Formaldehyde analysis of seized cosmetic products by HS-GC-MS of methylal, ethoxymethoxymethane, and ethylal derivatives

Abstract Formaldehyde is a carcinogenic compound used as preservative in cosmetic products. In this study, a derivatization procedure using MeOH, EtOH and HCl (25:25:1), and incubation at 60ºC for 4 hours was optimized, and the derivatized products - methylal, ethoxymethoxymethane (EMM), and ethylal - were directly analyzed by headspace-gas chromatography-mass spectrometry (HS-GC-MS) to determine formaldehyde concentrations. The validated method provided good linearity of the standard curve, selectivity, recovery (89.6-106.6%), repeatability, and intermediate precision (RSD