Development and Validation of a Headspace Gas Chromatography–Mass Spectrometry Method for the Identification and Quantification of Glycol Ethers in Cosmetic Cream Formulations

An analytical method was developed and validated for the simultaneous detection of four glycol ethers in cosmetic creams using headspace gas chromatography coupled with mass spectrometry (HS-GC–MS). Samples were extracted with ethanol and then subjected to vortexing and ultrasonic treatment prior to analysis. The analytes showed good linearity within the concentration range of 25–200 µg/mL, with determination coefficients (R²) exceeding 0.995. Limits of detection (LOD) and quantification (LOQ) were determined for each compound. For ethylene glycol dimehyl ether (EGDME), LOD and LOQ were 1.39 and 4.00 µg/mL, respectively. For diethylene glycol monoethyl ether (DEGEE), values were 3.70 and 12.34 µg/mL. Triethylene glycol dimethyl ether (TEGDME) showed LOD and LOQ of 1.61 and 5.38 µg/mL. For phenoxyethanol (EGPhE), these limits were 4.79 and 15.95 µg/mL. Mean recovery rates ranged from 96.72% to 100.40%, and relative standard deviations (RSDs) remained below 15% across all validation procedures. The average method recovery ranged between 100.34% and 102.09%. The validation parameters, including specificity, linearity, precision, trueness, and accuracy, were found to be satisfactory.