Simultaneous determination of 38 limited colorants in cosmetics by high performance liquid chromatography

Abstract

A method has been established for the simultaneous determination of 38 limited colorants in cosmetics by high performance liquid chromatography (HPLC). The samples were extracted by ultrasonic with tetrahydrofuran, methanol, ammonium acetate solution as extraction solvents. After centrifugation, nitrogen blow and redissolved in turn, the extracts were separated on an Agilent zorbax SB-Aq column (150 mm x 3.0 mm, 3.5 µm) using a gradient elution program with acetonitrile and 30 mmol/L ammonium acetate containing 0.075% (v/v) formic acid as mobile phases. The detection wavelengths were set at 254, 416, 484, 514, 590 and 620 nm. The linear ranges of the 38 target compounds were all in the range of 1 to 10 mg/L with correlation coefficients more than 0.999. The limits of quantification (LOQs) for the 38 colorants were in the range of 5-50 µg/g. The average recoveries at two spiked levels ranged from 93.2% to 107.6% with the relative standard deviations (RSDs) less than 10% (n = 6). This method is accurate, simple, sensitive and reliable, and can be used for the analysis of the 38 limited colorants in cosmetics.