Active Ingredients in Sunscreen Lotion by Normal-Phase Chromatography on a Thermo Scientific ™ Acclaim™ Mixed-Mode WAX-1 Column

Význam tématu

Sunscreen lotions contain complex oil bases that pose challenges for reversed-phase analysis. Normal-phase chromatography enables the oils to elute in or near the void volume while retaining and resolving the active sunscreen agents.

Cíle a přehled studie / článku

This study evaluates the performance of the Thermo Scientific™ Acclaim™ Mixed-Mode WAX-1 column in separating two common UV filters, octyl salicylate and octyl methoxycinnamate, from a sunscreen lotion matrix using normal-phase conditions.

Použitá instrumentace

• Column: Acclaim Mixed-Mode WAX-1, 5 µm, 4.6 × 150 mm
• Pump: Dionex Summit P680A DGP
• Mobile Phase: heptane : dichloromethane (99 : 1 v/v)
• Flow Rate: 1.0 mL/min
• Temperature: 30 °C (TCC-100 thermostat)
• Injection: ASI-100 sampler, 10 µL
• Detector: UVD-340U, UV detection at 305 nm

Použitá metodika

The column was conditioned sequentially with 0.5% acetic acid, methanol, and the mobile phase. Sample preparation involved dispersing 200 mg of sunscreen in 10 mL heptane and 2 mL of 10% Na2SO4, followed by sonication, vigorous shaking, phase separation, and a 10× dilution of the heptane extract.

Hlavní výsledky a diskuse

• Baseline separation of octyl salicylate (44 µg/mL) and octyl methoxycinnamate (154 µg/mL) was achieved within 7 minutes.
• Oily components eluted in the void, simplifying the chromatogram and reducing interference.
• The mixed-mode WAX-1 column combined normal-phase retention of polar UV filters with rapid elution of nonpolar matrix components.

Přínosy a praktické využití metody

• Rapid and robust quantification of UV filters in oily cosmetic formulations.
• Minimal sample preparation due to effective oil removal by void elution.
• Suitable for routine quality control in sunscreen manufacturing.

Budoucí trendy a možnosti využití

• Extension to a broader range of UV-active compounds.
• Coupling with mass spectrometry for enhanced sensitivity and specificity.
• Development of automated inline sample cleanup for high-throughput analysis.
• Advancement of mixed-mode stationary phases to tailor selectivity.

Závěr

The Acclaim Mixed-Mode WAX-1 column offers an effective normal-phase solution for analyzing sunscreen lotions, delivering fast separation, clear resolution of active ingredients, and simplified sample preparation for quality control applications.