Evaluation of the Concentration of Cu, Zn, Pb and Cr in Different Fish Species from the São Gonçalo Channel in Pelotas-RS, Brazil

The objective of this study was to evaluate the concentration of Cu, Zn, Cr and Pb in different species of fish collected in the estuarine and limnic regions of the São Gonçalo channel, located in the Patos-Mirim lagoon complex in the coastal plain of Rio Grande do Sul State (Southern Brazil) during 2013 (autumn, winter and spring) and 2014 (summer). Fish samples were decomposed in a digester block with a reflux system under conditions optimized using a central composite design as it follows: 250 mg of fish sample, 5 mL HNO3, 2 mL H2O2 during 2 h at 150 °C. The concentrations obtained ranged from 6.7 to 12.0 mg kg -1 for Cu; 1.8 to 23.6 mg kg -1 for Zn; 37 to 487 µg kg -1 for Pb; and 40 to 1268 µg kg -1 for Cr. The highest concentrations of Cu, Zn and Pb, were observed in fishes collected at locations in the estuarine region and Cr showed high levels, especially in the limnic region. The samples of the species Loricariichthys anus (viola) showed the highest concentrations of all analytes investigated.

本研究旨在评估2013年（秋季、冬季及春季）与2014年（夏季）期间，采自巴西南里奥格兰德州沿海平原帕托斯-米里姆泻湖群内圣贡萨洛海峡的河口与淡水区域的不同鱼类物种中铜（Cu）、锌（Zn）、铬（Cr）及铅（Pb）的含量。鱼类样品采用带有回流系统（reflux system）的消解块（digester block）进行消解，消解条件通过中心复合设计（central composite design）优化确定：称取250 mg鱼类样品，加入5 mL硝酸（HNO3）与2 mL过氧化氢（H2O2），于150 ℃下反应2小时。测得的浓度范围如下：铜为6.7~12.0 mg·kg⁻¹，锌为1.8~23.6 mg·kg⁻¹，铅为37~487 μg·kg⁻¹，铬为40~1268 μg·kg⁻¹。铜、锌与铅的最高含量见于河口区域采集的鱼类样本，而铬的高含量则主要集中在淡水区域采集的样本中。其中，洛里卡里奇蒂斯·阿努斯（Loricariichthys anus，俗称viola）的样本，其所有被测分析物的含量均为所有样本中的最高值。