Analysis of Water-Soluble Vitamins and Caffeine in Beverage and Multivitamin Products by Arc HPLC System With PDA Detection

Significance of the Topic

Regular intake of water-soluble vitamins and caffeine through dietary supplements and fortified beverages plays a vital role in supporting human health and meeting recommended daily nutrient levels. Analytical methods that rapidly verify vitamin content are essential for manufacturers to ensure label accuracy, comply with regulatory standards, and protect consumers from under- or over-dosing.

Objectives and Study Overview

This study presents a streamlined high-performance liquid chromatography (HPLC) method capable of separating and quantifying ten water-soluble vitamins along with caffeine in multivitamin tablets and beverage matrices. The primary aim was to develop a robust, fast, and reliable workflow to meet routine quality control demands in the food and supplement industries.

Methodology and Instrumentation

The analytical protocol utilizes reversed-phase gradient elution on an XSelect HSS T3 XP column, operated at pH 3.0 and 30 °C. Key instrument components include:

• Arc HPLC System
• 2998 Photodiode Array Detector monitoring at 205 nm and 254 nm
• Empower 3 Chromatography Data Software
• XSelect HSS T3 XP Column (4.6 mm × 150 mm, 2.5 µm)
• 0.2 µm PVDF syringe filters and standard screw-neck vials

Sample preparation involves aqueous extraction for most vitamins, followed by alkaline extraction for folic acid, riboflavin, and biotin. Beverage samples require simple filtration.

Main Results and Discussion

Method performance was assessed in terms of linearity, precision, limits of detection and quantification, robustness, and column longevity:

• Separation achieved in under 16 minutes with resolution of all target analytes
• Calibration linear over 0.4–100 µg/mL (R2 > 0.999 for most compounds)
• Limits of quantification around 0.4 µg/mL, with signal-to-noise ratios meeting 10:1 criteria
• Retention time and peak area repeatability below 2 % relative standard deviation (RSD)
• Stable performance across minor temperature (28 – 32 °C) and pH (2.8 – 3.2) variations
• Column pressure increased by only ~200 psi after 1 000 injections, demonstrating extended lifetime

Applied to commercial adult and children’s tablets and various fortified beverages, the method accurately quantified vitamins B1, B2, B3, B5, B6, B7, B9, C, and caffeine, supporting label claim verification.

Benefits and Practical Applications

The proposed HPLC-PDA approach offers:

• Rapid throughput for routine quality control of supplements and drinks
• High sensitivity to detect low-level vitamins without extensive sample dilution
• Reduced method complexity by consolidating multiple analytes into a single run
• Assured compliance with FDA and EU fortification regulations

Future Trends and Potential Applications

As consumer demand grows for fortified products, analytical platforms may evolve to include higher-throughput UHPLC systems, automated sample preparation, and multi-detector configurations to expand analyte scope. Real-time monitoring and on-line sample cleanup are promising trends for in-process quality assurance.

Conclusion

The described Arc HPLC-PDA method with XSelect HSS T3 XP column delivers fast, precise, and robust quantification of water-soluble vitamins and caffeine in tablets and beverages. Its reliability and ease of use make it an excellent tool for manufacturers seeking efficient nutrient analysis and regulatory compliance.

References

1. European Regulation (EC) No. 1925/2006 on the addition of vitamins and minerals to foods
2. U.S. Code of Federal Regulations Title 21 Part 101 (Food Labeling) and Part 104 (Nutritional Quality Guidelines)
3. Benvenuti M, Riches E The rapid analysis of 10 water-soluble vitamins, caffeine, and common food dyes using UPLC-UV 2009
4. Yang J, Rainville P Analysis of soft drink additives without aspartame degradant interference using Arc HPLC-PDA 2021