Optimization of parameters for the analysis of aromatic amines in finger-paints

A study for the optimisation of the supercritical fluid extraction (SFE) of some aromatic amines (4-chloro-o-toluidine. 2-naphthylamine, 4-aminobiyhen yl and benzidine) in finger-paints was conducted. The influence of differen t variables related to the technique on recoveries was investigated. The an alytes were subsequently analysed by gas chromatography after SFE. The stud y allowed the estimation of four main factors (temperature, pressure, stati c time and volume of modifier) on recoveries by the use of a two-level fact or design, where most significant parameters as well as second- and third-o rder interactions were identified. Other factors, such as type and volume o f modifier and time of contact between the spiker solution and the sample p rior to extraction, were also studied. The influence of matrix on extractio n recovery was also evaluated by applying the method to different finger-pa ints, and recoveries were similar or even higher in some cases. The drying process of samples was also studied, while classical drying in an oven and microwaves were compared, with similar efficiencies in both methods. The me thod was validated by extracting the aromatic amines from some commercial f inger-paints. (C) 2000 Elsevier Science B.V. All rights reserved.