Adaptation of the acetone method for the δ N-NO analysis of saline water with a low concentration of nitrate.

Rationale: The recently reported acetone method for δ N-NO analysis is a straightforward sample preparation process. However, the applicability of the method to water samples having high salinity and low concentration of nitrates is not good. Therefore, we developed a new method to measure δ N-NO values in a saline sample having low nitrate concentration by improving the acetone method (the adapted method), and verified its usability.