Solid-phase extraction of nitro-PAH from aquatic samples and its separation by reverse-phase capillary liquid chromatography

Abstract

Neste trabalho é proposta uma metodologia analítica para extrair 1-nitronaftaleno, 2-nitrofluoreno, 9-nitroantraceno, 3-nitrofluoranteno e 1-nitropireno como compostos modelos para nitropoliaromáticos (nitro-HPA) em amostras aquáticas. A cromatografia líquida capilar com detecção UV on-column (μLC-UV) foi empregada para separar e quantificar todos os cinco nitro-HPA extraídos. Duas técnicas diferentes de extração foram testadas e comparadas: extração líquido-líquido (LLE) e extração em fase sólida (SPE) com dois diferentes tipos de sorbentes: partículas octadecilssilica (C 18 ) e estireno divinilbenzeno (XAD-2). A eluição dos analitos foi testada com diclorometano e acetonitrila. O melhor resultado de recuperação foi obtido para extração SPE -C 18 com diclorometano com valores variando de 76 a 97% e valores de desvio padrão relativo menores que 4%. As condições cromatográficas para análise foram desenvolvidas empregando uma coluna capilar (250 × 0,3 mm) empacotada com partículas C 18 de 5 μm com eluição isocrática de 65% de acetonitrila em água (v/v) com vazão de 7 μL min -1 . Os limites de detecção obtidos no sistema UV on-column (abrangendo de ~3 a 30 μmol L -1 ) são limitantes para uma aplicação ambiental, porém adequados a estudos de toxicidade.In this work, an analytical methodology to extract 1-nitronaphthalene, 2-nitrofluorene, 9-nitroanthracene, 3-nitrofluoranthene, and 1-nitropyrene aquatic samples is proposed. Capillary liquid chromatography with on-column UV detection (μLC-UV) was employed to separate and quantitate all five nitrated polycyclic aromatic hydrocarbons (nitro-PAH) extracted from water samples. Two different extraction techniques were tested and compared: liquid-liquid extraction (LLE) and solid phase extraction (SPE) with two different sorbents, octadecylsilica (C 18 ) and styrene divinylbenzene (XAD-2) particles. The elution of analytes was tested with both acetonitrile and methylene chloride. The best recovery results were obtained for SPE-C 18 extraction with the methylene chloride with values ranging from 76 to 97% with RSD values smaller than 4%. The chromatographic conditions for analysis was carried out using a 250 × 0.3 μm i.d. packed capillary column with 5 μm C 18 particles. The elution was isocratic with 65% acetonitrile in water (v/v) as mobile phase with a flow rate of 7 μL min -1. The detection limits due to on-column UV detection (ranging ~3 -30 μmol L -1 ) are limiting for environmental applications, however, they are suited for toxicological studies.

Method Validation for SPE Applied to Determination of PAH in Petroliferous Industry Effluent Water

“…Other studies of wastewaters have used Solid Phase Microextraction (SPME) 9 or Solid Phase Extraction (SPE) [10][11][12]. Direct mode SPME is not feasible, due to attack on comercially used fibres by compounds present in produced water.…”

Analysis of trace‐level nitrated polycyclic aromatic hydrocarbons in water samples by solid‐phase microextraction with gas chromatography and mass spectrometry

“…SPE, LLE, and SPME have been used to extract NPAHs from water samples . Compared to other methods, SPME is easier to operate, more economical, and more efficient for the extraction of NPAHs .…”

“…NPAHs were first found in the Suimon river water in the 1980s [15], after which most studies were focused on NPAHs in sediments [15][16][17] making studies in water relatively rare. SPE, LLE, and SPME have been used to extract NPAHs from water samples [18][19][20]. Compared to other methods, SPME is easier to operate, more economical, and more efficient for the extraction of NPAHs [20].…”

The Use of the Silver Solid Amalgam Electrode for Voltammetric Determination of 9-nitroanthracene

“…These compounds are a common part of the air where they are mostly adsorbed on the solid atmospheric particles (dust fractions). NPAHs are identified as a class of genotoxic environmental pollutants (Netto et al 2000;Lopes et al 2005) and the Ames Salmonella test has shown that NPAHs generally are more mutagenic than their parent PAHs (Barek et al 1996;Lopes and deAndrade 1996;Toledo, Lanças, and Carrilho 2007). The position of the nitro group on the aromatic rings significantly affects the metabolism, mutagenicity, and carcinogenicity of these compounds.…”