Spatial-temporal occurrence of contaminants of emerging concern in urban rivers in southern Brazil.

The widespread use and misuse of antibiotics and pesticides has been linked with several risks to the environment and human health. In the present report, the results of the monitoring of 64 pharmaceuticals and 134 pesticides occurrence in an urban river in Southern Brazil are presented and discussed. Sampling campaigns have covered the period 2016-2018.

Multi-residue methodology for quantification of antiparasitics in hen eggs by LC-MS/MS: development, validation and application to 348 samples from Brazil.

Analytical methodology for quantification of 15 antiparasitic drugs and their respective metabolites in laying hen eggs was optimized and validated. The method uses acetonitrile as solvent extraction, sodium chloride for salting-out, low-temperature purification and analysis by LC-MS/MS. A total of 348 egg samples were collected in 11 states of Brazil and 50% of the total samples presented antiparasitic residues, which were albendazole, fipronil, fenbendazole, ivermectin, oxibendazole and mebendazole.

In silico toxicity evaluation for transformation products of antimicrobials, from aqueous photolysis degradation.

This study investigates degradation processes of three antimicrobials in water (norfloxacin, ciprofloxacin, and sulfamethoxazole) by photolysis, focusing on the prediction of toxicity endpoints via in silico quantitative structure-activity relationship (QSAR) of their transformation products (TPs). Photolysis experiments were conducted in distilled water with individual solutions at 10 mg L for each compound. Identification of TPs was performed by means of LC-TOF-MS, employing a method based on retention time, exact mass fragmentation pattern, and peak intensity.

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.

Toxicity of acrylamide after degradation by conjugated (UV/HO) photolysis in microalgae.

Acrylamide (AA) is routinely used in laboratories and industries, and its disposal is always a problem; consequently, offering an alternative for their treatment contributes to conducting research in a responsible way. Therefore, in this work, acrylamide solutions were degraded by ultraviolet radiation and hydrogen peroxide (HO), and their toxicity was evaluated using a Desmodesmus quadricauda microalgae growth assay. The AA solutions were exposed to different dosages of HO and different exposure times to UV radiation.

Presence of antibiotic resistance genes and its association with antibiotic occurrence in Dilúvio River in southern Brazil.

It is known that antibiotics are widely used in human and veterinary medicine. In some countries the use is controlled, however few restrictions to their use are enforced in many countries. Antibiotics and their metabolites can reach the water bodies through sewage systems, especially in those countries with partial or absent wastewater treatment systems.

Pseudallescheria boydii and Meyerozyma guilliermondii: behavior of deteriogenic fungi during simulated storage of diesel, biodiesel, and B10 blend in Brazil.

Due to their renewable and sustainable nature, biodiesel blends boost studies predicting their stability during storage. Besides chemical degradation, biodiesel is more susceptible to biodegradation due to its raw composition. The aim of this work was to evaluate the deteriogenic potential (growth and degradation) of Pseudallescheria boydii and Meyerozyma guilliermondii in degrading pure diesel (B0), pure biodiesel (B100), and a B10 blend in mineral medium during storage.

An LC-ESI-MS/MS method for residues of fluoroquinolones, sulfonamides, tetracyclines and trimethoprim in feedingstuffs: validation and surveillance.

An increasing concern about food safety has been observed over the years. The presence of drugs residues in food is one of the major subjects of research in food safety. Feedingstuffs can be responsible for carryover into the food chain of residues of several drugs.

Transformation products of amoxicillin and ampicillin after photolysis in aqueous matrices: Identification and kinetics.

Antibiotics are widely used in human medicine and veterinary production. Residues of these compounds reach the water sources through waste or direct application (e.g.

Methodology for trace analysis of 17 pyrethroids and chlorpyrifos in foodstuff by gas chromatography-tandem mass spectrometry.

This study aimed to develop an efficient, sensitive, and reliable analytical method for trace analysis of 17 different pyrethroids and chlorpyrifos in the fatty content of animal products, including beef, chicken, eggs, fish, and milk. The method developed is based on an ultrasound extraction using lyophilized samples, a solid phase extraction cleanup with basic alumina and C18 cartridges in tandem, and analysis by gas chromatography coupled to tandem mass spectrometry in negative chemical ionization mode. Recovery values were in the range of 27-128 % with relative standard deviation always below 25 %, and chiral analysis of recovery data showed predominance of isomers of cis form over trans.

Determination of aminoglycoside residues in milk and muscle based on a simple and fast extraction procedure followed by liquid chromatography coupled to tandem mass spectrometry and time of flight mass spectrometry.

Antibiotics are widely used in veterinary medicine mainly for treatment and prevention of diseases. The aminoglycosides are one of the antibiotics classes that have been extensively employed in animal husbandry for the treatment of bacterial infections, but also as growth promotion. The European Union has issued strict Maximum Residue Levels (MRLs) for aminoglycosides in several animal origin products including bovine milk, bovine, swine and poultry muscle.

High-throughput method for macrolides and lincosamides antibiotics residues analysis in milk and muscle using a simple liquid-liquid extraction technique and liquid chromatography-electrospray-tandem mass spectrometry analysis (LC-MS/MS).

A fast and simple method for residue analysis of the antibiotics classes of macrolides (erythromycin, azithromycin, tylosin, tilmicosin and spiramycin) and lincosamides (lincomycin and clindamycin) was developed and validated for cattle, swine and chicken muscle and for bovine milk. Sample preparation consists in a liquid-liquid extraction (LLE) with acetonitrile, followed by liquid chromatography-electrospray-tandem mass spectrometry analysis (LC-ESI-MS/MS), without the need of any additional clean-up steps. Chromatographic separation was achieved using a C18 column and a mobile phase composed by acidified acetonitrile and water.

