Distribution and cycle of arsenic compounds in the ocean

• Published in: Applied Organometallic Chemistry
• Main Authors: Santosa, Sri Juari, Wada, Satoshi, Tanaka, Shigeru
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 1994
• Subjects: Antarctic; Indian; Pacific; Syowa Station; The Antarctic; Antarc*
• Online Access: http://dx.doi.org/10.1002/aoc.590080319; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1002%2Faoc.590080319; https://onlinelibrary.wiley.com/doi/pdf/10.1002/aoc.590080319

Abstract In order to understand the distribution and the cycle of arsenic compounds in the marine environment, the horizontal distributions of arsenic(V) [As(V)], arsenic(III) [As(III)], monomethylarsonic acid (MMAA) and dimethylarsinic acid (DMAA) in the Indian Pacific Oceanic surface waters have been investigated. This took place during cruises of the boat Shirase from Tokyo to the Syowa Station (15 November–19 December 1990), of the tanker Japan Violet from Sakai to Fujayrah (28 July–17 August 1991) and of the boat Hakuho ‐ maru from Tokyo to Auckland (19 September–27 October 1992). Vertical distributions of arsenic in the west Pacific Ocean have also been investigated. The concentration of As(V) was found to be relatively higher in the Antarctic than in the other areas. Its concentration varied from 340 ng dm −3 (China Sea) to 1045 ng dm −3 (Antarctic). On the other hand, the concentrations of the biologically produced species, MMAA and DMAA, were extremely low in the Antarctic and southwest Pacific waters. Their concentrations in Antarctic waters were 8 ng dm −3 and 22 ng dm −3 and those in the southwest Pacific were 12 ng dm −3 and 25 ng dm −3 . In the other regions the concentration varied from 16 ng dm −3 (China Sea) to 36 ng dm −3 (north Indian Ocean) for MMAA and from 50 ng dm −3 (east Indian Ocean) to 172 ng dm −3 (north Indian Ocean) for DMAA. As a result, with the exception of Antarctic and southwest Pacific waters, the percentages of each arsenic species in the surface waters were very similar and varied from 52% (east Indian Ocean) to 63% (northwest Pacific Ocean) for As(V), from 22% (northwest Pacific Ocean) to 27% (east Indian Ocean) for As(III) and from 15% (northwest Pacific Ocean) to 21% (north and east Indian Oceans) for the methylated arsenics (MMAA+DMAA). These percentages in Antarctic waters were 97%, 0.2% and 2.8%, respectively, and those in the southwest Pacific Ocean were 97% for As(V)+As(III) and 3% for MMAA+DMAA. The very low concentrations of the biologically produced species in ...