Validation of a multi-residue method and estimation of measurement uncertainty of pesticides in drinking water using gas chromatography-mass spectrometry and liquid chromatography-tandem mass spectrometry.

A rapid and efficient sample extraction using solid-phase extraction coupled with gas- and liquid-chromatography-mass spectrometry was studied for the analyses of 124 different types and chemical groups pesticides from drinking water. The extraction was performed using a Bond Elut Florisil cartridge. The GC analysis was divided into two (analysis 1 and 2), while a single method was used for LC analysis.

In vitro and ex vivo activity of Melaleuca alternifolia against protoscoleces of Echinococcus ortleppi.

Cystic echinococcosis is a zoonotic disease of difficult diagnosis and treatment. The use of protoscolicidal agents in procedures is of utmost importance for treatment success. This study was aimed at analysing the in vitro and ex vivo activity of Melaleuca alternifolia oil (tea tree oil - TTO), its nanoemulsion formulation (NE-TTO) and its major component (terpinen-4-ol) against Echinococcus ortleppi protoscoleces obtained from cattle.

Polychlorinated biphenyls in umbilical cord serum of newborns from Rio Grande do Sul state, Brazil.

Background: Polychlorinated biphenyls (PCBs) are food-chain contaminants that have been shown to contaminate foods worldwide. The newborn are exposed to these organochlorine compounds across the placenta and through breastfeeding. They are proven to be carcinogenic and may contribute to congenital malformation etiology.

Composition and antioxidant capacity of the essential oil of leaves of Vitex megapotamica (Sprengel) Moldenke.

This study is designed to examine the chemical composition and antioxidant activity of the essential oil of Vitex megapotamica. Gas chromatography-mass spectrometry analysis resulted in the detection of 27 components, representing 92.36% of the total oil composition.

Chemical composition and antioxidant activity of the essential oil of Tabernaemontana catharinensis A. DC. leaves.

The essential oils obtained by hydrodistillation from the leaves of Tabernaemontana catharinensis had their composition analysed by GC-MS. A total of 18 substances were identified, consisting of a complex mixture of sesquiterpenes (83.52%), monoterpenes (5.

Isolation and chromatographic analysis of bioactive triterpenoids from the bark extract of Cariniana domestica (Mart) Miers.

The Lecythidaceae family is composed of 25 genera and 400 species that occur in the form of trees with a pantropical distribution. The genera Cariniana belongs to the family Lecythidaceae, and there are few reports considering these species. In this work, fractionation of the dichloromethane fraction obtained from the aqueous extract of the stem bark of Cariniana domestica (Mart) Miers, popularly known as Jequitibá-roxo, led to the isolation of two mixtures of triterpenoids: lupeol and β-amyrin and β-sitosterol and stigmasterol.