Solvent extraction and gas chromatography–mass spectrometric determination of probable carcinogen 1,4-dioxane in cosmetic products

In the present work, a method based on solvent extraction and gas chromatography–mass spectrometry (GC-MS) has been validated for the determination of 1,4-dioxane in cosmetics. Various solvents including ethyl acetate, hexane, methanol, dichloromethane and acetone have been used for the extraction of 1,4-dioxane, among them the ethyl acetate was found to be the most efficient extracting solvent. This method has offered excellent quality parameters for instance linearity (R2 > 0.9991), limit of detection (LOD, 0.00065-0.00091 µg/mL), limit of quantification (LOQ, 0.00217–0.00304 µg/mL) and, precision intra-day (1.65–2.60%, n = 5) and inter-day (0.16–0.32%, n = 5) in terms of relative standard deviation (RSD%). A total of thirty-nine cosmetic samples of different brands and origin have been studied. Among them, the 1,4-dioxane was found in twenty-three samples (FB1-FB7, MC1-MC4, MC6-MC8, HS3, HS5, BL1-BL3, BL5 and PLD1-PLD3) at the levels between 0.15 µg/mL and 9.92 µg/mL, whereas in sixteen samples (MC5, HS1, HS2, SG1-SG5, BL4 and HP1- HP6) was found to be not detected. The recovery values were achieved between 93% and 99% in both low and high level of spiked samples. In comparison to the traditional analytical techniques, the proposed method was found to be very sensitive and cost-effective for the routine analysis of 1,4-dioxane at low concentration in cosmetics.