Development of a method for determination of dissolved Te species in open ocean water

Tohru Fukazawa1, Daichi Asanuma1, Hajime Obata2, Satoshi Usui3, Shiro Matsuoka3 and Kazuhiro Norisuye3, (1)Graduate School of Science & Technology Niigata University, Niigata, Japan, (2)Univ Tokyo, Kashiwa, Japan, (3)Niigata University, Niigata, Japan
Te is one of the rare metals and especially useful for electronic devices. Te is extremely enriched in marine ferromanganese oxides found in seafloor (Hein et al., 2003). It is important for study of marine geochemistry and marine resource strategy to understand how and where Te enrichment occurs in the global ocean. Previous studies have been performed mainly focusing solid samples and concluded that the behavior of Te redox species in seawater is important for understanding of the Te enrichment mechanism (Hein et al., 2003; Kashiwabara et al., 2014). However, the behavior of Te is poorly known owing to extremely low abundance and difficulty in the analysis.

Mg(OH)2 coprecipitation–graphite furnace atomic absorption spectrometry (AAS) has been reported as one of the method for Te species in seawater (Lee and Edmond, 1985). Although this preconcentration procedure is simple and analytical blanks can be kept low, high contents of Mg(OH)2 precipitate may cause physical interferences in the analytical instrument (Lee and Edmond, 1985/86). Therefore, we have been addressing an alternative technique that is applicable for the analysis of large numbers of seawater samples.

In this study, we have performed basic experiments in order to establish a new method that is composed of preconcentration of Te species by Mg(OH)2 coprecipitation, separation of Te species using ion exchange resin column and measurement with ICP-MS.