High-Resolution and High-Speed Simultaneous Analysis of Regulated UV-Adsorbents in Cosmetics using SPP Column

Importance of the Topic

Ultraviolet (UV) absorbers are widely used in cosmetics to protect the skin from UV radiation.
Regulatory agencies impose strict limits on the types and concentrations of these ingredients, making reliable and efficient analytical methods essential for quality control and compliance in the cosmetics industry.

Objectives and Study Overview

This study demonstrates a high-resolution, high-speed simultaneous analysis of 23 regulated UV absorbers in cosmetic products.
Using a modern low-pressure gradient LC system and a core–shell particle column, the goal was to shorten analysis time while maintaining accuracy and precision.

Methodology

Sample Preparation:

• Standards: 23 UV absorbers at 1–100 mg/L range for calibration and reproducibility studies.
• Commercial sample: 100 mg of cream extracted with tetrahydrofuran, ultrasonic treatment, centrifugation, and dilution with acetonitrile.

Chromatographic Conditions:

• Column: Shim-pack Velox C18, 100 mm × 3.0 mm, 2.7 μm core–shell.
• Mobile Phases: A) 0.1% formic acid in water, B) acetonitrile, C) methanol.
• Gradient: 0–20 min low-pressure program from high aqueous to high organic content.
• Flow Rate: 1.0 mL/min; Column Temperature: 60 °C; Injection Volume: 1 µL.
• Detection: Dual-wavelength UV at 310 nm and 355 nm.

Used Instrumentation

• Nexera LC system (Shimadzu)
• Shim-pack Velox C18 core–shell column
• UV detector with dual-wavelength capability

Main Results and Discussion

The mixed standard solution of 23 UV absorbers was separated within 20 minutes with resolution adequate for all peaks, including challenging late-eluting compounds.
Linearity was excellent (R2 ≥ 0.999) across the 1–100 mg/L range.
Reproducibility studies (n=6) showed retention time RSD ≤ 0.41% and peak area RSD ≤ 1.98% for all compounds.
Analysis of a cosmetic cream confirmed that all detected UV absorbers were present below the regulatory limits specified by Japanese law.

Benefits and Practical Applications

• High throughput: simultaneous quantitation of 23 analytes in a single 20-minute run accelerates routine QC workflows.
• Low system pressure despite high speed improves column lifetimes and reduces maintenance.
• Versatile detection at two wavelengths enhances sensitivity for a broad range of UV absorbers.
• Suitable for compliance testing in various regulatory frameworks and supporting import/export controls.

Future Trends and Potential Applications

• Integration with mass spectrometric detection for enhanced selectivity and lower detection limits.
• Automation of sample preparation to further increase throughput and reproducibility.
• Expansion to emerging UV filters and photostabilizers in cosmetic formulations.
• Real-time monitoring and on-line process control in cosmetic manufacturing lines.

Conclusion

This application note showcases a robust, fast, and reliable HPLC method for the simultaneous analysis of 23 regulated UV absorbers in cosmetics using a core–shell column and low-pressure gradient.
The procedure offers excellent linearity, reproducibility, and regulatory compliance within a drastically reduced analysis time, benefiting quality control laboratories and manufacturers.