Plant uptake and transformation of plastic additives in radish ( Raphanus sativus L .) grown in fortified agricultural soils

BACKGROUND Non‐phthalate plastic additives (NPPAs) are emerging contaminants used as plasticizer alternatives, with potential to enter the food chain through soil–plant transfer. This study evaluated the uptake, translocation, and biotransformation of three NPPAs – 1‐hydroxycyclohexyl phenyl ketone (HCPK), 2,2,4‐trimethyl‐1,3‐pentanediol diisobutyrate (TXIB), and di(2‐ethylhexyl) adipate (DEHA) – in radish ( Raphanus sativus L.) grown in soil fortified at 1 mg kg −1 under individual and mixture exposure conditions. RESULTS A micro‐QuEChERS (quick, easy, cheap, effective, rugged, and safe) extraction was developed for plant tissues, and NPPAs from soil were extracted by solid–liquid extraction; both were analyzed by ultra‐high performance liquid chromatography coupled to quadrupole‐Orbitrap high‐resolution mass spectrometry. After 45 days, none of the parent compounds were detected in plant tissues or soil above their limits of quantification. Non‐targeted analysis identified 24 transformation products (TPs): 8 from HCPK, 13 from TXIB, and 3 from DEHA, most of which have not been previously reported. TPs were predominantly detected in leaf tissues, including phase II conjugates (glucosides, glucuronides, and glutathione‐derived conjugates), suggesting active plant‐mediated biotransformation as the dominant process. A multi‐tool in silico risk assessment combining Cramer classification and ECOSAR acute toxicity predictions indicated that several HCPK‐ and TXIB‐derived TPs retain structural alerts and low predicted LC 50 values, suggesting a potentially higher toxicological concern, requiring experimental validation. CONCLUSION These findings demonstrate that the disappearance of NPPAs in soil–plant systems does not indicate complete detoxification. The mixture of TPs, particularly those from HCPK and TXIB, should be considered in future environmental fate and food safety assessments of plastic additives in agroecosystems.