Are there pharmaceutical compounds in sediments or in water? Determination of the distribution coefficient of benzodiazepine drugs in aquatic environment.

Alprazolam, clonazepam and diazepam are drugs belonging to the benzodiazepine class. These drugs might be important environmental contaminants in aquatic media. A total understanding of behavior and fate of drugs in aquatic environment is not available for these and other drugs.

In vitro bioaccessibility of Al, Cu, Cd, and Pb following simulated gastro-intestinal digestion and total content of these metals in different Brazilian brands of yerba mate tea.

Yerba mate tea contains various biochemically active substances. However, it can contain toxic metals. Thus, this work reports the total concentrations of Cd, Cu, Pb and Al in the commercial products, as well as the concentrations in infusions prepared.

Ultrasound-assisted emulsification microextraction combined with graphite furnace atomic absorption spectrometry for the chromium speciation in water samples.

A simple method was proposed by ultrasound-assisted emulsification microextraction (UAEME) combined with GF AAS for Cr speciation in water samples using tributhylphosphate (TBP) as extractor solvent and dispersion with ultrasound, without disperser solvent. The selective separation and pre-concentration of Cr(VI) species in an aqueous medium with HCl and NaCl was optimized with Rotatable Central Composite Design. Total Cr was determined after oxidation of Cr(III) to Cr(VI) by KMnO.

Determination of Cu, Cd, Pb and Cr in yogurt by slurry sampling electrothermal atomic absorption spectrometry: A case study for Brazilian yogurt.

A slurry sampling electrothermal atomic absorption spectrometric method is proposed for the determination of trace elements such as Cu, Cr, Cd and Pb in yogurt. The main factors affecting the slurry preparation were optimized: nature and concentration of acid solution and sonication time. The analytical method was validated in-house by calibration, linearity, limits of detection and quantification, precision and accuracy test obtaining satisfactory results in all cases.

Direct Determination of Nimesulide in Natural Waters and Wastewater by Cathodic Stripping Voltammetry.

Pharmaceuticals are included in a group of compounds considered as contaminants of emerging concern (CECs) in environmental matrices. The quantification of CECs is typically accomplished using chromatographic methods that require several sample pretreatment steps. The current study proposes a voltammetric method to quantify directly nimesulide (NIM) in aqueous samples.

Determination of labile species of As(V), Ba, Cd, Co, Cr(III), Cu, Mn, Ni, Pb, Sr, V(V), and Zn in natural waters using diffusive gradients in thin-film (DGT) devices modified with montmorillonite.

A binding phase based on the clay mineral montmorillonite (MT) was used as a sorbent in this work, which employed diffusive gradients in thin-film (DGT) devices to determine the lability of trace elements in natural waters. Montmorillonite exhibits low cost, wide availability, ease of handling, high ion-exchange capacity, and reusability. As(V), Ba, Cd, Co, Cr(III), Cu, Mn, Ni, Pb, Sr, V(V), and Zn were quantitatively sorbed by MT and eluted with 1.

New approach to the determination of contaminants of emerging concern in natural water: study of alprazolam employing adsorptive cathodic stripping voltammetry.

Contaminants of emerging concern (CECs) are chemicals, including pharmaceutical and personal care products, not commonly monitored in the aquatic environment. Pharmaceuticals are nowadays considered as an important environmental contaminant. Chromatography methods which require expensive equipment and complicated sample pretreatment are used for detection of CECs in natural water.

Relationship between geographical origin and contents of Pb, Cd, and Cr in honey samples from the state of Paraná (Brazil) with chemometric approach.

The aim of this study was to determine the trace elements, Pb, Cd, and Cr in honey samples from eight different regions from the state of Paraná (Brazil), using slurry sampling graphite furnace atomic absorption spectrometry. Chemometric analysis (principal component analysis (PCA)) was applied to classify honey samples according to their levels of the trace elements Pb, Cd, and Cr, which is also related to the geographical origin of honey samples. The mean concentration for the elements followed the order Pb > Cr > > Cd.

Direct determination of Cd, Pb and Cr in honey by slurry sampling electrothermal atomic absorption spectrometry.

Slurry sampling electrothermal atomic absorption spectrometry was used for direct determination of Cr, Pb and Cd in honey without sample pretreatment. The honey slurries were prepared in aqueous solution containing hydrogen peroxide and nitric acid. The slurries were directly introduced in the pyrolytic graphite tubes.

Identification of copper sources in urban surface waters using the principal component analysis based on aquatic parameters.

The goal of this work was to identify the sources of copper loads in surface urban waters using principal component analysis under the aquatic parameters data evaluation approach. Water samples from the Irai and Iguacu rivers were collected monthly during a 12-month period at two points located upstream and downstream of a metropolitan region. pH, total alkalinity, dissolved chloride, total suspended solids, dissolved organic matter, total recoverable copper, temperature, and precipitation data provided some reliable information concerning the characteristics and water quality of both rivers.