High-throughput method for the determination of residues of β-lactam antibiotics in bovine milk by LC-MS/MS.

This study describes the development and validation procedures for scope extension of a method for the determination of β-lactam antibiotic residues (ampicillin, amoxicillin, penicillin G, penicillin V, oxacillin, cloxacillin, dicloxacillin, nafcillin, ceftiofur, cefquinome, cefoperazone, cephapirine, cefalexin and cephalonium) in bovine milk. Sample preparation was performed by liquid-liquid extraction (LLE) followed by two clean-up steps, including low temperature purification (LTP) and a solid phase dispersion clean-up. Extracts were analysed using a liquid chromatography-electrospray-tandem mass spectrometry system (LC-ESI-MS/MS).

Determination of sulfonamide antibiotics and metabolites in liver, muscle and kidney samples by pressurized liquid extraction or ultrasound-assisted extraction followed by liquid chromatography-quadrupole linear ion trap-tandem mass spectrometry (HPLC-QqLIT-MS/MS).

Sulfonamides are widely used in human and veterinary medicine. The presence of sulfonamides residues in food is an issue of great concern. Throughout the present work, a method for the targeted analysis of 16 sulfonamides and metabolites residue in liver of several species has been developed and validated.

Analytical quality assurance in veterinary drug residue analysis methods: matrix effects determination and monitoring for sulfonamides analysis.

In residue analysis of veterinary drugs in foodstuff, matrix effects are one of the most critical points. This work present a discuss considering approaches used to estimate, minimize and monitoring matrix effects in bioanalytical methods. Qualitative and quantitative methods for estimation of matrix effects such as post-column infusion, slopes ratios analysis, calibration curves (mathematical and statistical analysis) and control chart monitoring are discussed using real data.

Photocatalytic degradation of rosuvastatin: analytical studies and toxicity evaluations.

Photocatalytic degradation of rosuvastatin, which is a drug that has been used to reduce blood cholesterol levels, was studied in this work employing ZnO as catalyst. The experiments were carried out in a temperature-controlled batch reactor that was irradiated with UV light. Preliminary the effects of the photocatalyst loading, the initial pH and the initial rosuvastatin concentration were evaluated.

Structural elucidation of sulfaquinoxaline metabolism products and their occurrence in biological samples using high-resolution Orbitrap mass spectrometry.

Four previously unreported metabolism products of sulfaquinoxaline (SQX), a widely used veterinary medicine, were isolated and analyzed using liquid chromatography coupled to high-resolution Orbitrap mass spectrometry. Metabolites were structurally elucidated, and a fragmentation pathway was proposed. The combination of high-resolution MS(2) spectra, linear ion trap MS(2), in-source collision-induced dissociation (CID) fragmentation, and photolysis were used to analyze SQX and its metabolites.

Scope extension validation protocol: inclusion of analytes and matrices in an LC-MS/MS sulfonamide residues method.

Validation is a required process for analytical methods. However, scope extension, i.e.

A liquid-liquid extraction procedure followed by a low temperature purification step for the analysis of macrocyclic lactones in milk by liquid chromatography-tandem mass spectrometry and fluorescence detection.

In this work a method is proposed and demonstrated for the analysis of the macrocyclic lactones abamectin, doramectin, eprinomectin, ivermectin and moxidectin in bovine milk by liquid chromatography coupled to mass spectrometry (LC-MS/MS) and liquid chromatography with fluorescence detection (LC-FL). The method is based on liquid-liquid extraction followed by a low temperature purification (LLE-LTP) step. Moreover, the proposed method was validated according to the Commission Decision 2002/657/EC, using LC-MS/MS and LC-FL for confirmatory and quantitative analysis, respectively.

Trace level determination of beta-blockers in waste waters by highly selective molecularly imprinted polymers extraction followed by liquid chromatography-quadrupole-linear ion trap mass spectrometry.

This paper describes the development of an analytical methodology to determine eight beta-blockers in waste waters using molecularly imprinted polymers (MIPs) as extraction and pre-concentration material, followed by liquid chromatography-quadrupole-linear ion trap mass spectrometry (LC-QqLIT MS). The advantages offered by MIPs, in terms of selectivity and specificity, were compared with the most commonly polymeric materials used (the lipophilic-hydrophilic balanced Oasis HLB cartridges). Even though recoveries achieved with both sorbents were similar, ranging from 50 to 110% for sewage treatment plant (STP) effluent and 40-110 for STP influent, respectively, MIPs provided lower method detection limits than Oasis HLB, due to their specificity for target analytes and closely related analogues.

Rapid screening method for determination of PCDDs and PCDFs in fly ashes using GC-ion trap MS/MS based on cellular disruptor extraction.

Identification and quantification of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans in fly ashes from incinerator was carried out using capillary gas chromatography/tandem mass spectrometry (GC/MS/MS) with a low resolution ion trap mass spectrometer. Sample extraction was carried out in a cellular disruptor, in Soxhlet and in a conventional ultrasound for comparative purposes. Extraction with cellular disruptor was shown to be comparable to that obtained by the reference Soxhlet extraction, while low recoveries were observed with ultrasound.

Synthesis of zirconocene-based silica phases and evaluation in lindane and heptachlor epoxide adsorption/desorption.

Silica (350 m(2) g(-1)) was chemically modified with Cp2ZrCl2 and (nBuCp)2ZrCl2 by grafting. Hybrid silica bearing surface indene groups was synthesized by the sol-gel method, followed by metallation with ZrCl(4)2THF. The resulting phases were characterized by Rutherford backscattering spectrometry (RBS), 13C and 29Si magic angle spin nuclear magnetic resonance, X-ray photoelectron spectroscopy, and diffuse reflectance infrared Fourier transform spectroscopy.