Determination of synthetic colorants in cosmetic products by reversed-phase high-performance liquid chromatography coupled with diode-array detector

Abstract

This study aimed at developing and validating a reversed-phase (RP) high-performance liquid chromatography (HPLC) method, for simultaneous determination of five synthetic dyes called tartrazine (TRZ), sunset yellow (SY), allura red AC (AR), brilliant blue FCF (BB) and erythrosine B (EB) in cosmetic samples. The separation was performed by a C18 reverse phase analytical column (4.6 x 250 mm, 5 µm) at 30°C with gradient elution and the mobile phase contained 20 mM ammonium acetate buffer, acetonitrile and methanol. Flow was 1.0 mL/min. Detection wavelengths of diode array detector (DAD) were set at 420, 480, 510, 634 and 530 nm for TRZ, SY, AR, BB and EB, respectively. The dyes were analysed in 24 min. The limits of detection (LOD) was ≤ 0.18 µg/mL. The recovery was between 88.7 and 103.0%. Precision was ≤ .7.33 (RSD%) and accuracy was ≤ 3.0 (RE%). It was determined that 7 different cosmetic samples analyzed, consisting of soap, shower gel, eyeshadow, mouthwash, and lip pencil contained synthetic dyes at a concentration of 0.29 to 10.81 mg/g.