Abstract：Objective To develop an oil based headspace technique coupled with gas chromatography-mass spectrometry for determination of formaldehyde in cosmetics. Methods N, N-dimethylformamide was used as the sample dispersant after removing formaldehyde and purification, and headspace-gas chromatography-mass spectrometry was employed to detect formaldehyde in cosmetics. Results In this method, the chromatographic conditions, headspace conditions and dispersion solvents of the samples were optimized. The results displayed that the linearity of formaldehyde was good in the range of 1-400 mg/L, and the correlation coefficient (r) was 0.9993. The recoveries of formaldehyde at low-, medium- and high-concentration levels in different dosage forms of cosmetics ranged from 90.1% to 105.2%, with a relative standard deviation of 1.8%-3.7%. The detection limit was 5 mg/kg, and the quantitative limit 10 mg/kg. Totally eight batches of cosmetic samples with 6 different types sold in the markets were determined, and formaldehyde was detected in 6 samples, with the content ranging from 15.1 mg/kg to 49.7 mg/kg. Conclusion In this method, N, N-dimethylformamide was used as extractant and good dispersion effect for various matrix cosmetics samples was achieved, because it had strong dissolving ability for both fat-soluble and water-soluble compounds. Furthermore, it had high boiling point, and the method effectively reduced matrix interference by controlling the headspace temperature. The actual measurement of samples shows that the method has the advantages of simple operation, strong anti-interference ability, high sensitivity, accuracy and good reliability.
2023, Vol. 30 
