Publications by authors named "Fabio A Duarte"

The secretion of medicines in breast milk is a crucial topic in clinical medicine. LC-DAD stands out in the literature for its simplicity, cost-effectiveness, and reproducibility. Chromatographic techniques, often coupled with cleaning methods such as μQuEChERS, have proven efficient in analyzing drugs across biological matrices.

View Article and Find Full Text PDF

The presence of Ni and V in crude oil is associated with pollutant emissions, corrosive processes and low-quality products. Nevertheless, the knowledge of the concentration of these elements, helps to predict geochemical characteristics and to bring information about the crude oil source. Moreover, Ni and V can cause problems during the crude oil refining process.

View Article and Find Full Text PDF

This work presents the first report of the application of microwave-induced combustion in disposable vessels (MIC-DV) as a simple and fast sample preparation step for fluoride determination by ion-selective electrode (ISE) in leguminous seeds and oilseeds samples. Several experimental conditions of MIC-DV were evaluated, such as sample mass, absorbing solution, volume of combustion igniter, purging time with oxygen, and the use of successive combustion cycles. The accuracy of MIC-DV/ISE method was evaluated by comparing the results obtained by microwave-induced combustion and determination by ion chromatography, with agreements ranged from 94 to 106%.

View Article and Find Full Text PDF

A simple, fast and promising sample preparation method based on microwave-induced combustion in disposable vessels (MIC-DV) was developed for Cl and S determination in crude oil by inductively coupled plasma optical emission spectrometry (ICP-OES). The MIC-DV consists of a new approach of conventional microwave-induced combustion (MIC). For the combustion, crude oil was pipetted on a disk of filter paper and placed on a quartz holder, followed by the addition of igniter solution (40 μL of 10 mol L NHNO).

View Article and Find Full Text PDF

Rice bran is an agro-industrial by-product of low added value that can be used to complement human nutritional needs. In this work, the profile of minerals, fatty acids and amino acids in brown rice bran was determined, aiming to evaluate its potential to complement the nutritional needs of different age groups, according to recommendations of regulatory agencies. The brown rice bran was supplied by a rice processing industry located in the south of the state of Rio Grande do Sul.

View Article and Find Full Text PDF

The production of sustainable catalytic supports for palladium nanoparticles is always desired, even more so through the recovery of biomass residues. In this sense, two different solids were investigated - chitosan/cellulose film and corn stem biochar - as catalytic supports of palladium nanoparticles. The solids were carefully characterized and tested in the Suzuki-Miyaura reaction, a typical cross-coupling reaction.

View Article and Find Full Text PDF

High amounts of phosphogypsum (PG) are generated in the production of phosphoric acid. Previous literature demonstrates that obtaining rare earth elements (REE) from PG is a promising alternative to managing this waste. However, the reported leaching efficiencies are low in most cases, or drastic leaching conditions are required.

View Article and Find Full Text PDF

Edible seaweed has been widely consumed around the world through oriental cuisine and it is important to monitor the levels of some elements, especially halogens. This study proposes, for the first time, the development of an analytical method using the vortex-assisted matrix solid-phase dispersion (VA-MSPD) combined with alkaline extraction of halogens (F, Cl, Br, and I) in edible seaweed for further determination by ion chromatography. The proposed method was evaluated using edible seaweed of the Nori (Porphyra spp.

View Article and Find Full Text PDF

In this work, high purity graphite, a high chemically stable material, was effectively digested using a single method allowing compatible solutions for the further multitechnique determination of halogens by: ion chromatography (F and Cl), inductively coupled plasma mass spectrometry (Cl, Br and I) and by ion selective electrode (only for F). The recent system using microwave-induced self-ignition (MISI) is based on the strong interaction between microwave radiation and graphite in a closed system pressurized with oxygen (Maxwell-Wagner effect). Carbon-based materials present intense and specific interfacial polarization when exposed to microwave electromagnetic field resulting in a fast heating rate.

View Article and Find Full Text PDF
Article Synopsis
  • Antifouling paint particles (APPs) are generated from boat maintenance and cleaning, leading to their accumulation in nearby soils, which may harm soil organisms.
  • A study on the earthworm Eisenia andrei revealed that exposure to contaminated soil significantly decreased survival, biomass, and reproductive success, with effects increasing at higher concentrations of APPs.
  • The research indicated high levels of metals like copper, zinc, and lead in contaminated soils, exceeding Brazilian legal limits, and emphasizes that the toxic impact of APPs affects not only aquatic ecosystems but also essential soil-dwelling organisms.
View Article and Find Full Text PDF

Products coal tar-based are largely used as concrete structures as protective coatings but some questions about leaching and potential toxic effects remain unclear. A laboratory experiment exposing oysters to miniaturized concrete pillars painted with Lackpoxi N1761 over time was performed and trace elements and 17 PAH were monitored in seawater exposure media, and oyster tissues. The original paint composition was also analyzed, and high concentrations of trace elements and PAH were detected.

View Article and Find Full Text PDF

In this work, two microwave-assisted sample preparation methods based on combustion and ultraviolet digestion for futher determination of Br, Cl, and I in blood by inductively coupled plasma mass spectrometry were proposed. For microwave-induced combustion (MIC), blood was spotted on square pieces of Munktell TFN paper, and water and diluted NHOH were evaluated as absorbing solutions. The stability of the analytes in the spotted blood was also evaluated.

