XÂY DỰNG VÀ ÁP DỤNG PHƯƠNG PHÁP ĐỊNH LƯỢNG CHẤT BẢO QUẢN METHYLPARABEN TRONG CHẾ PHẨM GEL BẰNG SẮC KÝ LỎNG HIỆU NĂNG CAO (HPLC)

Abstract

Methylparaben is a commonly used preservative in cosmetics, pharmaceuticals, and food products; however, long-term exposure may pose health risks. This study aimed to develop and apply a quantification method for methylparaben in gel formulations using high-performance liquid chromatography (HPLC). The study samples included a self-prepared gel and six commercial gel products comprising both cosmetics and pharmaceuticals. Sample preparation was optimized using thermal extraction with ethanol as the solvent, followed by filtration and quantification via HPLC. The chromatographic conditions employed a reversed-phase C18 column (250 × 4,6 mm; 5 µm), a PDA detector at a detection wavelength of 255 nm, and a mobile phase consisting of acetonitrile and water (50:50, v/v), with a flow rate of 0,8 mL/min and column temperature maintained at 30°C. The method demonstrated good specificity, with a linear correlation coefficient (R²) of 0,99998, repeatability and intermediate precision with RSD% < 2,0%, and recovery rates within the range of 98,0% – 102,0%. The quantification range was 16 – 24 µg/mL, with a limit of detection (LOD) of 0,008 µg/mL and a limit of quantification (LOQ) of 0,026 µg/mL. The validated method met all required analytical criteria and was successfully applied to determine methylparaben content in commercial gel samples.