Determination of aniline derivatives in oils related to the toxic oil syndrome by atmospheric pressure ionization-tandem mass spectrometry

In 1981, an unknown disease appeared in Spain, the Spanish Toxic Oil Syndro me. Nowadays and despite all efforts, the etiological agent is still unknow n. Early studies showed a link between this illness and the consumption of denatured rapeseed oil fraudulently processed and marketed as edible oil. T wo families of aniline derivatives present in these oils (fatty acid anilid es and acylated phenyl amino propanediol derivatives or PAPs) were found to be good chemical markers of toxic oils. In this work, a new method has bee n developed to analyze these aniline derivatives in oil samples by HPLC-MS and HPLC-MS/MS with an API source. For their quantification, three differen t internal standards were used, one for anilides and two for PAPs. Quantifi cation limits were 8 ppm for anilides and 0.2 ppm for PAPs. Anilides and PA Ps were found in marker-positive samples at levels up to 50 000 and 330 ppm , respectively. The relative abundance of the different fatty acid anilides and PAPs correlates with the fatty acid composition of the oils. More than 2600 different samples were analyzed by this method in the most exhaustive screening of suspected toxic oils carried out to date.