“…In a recent study, Koster et al indicated that when MOH contamination is low, current methodologies cannot reliably conclude whether or not the sample is contaminated (Koster et al, 2020). Therefore, it is necessary to apply additional confirmatory techniques, such as two-dimensional gas chromatography (GCxGC), mass spectrometry, and the identification of chemical markers (Jaén, Domeño, Alfaro, & Nerín, 2021;Moret et al, 2013;Spack et al, 2017).…”