Resumen: Oligomers are potential migrants from polymers or biopolymers intended to food packaging and they have to be under control. In order to comply with European regulation 10/2011, their concentration in migration must be below 0.01 mu g g(-1). In this work, fabric phase sorptive extraction (FPSE) was explored as an effective method for extraction and pre-concentration of oligomers migrated from a blend PLA-polyester material. Both food simulant B (3% acetic acid) and juice, as real food, were used for migration experiments. The parameters of FPSE were optimized and the analysis was done by UHPLC-QTOF and UHPLC-QqQ. A total of 21 oligomers were identified, 9 of them coming from PLA and 12 oligomers from the polyester part. These oligomers were formed by adipic acid (AA), phthalic acid (PA) and/or butanediol (BD), ten were cyclic and 11 were linear molecules. Using the optimized FPSE procedure in 3% acetic acid as food simulant, it was possible to identify 3 new compounds that were not detected by direct injection of the simulant into UHPLC-QTOF. In addition, 2 extra compounds, cyclic PA-BD4-AA(3) and cyclic PA(2)-BD3-AA, were only identified in juice samples after FPSE extraction. Besides, in order to quantify the compounds identified, an isolation procedure for PLA oligomers was carried out. Two oligomers were isolated: cyclic (LA)(6) and linear HO-(LA)(4)-H, both with a purity higher than 90% (LA: lactic acid). The highest concentration value was found for the cyclic oligomer [AA-BD](2), that showed 22.63 mu g g(-1) in 3% acetic acid and 19.64 mu g g(-1) in juice. The concentration of the total amount of remaining oligomers was below 7.56 mu g g(-1) in 3% acetic acid as well as in juice. Idioma: Inglés DOI: 10.1016/j.talanta.2021.122603 Año: 2021 Publicado en: Talanta 233 (2021), 122603 [8 pp.] ISSN: 0039-9140 Factor impacto JCR: 6.556 (2021) Categ. JCR: CHEMISTRY, ANALYTICAL rank: 11 / 87 = 0.126 (2021) - Q1 - T1 Factor impacto SCIMAGO: 0.983 - Spectroscopy (Q1) - Analytical Chemistry (Q1)