Pharmaceuticals, pesticides and metals/metalloids in Lake Guaíba in Southern Brazil: Spatial and temporal evaluation and a chemometrics approach.

Compiling and reporting data related to the presence of pharmaceuticals and pesticides are crucial means of assessing the risk those chemicals pose to human health and environment. Data sets from different sources were combined using a data fusion approach to produce a spatial and temporal variation of contaminants presents in water from Lake Guaíba (29°55'-30°24' S; 51°01'-51°20' W). Lake Guaíba is a 496 km water body situated in the geological depression of Rio Grande do Sul State, Brazil; that is fed by several rivers from the metropolitan area, the 5th largest metro area in Brazil, with approximately 5 million inhabitants.

Multivariate optimization for extraction of pyrethroids in milk and validation for GC-ECD and CG-MS/MS analysis.

A simple and inexpensive method based on solvent extraction followed by low temperature clean-up was applied for determination of seven pyrethroids residues in bovine raw milk using gas chromatography coupled to tandem mass spectrometry (GC-MS/MS) and gas chromatography with electron-capture detector (GC-ECD). Sample extraction procedure was established through the evaluation of seven different extraction protocols, evaluated in terms of analyte recovery and cleanup efficiency. Sample preparation optimization was based on Doehlert design using fifteen runs with three different variables.