Solid phase micro extraction arrow optimization for the screening of volatiles compounds in recycled plastics in GC/MS.

The aim of this work is to develop and optimize a non-targeted screening (NTS) method based on Arrow SPME for the characterization of volatile and semi-volatile compounds in recycled polyethylene terephthalate (PET) and polyolefins (POs). Both, solid materials and migration extracts obtained with food simulants (ethanol 10 %, ethanol 95 %, and acetic acid 3 %) were studied. The method development considered both headspace and direct immersion extraction modes to assess their relative performance and applicability depending on the sample type. To achieve robust optimization, a RSM based on CCD was employed, allowing the evaluation of the effects and interactions of key variables such as extraction time, temperature, and sample amount. Separate designs were constructed for each sample type, acknowledging their distinct behaviour and matrix effects. A mixture of 15 selected Food Contact Materials (FCM) analytes showed that SPME Arrow improved sensitivity, with response factors 7-14 % higher than traditional SPME. It also demonstrated superior linearity (R² > 0.990 for all analytes) and lower variability, whereas conventional SPME showed acceptable linearity for only a limited number of compounds.