Natural abundance stable isotope ratios have been identified as a potential metric for food source [1]. Understanding the source of food is relevant for brand fidelity of geographically protected foods [2], supply chain quality control [3] and tracing pathogen-infected foods to their origin Picarro L2140-i超高精度液態(tài)水/水汽同位素分析儀 Picarro IM-CRDS水同位素分析儀