Collaborative peer validation of a harmonized SPME-GC-MS method for analysis of selected volatile compounds in virgin olive oils

The requirement for developing an instrumental method for analysis of volatile compounds responsible for the aroma that supports the work of the sensory panel test of virgin olive oils is a matter of great importance. In this paper, five laboratories participated in a collaborative study within the EU H2020 OLEUM project to develop a peer interlaboratory study of a harmonized SPME-GC-MS method for determination of volatile compounds in virgin olive oil responsible for positive attributes (e.g. fruity) and the main sensory defects. Linearity (R-2 > 0.94) and repeatability (mean relative standard deviation, RSD% = 7.60%) were satisfactory. Reproducibility results were uneven depending on the compound. The lowest RSD% values were found for (Z)-3-hexenyl acetate (19.19%), 1-hexanol (13.26%), and acetic acid (17.47%). The limits of quantification were <0.07 mg/kg for all compounds except for (E)-2-decenal and pentanoic acid. The study of different quantification methods revealed that the correction of the calibration curves using the internal standard led to a slightly worse repeatability, but better accuracy and reproducibility. The results obtained by five laboratories are preparatory towards a trial proper validation study, already planned in OLEUM project, involving external labs participating on a voluntary basis.