Exploring matrix effects in liquid chromatography–tandem mass spectrometry determination of pesticide residues in tropical fruits

Tropical fruits are being increasingly consumed around the world because of their appreciated characteristics, particularly their high nutritional value and distinctive taste, which are different from those of traditional fruits. Owing to their introduction into international markets it is necessary to have a reliable analytical methodology available for the sensitive determination of pesticide residues in order to monitor the compliance of maximum residue limits (MRLs). From an analytical point of view, tropical fruits have generally been far less studied than other fruits frequently consumed in the European Union or USA, which are among the most important markets. In this work, LC–MS/MS-based methodology using a triple quadrupole analyzer was developed for the multi-residue determination of selected pesticides and metabolites in tropical fruits, which were selected among the most popular in Colombia, one of the most important suppliers of tropical fruits around the world. After selection of a QuEChERS (Quick, Easy, Cheap, Effective, Rugged, and Safe)-based sample treatment, the study focused on the evaluation of matrix effects, in order to find a simple way for their correction. Twelve different food matrices were selected to perform this study: the seven Colombian tropical fruits of highest value for domestic and international markets (uchuva, tamarillo, granadilla, gulupa, maracuya, papaya, and pithaya), and five more matrices highly consumed in Colombia (lulo, carambolo, feijoa, mangostan, and guayaba). Twenty compounds, including pesticides widely applied in tropical fruits pest control and several metabolites considered in residue definition, were used as model compounds in this work. Correction factors were used on the basis of calibration graphs obtained with standards in solvent and in matrix, and their usefulness was supported by validation of the method in all the matrices tested at 0.01 and 0.1 mg/kg. The analysis of real-world samples revealed the presence of several target compounds that were identified by the acquisition of two MS/MS transitions, and by ion intensity ratio and retention time agreement.Generalitat Valenciana (Research Group of Excellence Prometeo 2009/ 054 and Prometeo II 2014/023; Collaborative Research on Environment and Food-Safety, ISIC/2012/016

Removal of a mixture of veterinary medicinal products by adsorption onto a Scenedesmus almeriensis microalgae-bacteria consortium

Producción CientíficaThe adsorption of the veterinary medicinal products (VMP) tetracycline (TET), ciprofloxacin (CIP), sulfadiazine (SDZ) and sulfamethoxazole (SMX) onto a dried Scenedesmus almeriensis microalgae-bacteria consortium was studied at several equilibrium concentrations (20 to 1000 μg/L). Scanning electron microscopy (SEM) and Fourier-transform infrared spectroscopy (FTIR) analysis were performed to investigate the surface morphology of the microalgae and to identify the effect of the antibiotics´ functional groups on the surface of the consortium of S. almeriensis and bacteria. Ultra-high performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS) was used to determine the feasibility of this consortium for the removal of antibiotics via biosorption. Freundlich and Langmuir adsorption models were used for the mathematical description of the adsorption equilibrium. Pseudo-first order and pseudo-second order kinetic models were applied to fit the biosorption experimental data. Relative antibiotic removal was higher at low equilibrium concentrations. In the range of the initial VMP concentration studied, ciprofloxacin and tetracycline exhibited the highest removal efficiency of 43–100% and 75–82%, respectively. Likewise, ciprofloxacin and tetraciclyne presented the highest adsorption rates of 0.11–26.66 and 1.78–27.09 mg·μg−1·h−1, respectively. This study revealed that the S. almeriensis-bacteria consortium has a high biosorption power and proved that biosorption is an important mechanism in the removal of ciprofloxacin and tetraciclyne using a microalgae-based water treatment process. However, sulfadiazine and sulfamethoxazole removals did not exceed 32%.Junta de Castilla y León (grants UIC 071, CLU 2017-09 and VA080G18)Ministerio de Ciencia, Innovación y Universidades (grant CTQ2017-84006-C3-1-R

Bogotá River anthropogenic contamination alters microbial communities and promotes spread of antibiotic resistance genes

The increase in antibiotic resistant bacteria has raised global concern regarding the future effectiveness of antibiotics. Human activities that influence microbial communities and environmental resistomes can generate additional risks to human health. In this work, we characterized aquatic microbial communities and their resistomes in samples collected at three sites along the Bogotá River and from wastewaters at three city hospitals, and investigated community profiles and antibiotic resistance genes (ARGs) as a function of anthropogenic contamination. The presence of antibiotics and other commonly used drugs increased in locations highly impacted by human activities, while the diverse microbial communities varied among sites and sampling times, separating upstream river samples from more contaminated hospital and river samples. Clinically relevant antibiotic resistant pathogens and ARGs were more abundant in contaminated water samples. Tracking of resistant determinants to upstream river waters and city sources suggested that human activities foster the spread of ARGs, some of which were co-localized with mobile genetic elements in assembled metagenomic contigs. Human contamination of this water ecosystem changed both community structure and environmental resistomes that can pose a risk to human health

A case study on pharmaceutical residues and antimicrobial resistance genes in Costa Rican rivers: A possible route of contamination for feline and other species

In this investigation, the presence of antibiotics and pharmaceuticals in Costa Rican surface waters, specifically in regions near feline habitats, was examined. The study revealed that 47% of the water samples contained detectable traces of at least one antibiotic. Ciprofloxacin and norfloxacin were the most frequently detected compounds, each with a detection rate of 27%. Other antibiotics, such as erythromycin, roxithromycin, and trimethoprim, were also found but at lower frequencies, around 14%. Notably, all antibiotic concentrations remained below 10 ng/L, with ciprofloxacin, norfloxacin, and erythromycin showing the highest concentrations. Furthermore, the investigation revealed the presence of non-antibiotic pharmaceutical residues in the water samples, typically at concentrations below 64 ng/L. Tramadol was the most frequently detected compound, present in 18% of the samples. The highest concentrations were observed for acetaminophen and tramadol, measuring 64 and 10 ng/L, respectively. Comparing these findings with studies conducted in treated wastewater and urban rivers, it became evident that the concentrations of antibiotics and pharmaceuticals were notably lower in this study. While previous research reported higher values, the limited number of studies conducted in protected areas raises concerns about the potential environmental impact on biodiversity. In summary, these results emphasize the importance of monitoring pharmaceutical residues and antimicrobial resistance genes ARGs in vulnerable ecosystems, especially those in close proximity to feline habitats in Costa Rica. Additionally, the study delved into the detection of (ARGs). All tested water samples were positive for at least one ARG, with the blaTEM gene being the most prevalent at 82%, followed by tetS at 64% and qnrB at 23%. Moreover, this research shed light on the complexity of evaluating ARGs in environmental samples, as their presence does not necessarily indicate their expression. It also highlighted the potential for co-selection and co-regulation of ARGs, showcasing the intricate behaviors of these genes in aquatic environments.Fondo de Educación Superior Estatal del Consejo Nacional de Rectores de Costa Rica (CONARE)8.3 Q1 JCR 20221.635 Q1 SJR 2022No data IDR 2022UE