Consumable-free Comprehensive Three-Dimensional Gas Chromatography and PARAFAC for Determination of Allergens in Perfumes

A new consumable-free three-dimensional comprehensive gas chromatography (GC(3)-FID) was designed with modulators already known to comprehensive two-dimensional gas chromatography (GC x GC) users to showcase the opportunity of implementing GC(3) systems. A hybrid interface composed of a thermal desorption modulator and a fast forward-flush differential flow modulator was used with modulation periods of 6 s and 300 ms, respectively. The determination of allergens in perfumes associated with chemometric tools, namely, parallel factor analysis (PARAFAC) was accomplished to demonstrate the validity of the proposed system. Evaluated allergens included already regulated ones in Brazil and Europe, such as geraniol and menthol, as well as potential allergens recommended in a 2011 opinion reported by the European Scientific Committee on Consumer Safety. Limits of detection were found to be suitable for current regulations, under 0.001% or 10 mu L L-1 for leave-on products. Considerations on the required acquisition rates, the limitations imposed by current modulator technology, the modulation periods used, and how they affect all three dimensions are thoroughly discussed. A GC(3) coupled with mass spectrometry (GC(3)-MS) approach is also covered, as well as a comparison of the signal resolution/deconvolution with the increase of data dimensionality. Lastly, the union of GC(3) and chemometric tools allowed for a solution that may be used for both qualitative and quantitative analyses.