Establishment of a method for analyzing platinum concentration in wakame and elucidation of its distribution

Abstract

Platinum (Pt) has a wide range of applications and anthropogenic impacts in the aquatic environment are a concern. Pt accumulation in marine organisms begins with primary producers through the food chain, but there are few examples of Pt studies in marine macroalgae, which are producers in the food chain. The objective of this study was to evaluate Pt contamination in the coastal environment by measuring Pt concentrations in wakame seaweed collected in Otsuchi Bay, Iwate Prefecture. Since there was no established method for Pt analysis in seaweeds, we established analytical conditions: total dissolution of seaweeds with HF 0.24 ml/g and HCl 7 ml/g, and solid-phase extraction with an anion exchange resin, which enabled us to measure the concentration. The established method was used to measure Pt concentration in wakame seaweed. The distribution of Pt in the stem and mekabu decreased from the mouth to the back of the bay, while the distribution at the root showed the opposite trend. The results suggest that there are different sources of Pt in the upper and lower parts of the wakame.