Identification of the origin and water type of various Korean bottled waters using strontium isotopes

• We investigate three types of bottled waters originating from South Korea.
• The 87Sr/86Sr ratios of bottled waters provide specific information on their origins.
• The δ18O values of Korean bottled waters are characterized by a latitude effect.

Bottled water consumption is steadily expanding in the Korean market. However, the potential exists for fraudulent product labeling, and misrepresentation of the product quality either during collection or manufacturing could be detrimental to consumer health. As a traditional geochemical tracer, strontium isotope ratios (87Sr/86Sr) have been used in many studies to identify the origin of the water product. Here, we investigated three types of bottled water from South Korea, still water (STW), sparkling water (SPW), and desalinated marine water (MAW), and used strontium isotope ratios (87Sr/86Sr) and other geochemical parameters to identify the water origin and treatment history. The 87Sr/86Sr ratios ranged widely from 0.70503 to 0.75589, with average values of 0.72019 for STW, 0.71605 for SPW, and 0.70997 for MAW. The 87Sr/86Sr ratios of MAW were higher than those of seawater, indicating that they experienced post-treatment processing after desalination. In contrast, the 87Sr/86Sr ratios of STW and SPW were distinctly grouped according to their bedrock origins. The relationships between the 87Sr/86Sr and elemental ratios provided direct information on the origin of the bottled water and differences within the same lithology. In addition, the latitude effect on the δ18O values was directly related to the 87Sr/86Sr ratios, with a negative correlation apparent between them.