Arsenic content of soils from three regions of Santa Catarina State

Abstract The determination of trace elements is necessary in order to monitor their entry into the soil system and to remediate contaminated areas. The purpose of this study was to determine the natural content of arsenic (As) in soils of three regions of Santa Catarina State (SC): the Southern Plateau, the Metropolitan area and the Southern Coast. Arsenic content was obtained after digestion in a microwave oven, following the USEPA 3051 A protocol and quantification was made by atomic absorption spectrometry with electrothermal atomization. The results were analyzed by the Scott-Knott test at a 5% significance level. Soil attributes that best correlated with arsenic content were clay, organic carbon, cation exchange capacity and Al and Fe oxides. The arsenic levels are related to the source material and the slope of regional soils.

摘要：为监测微量元素进入土壤系统的过程并修复受污染区域，对其开展定量检测具有重要意义。本研究旨在测定圣卡塔琳娜州（Santa Catarina State，SC）南部高原、大都会区以及南部海岸三个区域土壤中砷（As）的自然本底含量。实验遵循美国环境保护署（U.S. Environmental Protection Agency，USEPA）3051A标准方法，通过微波消解法完成样品前处理，随后采用电热原子化原子吸收光谱法对砷含量进行定量分析。以5%的显著性水平，采用Scott-Knott检验对实验结果进行统计分析。与砷含量相关性最强的土壤属性包括黏粒（clay）、有机碳（organic carbon）、阳离子交换量（cation exchange capacity）以及铝氧化物（Al oxides）与铁氧化物（Fe oxides）。土壤砷含量与成土母质及区域土壤坡度密切相关。