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

Significance of the Topic

Ultraviolet light absorbers are widely used in cosmetic formulations to protect skin from UV damage. Regulatory limits vary by region, making reliable quantitation essential for quality control and compliance in import/export. High-throughput HPLC methods that deliver fast, accurate results support industry demands for efficient screening of multiple UV-absorbers.

Objectives and Study Overview

This study aimed to develop a rapid, high-resolution liquid chromatography method for simultaneous analysis of 23 regulated UV-absorbers in cosmetics. It extends previous work by including additional compounds regulated by EU and Japanese standards, demonstrating low-pressure operation and shortened run times while maintaining separation efficiency.

Methodology and Instrumentation

A core-shell C18 column and a low-pressure gradient were employed to reduce backpressure and accelerate analysis. Key experimental parameters:

• LC system: Nexera high-performance liquid chromatograph
• Column: Shim-pack Velox C18, 100 mm × 3.0 mm I.D., 2.7 µm superficially porous particles
• Mobile phases: A) 0.1 % formic acid in water; B) acetonitrile; C) methanol
• Flow rate: 1 mL/min; Column temperature: 60 °C; Injection volume: 1 µL
• Detection wavelengths: 310 nm and 355 nm
• Gradient program: 0–2 min (90 % A→60 % A), 2–4 min (60 % A→25 % A), 4–14 min (25 % A→0 % A), hold at organic, then re-equilibration

Main Results and Discussion

Standard mixtures containing 23 UV-absorbers at 100 mg/L each were baseline separated within 20 minutes. All analytes exhibited excellent linearity (R2 ≥ 0.999) across 1–100 mg/L. Reproducibility was high, with retention time RSD ≤ 0.41 % and peak area RSD ≤ 1.98 % over six injections. Application to a cosmetic cream involved simple THF extraction, centrifugation, dilution with acetonitrile, and filtration; all detected levels were below regulatory maxima.

Benefits and Practical Applications

The method offers:

• Rapid throughput: 23 analytes in under 20 minutes
• Low operating pressure (< 30 MPa) for extended column life
• High precision and quantitative accuracy for QC and regulatory compliance
• Simple sample preparation suitable for routine laboratory workflows

Future Trends and Potential Applications

Advances may include coupling with mass spectrometric detection for enhanced specificity, automation of sample extraction, further miniaturization via UHPLC approaches, and expansion to cover emerging UV-filter formulations. Integration into high-throughput screening platforms could support broader safety assessments and regulatory monitoring.

Conclusion

A low-pressure, core-shell LC method was established for efficient simultaneous analysis of 23 UV-absorbers in cosmetics. It achieves fast separation, robust quantitation, and compliance with regulatory standards, making it a valuable tool for industrial QC and regulatory testing.