Headspace GC/MS Analysis of Residual Solvents in Dietary Supplements, Cosmetics, and Household Products Using Ethyl Lactate as a Dissolution Medium

Background: The static headspace technique is one of the most popular techniques for residual solvent analysis and dimethyl sulfoxide (DMSO) and N,N-dimethylformamide (DMF) are widely use as the dissolution media. Objective: This study aims to establish ethyl lactate (EL), a solvent with low toxicity and less environmental impact, as an alternative dissolution medium to DMSO and DMF for the static headspace analysis of toxic residual solvents in food, cosmetics, and similar complex organic matrices. Methods: Samples (a sample of dietary supplement and two samples each of cosmetics and household products) spiked with benzene, carbon tetrachloride, 1,2-dichloroethane, 1,1-dichloroethene, and 1,1,1-trichloroethane were dissolved in EL, DMSO, and DMF. Static headspace GC/MS and the standard addition method were used to detect and quantify the residual solvents. Results: The dissolution and dispersion of these samples, especially the ones which were water-insoluble, were better than those in DMSO and DMF. The recoveries, except that of benzene in an aerosol spray, in EL ranged from 77 to 110%. The relative SDs in EL ranged from 2.5 to 11% and were better or equivalent to those in DMSO and DMF. Conclusions: EL was suitable as the dissolution medium for such samples, which may contain large amounts of organic solvents or various ingredients, in static headspace GC/MS analysis of residual solvents.