Advancing ethanol content determination in hydrogels: non-destructive and operational methods for health and criminal inspections.

The significance of accurate determination of ethanol content in hydrogel formulations was accentuated during COVID-19 pandemic coinciding with the heightened demand for sanitizing agents. The present article proposes three robust methodologies for this purpose: Fourier Transform Infrared Spectroscopy (FTIR), Raman spectroscopy, and Densitometry with matrix effect correction by Near-Infrared Spectroscopy (NIR). All three methods demonstrated outstanding linearity (R2 ≥ 0.99) and minimal errors (< 1.7%), offering simplicity and operational efficiency. FTIR and Raman, being non-destructive and requiring minimal preparation, enable practical on-site analysis capabilities, underscoring the potential of the spectroscopic methods to expedite health investigations and inspections, empowering on-site ethanol determination, and relieving the burden on official laboratories. Additionally, the densitometry with NIR-based approach showcased superior accuracy and precision compared to spectroscopic methods, meeting validation criteria while offering operational advantages over the costly official distillation-based method. Therefore, it stands as a reliable and reproducible technique for comprehensive health and criminal compliance assessments, making it a compelling alternative for both industry and official laboratories.

The anesthetic efficacy of eugenol and the essential oils of Lippia alba and Aloysia triphylla in post-larvae and sub-adults of Litopenaeus vannamei (Crustacea, Penaeidae).

The aim of this study was to evaluate the anesthesia induction and recovery times of sub-adult and post-larvae white shrimp (Litopenaeus vannamei) that were treated with eugenol and the essential oils (EOs) from Lippia alba and Aloysia triphylla. Oxidative stress parameters in the hemolymph of this species were also analyzed. The concentrations of eugenol, A. triphylla EO and L. alba EO recommended for anesthesia were 200, 300 and 750 µL L(-1) for sub-adults and 175, 300 and 500 µL L(-1) for post-larvae, respectively. The concentrations studied during the transport of sub-adults were between 20 and 50 µL L(-1) eugenol, 20-30 µL L(-1)A. triphylla EO and 50 µL L(-1)L. alba EO. For post-larvae, the optimal concentrations for transport were 20 µL L(-1) eugenol and between 20 and 50 µL L(-1)A. triphylla EO. The white shrimp sub-adults that were exposed to A. triphylla EO (20 µL L(-1)) showed increases in their total antioxidant capacities (150%), catalase (70%) and glutathione-S-transferase (615%) activity after 6 h. L. alba EO (50 µL L(-1)) and eugenol (20 µL L(-1)) also increased GST activity (1292 and 1315%) after 6 h, and eugenol (20 µL L(-1)) decreased the total antioxidant capacity (100%). Moreover, concentrations above 30 µL L(-1) for the EOs of A. triphylla and L. alba and 20 µL L(-1) eugenol were effective at inducing anesthesia and improving the antioxidant system against reactive oxygen species (ROS) after 6 h.