Simultaneous determination of multiclass preservatives including isothiazolinones and benzophenone‐type UV filters in household and personal care products by micellar electrokinetic chromatography

In this work, a simple and reliable micellar electrokinetic chromatography method for the separation and quantification of 14 preservatives, including isothiazolinones, and two benzophenone‐type UV filters in household, cosmetic and personal care products was developed. The selected priority compounds are widely used as ingredients in many personal care products, and are included in the European Regulation concerning cosmetic products. The electrophoretic separation parameters were optimized by means of a modified chromatographic response function in combination with an experimental design, namely a central composite design. After optimization of experimental conditions, the BGE selected for the separation of the targets consisted of 60 mM SDS, 18 mM sodium tetraborate, pH 9.4 and 10% v/v methanol. The MEKC method was checked in terms of linearity, LODs and quantification, repeatability, intermediate precision, and accuracy, providing appropriate values (i.e. R² ≥ 0.992, repeatability RSD values ?9%, and accuracy 90–115%). Applicability of the validated method was successfully assessed by quantifying preservatives and UV filters in commercial consumer products.