Revista Eletrônica de Química; Revista Virtual de Quimica; Virtual Journal of Chemistry

The Indian clove, Syzygium aromaticum [L] Merr. et Perry, has been popularly used in the treatment of several diseases. A more recent use of this spice in Brazil is a homemade formulation, based on the ethanolic extraction of the dried flower buds of S. aromaticum, which has shown to be efficient as mosquitoes repellent. Here we evaluated, through the development of a GC analytical technique, the concentrations of the main components of the ethanolic extract of Indian cloves (eugenol and eugenyl acetate), and possible responsible for the repellent activity, in this homemade formulation. Our results corroborated the efficiency of this protocol to extract eugenol and eugenyl acetate and established the ideal conditions for extraction. DOI: 10.5935/1984-6835.20140086O cravo-da-índia, Syzygium aromaticum [L] Merr. Perry et, é popularmente usado no tratamento de várias doenças. Uma utilização mais recente dessa especiaria no Brasil é uma formulação caseira, com base na extração de etanol dos botões florais secos de S. aromaticum, que se mostrou eficiente como repelente contra mosquitos. Aqui nós avaliamos por meio do desenvolvimento de uma técnica analítica utilizando CG, as concentrações dos principais componentes do extrato etanólico do cravo (eugenol e acetato de eugenila), possíveis responsáveis pela atividade repelente, nesta formulação caseira. Nossos resultados corroboram a eficiência deste protocolo para extrair eugenol e acetato de eugenila, e estabeleceu as condições ideais para extração, além da caracterização dos compostos. DOI: 10.5935/1984-6835.2014008

Extra virgin olive oil (EVOO) is valued for its flavor and health benefits. However, its quality can decline during storage, reducing food quality and the effectiveness of therapeutic compounds when used as a pharmaceutical excipient. While the oxidative stability of extra virgin olive oil has been widely studied for food quality and shelf life, its crucial role as a pharmaceutical excipient and the impact of long-term degradation on the effectiveness and stability of active compounds remain largely unexplored. This study examined 14 commercial EVOO samples immediately after opening and after three years of storage. Standard methods were used to measure the peroxide value, p-anisidine value, acidity, antioxidant activity, and extinction coefficients. The data were analyzed with statistical and chemometric tools. Initially, all oils met international quality standards. After three years, most samples showed significant deterioration, especially a decline in antioxidant activity and an increase in K232 values. Statistical tests confirmed differences among samples, and pairwise comparisons indicated significant differences consistent with degradation between T0 and T1. Principal component analysis (PCA) identified three main patterns related to oxidation and antioxidant capacity, and clustering distinguished between stable and unstable samples. Overall, the stability of the studied EVOOs varied by brand, influenced by their natural composition and storage conditions. Multivariate analysis confirmed that antioxidant activity and extinction coefficients are key indicators of oxidative degradation. This finding highlights multivariate analysis as a valuable approach for monitoring the oxidative stability of oils and ensuring EVOO quality for both food and pharmaceutical application.

Recently, there has been a worldwide problem of increased bee mortality (Colony Collapse Disorder) and the intensive use of pesticides is suspected as one of the causes. Honey samples are one of many indicators to assess bee exposure to pesticides. In this work, a method for the simultaneous analysis of the pesticide Fipronil and its degradation products in honey samples by gas chromatography with electron capture detector (GC-ECD) is presented and validated. The extraction procedure was investigated using C18-SPE with different solvents and methanol showed the best performance. The analytical quantification was performed by internal standard matrix-matched calibration, which resulted in analytical curves presenting correlation coefficients higher than 0.99. The proposed method was validated with good results, such as recoveries around 70 - 99%, limits of detection and quantification bellow 0.014 and 0.072 μg mL-1, respectively, and relative standard deviations below 7%. The method is simple, effective and was successfully applied to 28 commercial honey samples, regular and organic, from different floral sources. The results showed the presence of fipronil desulfinyl, the main degradation product of fipronil, in some samples, even among the organic ones.