Development of methods for determining the total concentration and species of non-metals in seaweed from the Antarctic

Abstract

Antarctic is the main thermal regulator of the Earth, and the characteristics of the climate in the Southern Hemisphere are essentially generated and controlled by masses of cold air coming from this continent. Generally, it is in Antarctic that the first changes undergone by the planet are observed, and the damage caused by climate changes, consequently, is reflected to the rest of the planet. The evolution of different life forms in Antarctic took place under extreme conditions of cold, ice and limited exposure to sunlight. Due to these special conditions, several species present in Antarctic are endemic to the region. Given the uniqueness of Antarctic, chemical information on the composition of its fauna and flora becomes of great importance with regard to environmental issues. Chemical information about Antarctic seaweed reported in the literature is limited to a few organic species and metals. However, information about nonmetals, such as halogens and sulfur, is of great relevance since the determination of these elements can be used for purposes such as marine and atmospheric environmental monitoring. Halogens and sulfur when released into the atmosphere generate reactive species that cause the depletion of the ozone layer. On the other hand, these elements are part of the composition of marine seaweed, presenting important metabolic functions, as well as being essential in the synthesis of several compounds. Thus, in view of the scarcity of information and the importance of determining halogens and sulfur in Antarctic marine species, in this work, methods were developed and optimized for the determination of halogens and sulfur and their species in Antarctic seaweed. By using a multi-technique approach involving different sample preparation methods and high sensitivity determination techniques, it was obtained comprehensive information about total halogens and sulfur concentration, distribution of bromine, iodine, and sulfur in different seaweed fractions in ten seaweed species.