## 1 Introduction  
Food contact materials (FCMs) are widely used in the food industry to package and store products, playing a critical role in ensuring product stability, extending shelf life, and preserving food quality. To achieve these objectives, FCMs are formulated with a variety of intentionally added substances (IAS), such as monomers, plasticizers, antioxidants, lubricants, UV absorbents, and stabilizers [1; 2]. However, during production, use, or recycling, FCMs may also contain non-intentionally added substances (NIAS) that are not purposefully included in the formulation. NIAS can arise from several sources, including the degradation of polymers or additives, reaction byproducts resulting from incomplete polymerization or improperly cured adhesives, impurities present in the raw materials, and contaminants introduced during recycling processes or through inappropriate consumer use [2; 3]. The complexity of these origins underscores the analytical challenges in identifying and quantifying NIAS, which can migrate into food and potentially pose health risks. The presence of NIAS in FCMs represents a dual challenge. On the one hand, the potential migration of these substances into food poses a human health risk, particularly when the toxicological properties of the NIAS are unknown or poorly characterized [1]. This uncertainty can hinder risk assessments and regulatory decision-making, especially when dealing with genotoxic, endocrine-disrupting, or bioaccumulative substances for which no safety thresholds are established. On the other hand, the chemical diversity and typically low concentration of NIAS make their identification and quantification an analytical challenge. Traditional targeted analytical methods, which rely on prior knowledge of the analytes and the availability of reference standards, are often insufficient to capture the wide array of NIAS present in complex matrices [4]. Consequently, the scientific community has increasingly turned to non-targeted analysis (NTA) approaches, such as non-targeted identification and suspect screening, employing advanced high-resolution mass spectrometry (HRMS) to detect and characterize compounds without prior knowledge about their presence [5; 6]. Regulatory frameworks have evolved in tandem with these analytical advancements to ensure food safety. The European Commission Regulation (EU) No. 10/2011 [7], which was recently amended by Commission Regulation (EU) 2025/351 [8], for instance, establishes specific migration limits for substances in plastic FCMs and mandates that manufacturers assess the potential migration of both IAS and NIAS under worst-case conditions using appropriate food simulants. These regulations require comprehensive migration testing, which involves exposing FCMs to food simulants under controlled conditions that mimic real-world scenarios. However, unlike IAS, NIAS are often not individually regulated, and their assessment relies on general safety principles rather than substance-specific limits. Such regulatory incompleteness underscores the need for robust analytical and toxicological approaches to evaluate potential risks. This makes rigorous testing even more essential to confirm that any migrating substances remain within established safety limits, thereby protecting consumer health and maintaining public trust in food safety standards [7; 8]. The integration of ultra-high-performance liquid chromatography (UHPLC) with HRMS has enabled the simultaneous detection and structural elucidation of a multitude of compounds at trace levels. Techniques such as quadrupole time-of-flight (QTOF) and Orbitrap mass spectrometry have provided the sensitivity, selectivity, and mass accuracy necessary for non-targeted approaches, facilitating the detection of compounds that might otherwise remain undetected [9; 10].