Microwave-Assisted Extraction of Fatty Acids from Cultured and Commercial Phytoplankton Species

(1) Background: The extraction of fatty acids from microalgae and cyanobacteria is mostly performed with organic solvents and laborious procedures. Microwave-assisted extraction (MAE) can be a more effective and environmentally friendly process than traditional extraction (TE), which uses a large volume of solvent and conduction heating. Freshwater phytoplankton inhabits diverse aquatic environments and is a promising source of fatty acids and green precursors in the synthesis of biofuel, including cyanobacterial biomass. Therefore, the aim of this study was to investigate the potential of MAE to extract fatty acids from a Chlorella sp. microalga and two cyanobacteria, namely, Arthrospira sp. and Sphaerospermopsis torques-reginae, for biodiesel production. For this purpose, the lipid content and fatty acid profile of these strains were compared after treating biomass with the two extraction methods. (2) Methods: MAE and TE were used as extraction procedures; gas chromatography\u2013mass spectrometry was used to assess the fatty acid profiles, and X-ray spectroscopy was used to analyze biomass. (3) Results: Although the fatty acid profile of the oil obtained by TE showed higher concentrations of fatty acids, the MAE method was able to extract more types of fatty acids. The variety of fatty acids extracted by the MAE, especially those with unsaturated chains, allowed for better quality biodiesel, presenting advantages over previous methods and studies. According to the analyses, essential fatty acids 16:0, 16:1, and 18:2 were found to be abundant in both cyanobacterial strains and in microalga, showing potential for biofuel production. Additionally, metal composition was determined as its content may indicate potential pro-oxidant influence in biofuel production. (4) Conclusions: MAE is a useful and green strategy to extract fatty acids from freshwater phytoplankton. Cyanobacteria can also be a beneficial source of fatty acids for biodiesel synthesis

Avaliação química e toxicológica de formulações de esteroides anabolizantes androgênicos apreendidas pela Polícia Federal na região sul do Brasil

Anabolic androgenic steroids comprise a class of synthetic substances derived from testosterone developed for therapeutic purposes, but illicitly used by recreational and professional athletes. In this sense, formulations of anabolic agents are controlled or prohibited and, once apprehended by law enforcement agencies, need to be analyzed in order to determine their constituents and their possible toxicity. Therefore, the aims of this study was to evaluate extraction methods, to identify analytically and to determine the cytotoxicity of formulations of anabolic agents apprehended by the Federal Police in the southern region of Brazil. Results indicated that the application of microwaves or ultrasound significantly increased the extraction of anabolic agents from their respective formulations. For Product #1, for example, the use of microwaves or ultrasonic probe extracted, respectively, 37.46 ± 1.36 and 35.69 ± 0.98 mg/tablet, whereas the solid-liquid extraction resulted in 29.63 ± 0.40 mg/tablet of the active chemical substance. In turn, the application of analytical techniques allowed the differentiation of genuine and counterfeit formulations while the evaluation of cytotoxicity indicated that the samples may present toxicity. In this sense, the exposure of Product #10 and #11 in concentrations of 0.5 mg / mL had minimum cell viability. Therefore, extraction methods significantly affected the results and, thus, influenced the detection of potentially toxic compounds to the user.Sem bolsaEsteroides anabolizantes androgênicos compreendem classe de substâncias sintéticas derivadas da testosterona desenvolvidas com um intuito terapêutico, porém utilizadas ilicitamente por atletas recreativos e profissionais. Nesse sentido, as formulações de agentes anabólicos são controladas ou proibidas e, uma vez apreendidas por órgãos de controle, necessitam ser analisadas a fim de determinar seus constituintes e sua provável toxicidade. Nesse sentido, objetivo desse trabalho foi avaliar métodos de extração, identificar analiticamente e determinar a citotoxicidade de formulações de agentes anabólicos apreendidos pela Polícia Federal na região Sul do Brasil. Os resultados indicaram que a aplicação de micro-ondas ou de ultrassom aumentaram significativamente a extração de agentes anabólicos de suas respectivas formulações. Para o Produto #1, por exemplo, o uso de micro-ondas ou de sonda ultrasônica extraiu, respectivamente, 37,46 ± 1,36 e 35,69 ± 0,98 mg/comprimido ao passo que a extração sólido-líquido resultou em 29,63 ± 0,40 mg/comprimido da substância química ativa. Por sua vez, a aplicação de técnicas analíticas permitiu a diferenciação de formulações genuínas de falsificadas ao passo que a avaliação de citotoxidade indicou que as amostras podem apresentar toxicidade. Nesse sentido, a exposição do Produto #10 e #11 em concentrações de 0,5 mg/mL apresentou uma viabilidade celular de 0%. Portanto, os métodos de extração afetaram consideravelmente os resultados e, assim, influenciam na detecção de compostos potencialmente tóxicos ao usuário. Palavras-Chave: Esteroides anabolizantes an

Aplicação forense de nanoparticulas de zinco como reveladores de impressões digitais latentes

O objetivo do trabalho foi avaliar a eficácia de um pó formulado com as NPs ZnO como reveladores de IDL