Gas chromatographic analysis of free fatty acids and fatty acid salts extracted with neutral and acidified dichloromethane from office floor dust

A gas chromatographic method for estimation of fatty acid salts (FASs) in house dust has been developed. The difference between results for acidic and neutral extractions gives the FAS content of a sample. The method was designed to handle the inhomogeneity of the dust and to avoid false positive results due to low concentrations. The absolute recoveries of the model compounds octadecanoic acid and sodium octadecanoate were 91% and 77%, respectively. Problems with the internal standard and the inhomogeneity of floor dust, however, resulted in large variations and somewhat underestimated concentrations. The content of total FASs in eight samples of office floor dust were up to at least 0.5% in the fine particle fraction. (C) 1998 Elsevier Science B.V. All rights reserved.