Determination of bisphenol A, nonylphenol and triclosan in materials and extracts by TLC combined with a digital colorimetry

Abstract

It was developed the method for determination of toxicants (bisphenol A, triclosan, and nonylphenol) which can migrate from the household and construction materials to liquid phase. This method is carried out using normal phase TLC combined with a digital colorimetry. Colorimetric parameters of the chromatographic spots presented as polar diagrams, they were used as an integral indicator. As the analytical signal used the retention parameter Rf, perimeter and area of this diagrams and the criterion of similarity of diagrams (the factor of proximity of vector arrays). The low-temperature liquid-liquid extraction by a mixture of acetonitrile – ethyl acetate (85:15) and acetonitrile - IPA – ethyl acetate (80: 5: 15) which cooled to temperature of -10°C used for preparing of samples.
For TLC of phenols the plates of Sorbfil were used as the stationary phase. The mixture of chloroform - ethyl acetate - acetic acid (50: 50: 1) was used as mobile phase. Chromatographic spots were colored with chromophoric agents: the mixture of ferrum (III) chloride - potassium ferricyanide (blue spots) and the solution of KMnO4 in diluted CH3COOH (yellow spots on the pink background). Improved methods for determining of phenolic toxicants by TLC combined with a digital colorimetry has satisfactory metrological characteristics and the increase of information through the use of digital technologies.