Abstract Lychnophora pinaster, known as arnica-mineira, is endemic to campos rupestres, at risk of extinction. The present study aimed to characterize the ecogeography and phenolic constituents of 11 L. pinaster populations collected in the mesoregions North, Jequitinhonha, Metropolitan of Belo Horizonte and Campos das Vertentes in the state of Minas Gerais, Brazil. Phenolic constituents were identified and quantified by Ultra-high performance liquid chromatography- mass spectrometry. Lychnophora pinaster occurs in sites at high altitude (700 and 1498 m), annual rainfall of up to 1455 m, soils with low fertility and predominantly loamy texture. Therefore, it can be considered tolerant to acidic soils, with low availability of nutrient. The most abundant substances in all populations were vitexin (18 – 1345 ng/g) and chlorogenic acid (60 – 767 ng/g). The 11 populations formed four groups in relation to the phenolic constituents, with group 1 consisting of the populations of the North Mesoregion (GM, OD) and Jetiquinhonha (DIMa), group 2, the Metropolitan of Belo Horizonte (SRM, NLSC, SM, RPS, CTRA), group 3, the North Mesoregion (ODMa and DI), and group 4, the Campos das Vertentes (CC). Among the populations, only those from the Metropolitan of Belo Horizonte showed correlation of soil properties with phenolic constituents.

Since their original discovery in 1914, ionic liquids (IL) have been widely examined and explored in chemistry due to their unique physical and chemical properties. Ionic liquids are collectively known as organic salts and have melting points of 100 °C or under. The molten salts most employed in analytical chemistry, including gas chromatography (GC), consist of an organic cation paired with an organic or inorganic anion. This class of materials exhibits negligible vapor pressure and may have their properties (e.g.thermal stability and selectivity) structurally tuned by imparting different moieties to the cation/anion. Currently, there are an estimated 1018possible combinations of IL. In this context, the prospection of highly selective IL-based stationary phases for gas-liquid chromatography has enabled high peak capacity and efficient separations of many critical pairs in complex samples. In this review, we present and discuss fundamental characteristics of ionic liquids and introduce important solvation models for gas-liquid systems. In addition, recent advances and applications of IL in conventional and multidimensional gas chromatography are outlined.

Neste trabalho, um método para a diferenciação de gasolinas de acordo com a sua origem geográfica é proposto. Cromatografia gasosa bidimensional abrangente com detecção por ionização em chama (GC×GC-FID) em conjunto com a análise multivariada foi utilizada para diferenciar amostras de gasolina brasileira de amostras oriundas da Venezuela. A análise de fatores paralelos (PARAFAC) foi utilizada no reconhecimento de padrões dos cromatogramas GC×GC-FID e foi aplicada com êxito na diferenciação das amostras de gasolina. Através da análise dos gráficos de escores e pesos gerados pela análise PARAFAC, foi possível determinar que eluatos de média a alta volatilidade, tanto alifáticos quanto aromáticos, foram responsáveis por essa diferenciação.

In this work, a method for differentiation of gasoline according to its geographical origin is presented. Comprehensive two-dimensional gas chromatography-flame ionization detection (GC×GC-FID) combined with multivariate analysis was used to differentiate Brazilian and Venezuelan gasoline samples. Pattern recognition of the GC×GC-FID chromatograms was performed by parallel factor analysis (PARAFAC) and it was successfully applied for the differentiation of these gasoline samples. Eluates with medium to high volatility, both aliphatic and aromatic, were responsible for this differentiation, based on the inspection of the score and loading graphs generated by PARAFAC.