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.

Resumo Este estudo teve como objetivo avaliar a capacidade de fitorremediação e bioindicação da macrófita aquática Sagittaria montevidensis, utilizando como parâmetros a bioconcentração e translocação de metais pesados. Foi realizada uma amostragem simples em quatro locais na região de Pelotas, sul do Brasil, na qual foram coletadas plantas, águas e sedimentos. As plantas foram submetidas a digestão ácida nítrico-perclórica e os sedimentos sofreram a extração pseudo-total de digestão ácida. A determinação dos elementos Cr, Cu, Pb, Ni e Zn nos extratos foi realizada por espectrometria de absorção atômica em chama. Também foram realizados ensaios físico-químicos em amostras de água, incluindo pH, condutividade elétrica, cloretos, alcalinidade, dureza e matéria orgânica e, em amostras de sedimentos, umidade e teor de matéria orgânica. A macrófita aquática estudada apresentou Fator de Bioconcentração (FBC) e Fator de Translocação (FT), principalmente de Ni. Os resultados obtidos mostraram que a macrófita aquática da espécie S. montevidensis possui capacidade para fitoextração, principalmente de Ni e potencial para bioindicação de Cu, Ni e Zn.

Abstract This study evaluated the bioindication and phytoremediation capacity of the aquatic macrophyte Sagittaria montevidensis by using it to assess the bioconcentration and translocation of heavy metals. A simple sampling was conducted at four sites in the region of Pelotas, southern Brazil, where plants, water and sediments were collected. The plants were subjected to nitric-perchloric acid digestion and the sediments underwent pseudo-total acid digestion. The determination of the elements Cr, Cu, Pb, Ni and Zn in the extracts was performed by flame atomic absorption spectrometry. Physicochemical tests were also carried out on water samples, including pH, electrical conductivity, chlorides, alkalinity, hardness and organic matter, and in sediment samples, moisture and organic matter content. The macrophyte study indicated a Bioconcentration Factor (BCF) and a Translocation Factor (TF), especially for Ni. The results showed that the aquatic macrophyte species S. montevidensis has a phytoextraction capacity, mainly for Ni, and potentially for bioindication of Cu, Ni and Zn.

This paper describes the development of a methodology for solid phase extraction (SPE) and pre-concentration of nitrosamines from aqueous samples using granular activated charcoal as stationary phase. micelar electrokinetic capillary Chromatography (MEKC) was used for the separation and identification of the nitrosamines in the extracts. Using a sample with 50 µg l-1 of each nitrosamines standards (dimethylnitrosamine, DMN; diethylnitrosamine, DEN; N-nitrosopyrrolidine, NPYR; N-nitrosopiperidine, NPIP; N-nitrosomorpholine, NMOR), the methodology showed a range of recuperation from 29 to 107% with a linear zone between 10 and 500 µg l-1. The developed methodology can be applicable to the determination of these analytes in different aqueous samples.