadzu Nexera X2 with reverse-phase column (150 × 2.1 mm, 3 µm) at 60 °C.
• Mobile Phases: Water and acetonitrile containing formic acid and ammonium formate, 400 µL/min flow.
• Mass Spectrometer: Shimadzu LCMS-8050 with heated electrospray ionization (HESI), polarity switching (5 ms), capable of >30 points per peak and 555 MRM transitions per second.

Main Results and Discussion

Linearity and Sensitivity:

• All target analytes exhibited linear response over expected concentration ranges (µg/100 g) with correlation coefficients (r²) above 0.98.
• Limits of quantification (LLOQ) achieved signal-to-noise ratios >10 for all compounds.

Extraction Recoveries:

• Fat-soluble vitamins A, D3, E and K1 displayed recoveries between 83% and 107% (±3–8%).
• Water-soluble vitamins B1–B12, C, biotin, taurine, choline, inositol, L-carnitine, melamine, aflatoxin M1, chlorate and perchlorate showed recoveries of 79% to 112% (±1–9%).

Chromatographic Performance:
Total run time of 14 minutes enabled separation of over twenty analytes with baseline resolution and high throughput.

Benefits and Practical Applications

The unified LC-MS/MS workflow offers:

• Reduced sample handling and analysis time by consolidating two extraction protocols with a single chromatographic run.
• High specificity and sensitivity for regulatory monitoring of nutrient fortification and contaminant limits in infant nutrition products.
• Scalability for routine quality assurance in industrial and contract laboratories.

Future Trends and Opportunities

Emerging directions include:

• Adoption of high-resolution mass spectrometry to expand analyte scope and improve structural confirmation.
• Increased automation of sample preparation using online SPE or robotic platforms.
• Use of greener solvents and miniaturized extraction techniques to reduce environmental impact.
• Real-time data processing with AI-driven analytics for rapid decision-making in production environments.

Conclusion

The presented LC-MS/MS method delivers a fast, reliable solution for comprehensive quantification of vitamins, supplements and contaminants in infant milk formulas. Its validated performance demonstrates suitability for regulatory compliance and routine quality control, combining high throughput with robust analytical figures of merit.

References

• Legoupil T., Jaffuel A., Huteau A. “A novel fast and simple quantification method for vitamins, complements and contaminants in milk infant formulas by LC-MS/MS,” ASMS 2017, MP-192.