Headspace sorptive extraction coupled to gas chromatography-mass spectrometry for the determination of benzene, toluene, ethylbenzene and xylenes in finger paints

Abstract

The presence of benzene, toluene, ethylbenzene and xylenes (BTEX) in dyes, paints and pigments is not still regulated but might be an indicator of contamination due to the well-known health risk of these compounds. An analytical procedure based on headspace sorptive extraction using a polydimethylsiloxane stir bar, was developed for the gas chromatographic determination of BTEX in finger paint samples. Univariate and multivariate designs were used to optimize experimental parameters, including equilibrium time, desorption time, saline effect and sample mass. Thirty minutes were necessary to absorb the analytes in the polydimethylsiloxane stir bar followed by a 5 min thermal desorption step. Limits of quantification of between 0.036 and 0.12 ng g−1 depending on the compound, were obtained. BTEX were found in the finger paint samples at levels between 0.14 and 12 ng g−1.