Fipronil is a pyrazole insecticide used to control undesirable insect populations. Due to its large-scale application, there is the potential for surface waters’ contamination, with toxic action for non-target organisms, and consequent impacts on aquatic ecosystems. Planarians are potential non-target aquatic invertebrates to these insecticides. They are widespread in tropical freshwaters and have been proposed as good candidates to assess the toxic effects of freshwater systems contaminated by insecticides. Thus, the present study aims to evaluate the sublethal concentrations of a fipronil-based insecticide that may affect the planarian physiology. After chronic exposure to Regent 800 WG®, a significant decrease in locomotor velocity (LOEC—6.25 mg·L−1), regeneration of the auricles and photoreceptors (LOEC—3.13 mg·L−1), and reproduction (fecundity—LOEC 12.5 mg·L−1) were observed. The results of our study demonstrate that long-term exposure to a pyrazole insecticide can compromise non-target aquatic invertebrates while reinforcing the need for a better investigation of complementary parameters (such as behavior, regeneration, and reproduction) for a more accurate risk assessment of commercial pesticide toxicity in freshwater systems.

Chlorpyrifos, an organophosphate insecticide widely used to control agricultural pests, poses a significant environmental threat due to its toxicity and persistence in soil and water, causing deleterious effects on non-target organisms. In this context, our work aimed to evaluate the acute (survival) and chronic (regeneration, locomotion and reproduction) toxicity of chlorpyrifos in tropical freshwater planarians Girardia tigrina. The 48h lethal concentration (LC50) of the commercial formulation, containing 480 g L− 1 of chlorpyrifos active ingredient, was determined to be 622.8 µg a.i. L− 1 for planarians. Sublethal effects were also observed, with a significant reduction in locomotion and delayed head regeneration (equal lowest observed effect concentration – LOEC = 3.88 µg a.i. L− 1). Our study highlight the importance of employing physiological and behavioral parameters as effective tools for assessing the ecotoxicological impact of organophosphate insecticides on non-target tropical freshwater organisms, such as G tigrinia. Overall, this study demonstrates the potential of chlorpyrifos-based insecticides to harm natural populations of freshwater planarians at environmentally relevant concentrations. The observed toxicity serves as a cause for concern, emphasizing the need for stricter regulations and careful management of chlorpyrifos usage to mitigate its deleterious effects on aquatic ecosystems. By understanding the specific impacts on non-target organisms like G. tigrina, we can make more informed decisions regarding using and regulating organophosphate insecticides, ultimately promoting sustainable agricultural practices and environmental conservation.

The study of chromatographic techniques, classical and modern, describes the simplicity and, at the same time, the advances that this area has undergone in recent years in quality scientific research and also in learning in undergraduate and postgraduate courses around the world. This paper investigate a characterization by thin layer chromatography (TLC) and gas chromatography coupled with mass spectrometry (GC-MS), as a method developed by graduate students that involve a combination of a classic and modern technique, as well as results about the physicochemical properties of the essential oil of Bauhinia monandra flower. Essential oil was extracted by Clevenger, the TLC was performed in different eluents and developers, and thus the retention factors (Rfs), and the chemical profile by GC-MS were obtained. The essential oil of the flowers showed a yield of 0.06%, positive solubility in ethanol 70%, refractive index of 1.3621, optical rotation of +36.4αD and relative density of 0.941 g mL-1 at 20 °C. In the TLC analysis 18 Rfs were observed after the use of different developers, with the predominant class of oxygenates compounds. In the GC-MS analysis, 7 compounds were observed, being two majorities, characterized as panaxene with 20.51% and the α-guaiene with 33.39%. The essential oil of B. monandra flower showed a predominance of 70.22% of sesquiterpenic compounds. The allied techniques, classic and modern, demonstrated different ways of evaluating the essential oil through its chemical composition, both techniques showed high efficiency and precision, in addition was an appropriate project developed by postgraduate students.