View Article and Find Full Text PDF

Direct analysis of flour was proposed for the determination of Cl and S by an elemental analyzer for the first time. The main operational conditions of the direct solid sampling elemental analysis (DSS-EA) were optimized and calibrated by standard solutions, rather than by certified reference material (CRM). Accuracy was evaluated by the analysis of CRM of rice flour and by comparison with analyte determination by independent techniques, i.

View Article and Find Full Text PDF

Microwave-induced combustion (MIC) system for further Cl, Br, and I determination in granola by inductively coupled plasma mass spectrometry (ICP-MS) was proposed. A high sample mass of granola was pressed as pellets and inserted into the proposed MIC system. Water and NHOH were evaluated as absorbing solutions.

View Article and Find Full Text PDF

A new procedure is proposed for the determination of metal contaminants (Cr, Fe, Mg, Mn, Na and Ni) in polymeric diphenylmethane diisocyanate (PMDI), a raw material used to produce polyurethane polymers. The feasibility of using Zeeman-effect background correction graphite furnace atomic absorption spectrometry (GF AAS) and direct sampling (DS) was evaluated. Calibration using aqueous standard solutions was feasible and chemical modifiers as well as reference materials for this purpose were unnecessary.

View Article and Find Full Text PDF

This work proposes a simple device for thermometric titration using a contactless sensor. A low-cost infrared sensor (around $5) was adapted in a disposable, polystyrene vessel for monitoring the temperature to determine the endpoint of neutralization, redox, and complexation titrations, using a homemade syringe pump to titration control. Open-source software was developed to control the device using the Raspberry Pi platform and to perform automatic endpoint determination.

View Article and Find Full Text PDF

A novel system for sample digestion was proposed based on microwave-induced combustion in disposable vessels (MIC-DV) for trace elements determination by inductively coupled plasma optical emission spectrometry (ICP-OES). As a proof of concept, botanical samples were digested by MIC-DV for further determination of Al, Cr, Cu, Fe, Mn, Sr, and Zn. The system consists of a quartz holder (a modified version of conventional MIC) placed inside disposable polypropylene (PP) vessels.

View Article and Find Full Text PDF

Salt iodization is the main public health policy to prevent and control iodine deficiency disorders. The National Salt Iodization Impact Assessment Survey (PNAISAL) was conducted to measure iodine concentration among Brazilian schoolchildren. A survey including 6-14-year-old schoolchildren from public and private schools from all 26 Brazilian states and the Federal District was carried out in the biennia 2008-2009 and 2013-2014.

View Article and Find Full Text PDF

In this work, some trace elements (As, Cd, Cr, Cu, and Pb) were determined for the first time in the crustacean Sergio mirim (Decapoda: Thalassinidea: Callianassidae) from Southern Coast (Rio Grande, RS) of Brazil. The trace element determination was carried out by graphite furnace atomic absorption spectrometry (GF AAS) and inductively coupled plasma mass spectrometry (ICP-MS). Different microwave radiation-based sample digestion methods were evaluated.

View Article and Find Full Text PDF

The trend toward using plant-based ingredients in aquafeeds has raised important concerns for aquaculture owing to the negative impacts of mycotoxins on fish health; with emphasis for contamination by fumonisin B (FB). The brain is an important target of FB; however, study of the pathways linked to brain damage is limited to an analysis of histopathological alterations. Reports have demonstrated the protective effects of dietary supplementation with diphenyl diselenide (PhSe) in the brains of fish subjected to several environmental insults; nevertheless, its neuroprotective effects in fish fed with diets contaminated with FB remain unknown.

View Article and Find Full Text PDF

Arsenic (As) can contaminate air, soil, water, and organisms through mobilization of natural mineralogical deposits or anthropogenic actions. Inorganic-As compounds are more toxic and widely available in aquatic environments, including drinking water reservoir catchments. Since little is known about its effects on prepubertal mammals, the present study focused on it.

View Article and Find Full Text PDF

Ten different adsorbent materials were tested to adsorb indium (III) from leachates of LCD screens, aiming to concentrate this valuable material. Artificial neural network (ANN) and adaptive neuro-fuzzy inference system (ANIFS) were applied to analyze the indium (III) adsorption. The input variables for the network models were: specific surface area, point of zero charge, adsorbent dosage and contact time.

View Article and Find Full Text PDF

This work developed a new technique and an application of an existing approach to determine sodium in food sauces, involving enthalpimetric reactions in the infrared. Infrared Thermometric Titration (TT-IR) was utilized, with simple analyzers and low-cost measurement instruments for the acquisition of the surface temperature generated in the sodium precipitation reaction and development of software for the acquisition and processing of data using Raspberry Pi. The sodium was also quantified by Thermal Infrared Enthalpimetry (TIE), a recently developed technique.

View Article and Find Full Text PDF

The aim of this study was to determine whether purinergic signaling is a pathway associated with fumonisin B (FB)-induced impairment of immune and hemostatic responses. We also determined whether dietary supplementation with diphenyl diselenide (PhSe) prevents or reduces these effects. Splenic nucleoside triphosphate diphosphohydrolase (NTPDase) activity for adenosine triphosphate (ATP) and adenosine diphosphate (ADP) as substrates and total blood thrombocytes counts were significant lower in silver catfish fed with FB1-contaminated diets than in fish fed with a basal diet, while splenic adenosine deaminase (ADA) activity and metabolites of nitric oxide (NOx) levels were significant higher.

View Article and Find Full Text PDF