Over the past few decades, several techniques have been applied to identify the geographical origins of rice products. In this study, the chemical characterization of polycyclic aromatic hydrocarbons (PAHs) was carefully conducted by analysing PAHs in rice samples collected from private sector planting areas located in Bali and Yogyakarta, Indonesia (i.e. ID; n = 20), west sides of Malaysia (i.e. MY; n = 20), Mandalay, Legend, Myingyan, Myanmar (i.e. MM; n = 20), northern parts of Lao PDR (i.e. LA; n = 20), central parts of Cambodia (i.e. KH; n = 20), northern parts of Vietnam (i.e. VN; n = 20), and Thailand (i.e. TH; n = 22). Percentage contributions show the exceedingly high abundance of 5–6 ring PAH congeners in rice samples collected from Indonesia, Malaysia, Thailand, Myanmar, Cambodia and Vietnam. Lao PDR rice samples were overwhelmed by 4-ring PAH congeners with the percentage contribution of 46% followed by 5–6 ring PAHs (33%) and 3-ring PAHs (21%). In addition, hierarchical cluster analysis and principal component analysis can successfully categorize some rice samples based on its geographical origins.

在过去的几十年里，已经应用了几种技术来识别大米产品的地理来源。在这项研究中，通过分析从位于印度尼西亚巴厘岛和日惹（即 ID； n  = 20）、马来西亚西部的私营部门种植区采集的水稻样品中的 PAHs，仔细进行了多环芳烃 (PAHs) 的化学表征。即MY；n  = 20)、曼德勒、Legend、Myingyan、缅甸（即MM；n  = 20）、老挝人民民主共和国北部（即LA；n  = 20）、柬埔寨中部（即KH；n  = 20） 、越南北部（即 VN；n  = 20）和泰国（即 TH；n = 22)。百分比贡献表明从印度尼西亚、马来西亚、泰国、缅甸、柬埔寨和越南采集的水稻样品中 5-6 环 PAH 同系物的丰度非常高。老挝人民民主共和国水稻样品被 4 环 PAH 同系物淹没，占 46%，其次是 5-6 环 PAH（33%）和 3 环 PAH（21%）。此外，层次聚类分析和主成分分析可以成功地根据其地理来源对一些水稻样本进行分类。