This study examines the chemical composition and antioxidant properties of iron walnut oil (IWO) from different Chinese regions, using ultra-high-performance liquid chromatography-quadrupole time-of-flight mass spectrometry for the analysis of phenolic compounds. Regional variations were identified in fatty acid profiles, with elevated α-linolenic acid levels observed in samples from cooler climates (e.g., Liaoning, sample 1) that were 60% higher than in samples from warmer regions (e.g., Sichuan, sample 2). Antioxidant properties, quantified ...