Pub Date : 2022-12-22DOI: 10.30744/brjac.2179-3425.editorial.imaging
R. Augusti, V. Dressler
Over the past few years, chemical imaging technologies have experienced a dramatic increase in the number and diversity of applications. This is mainly due to the ability of such technologies to provide the spatial distribution of the various components of a sample. The spatial distribution of a specific chemical component in a given sample constitutes a precious piece of information. This is the base of several applications in different areas such as plant physiology, food safety, biomedical diagnosis, forensic analysis, pharmaceutical monitoring, cell analysis, and defense, among many others. Thus, this BrJAC special edition entitled “Chemical Imaging” intends to provide an overview of these new technologies and their use in the most diverse areas of knowledge. All the works presented in this special issue were carried out by research groups based in laboratories of universities in South America. Despite the enormous difficulties facing the development of science in the region, the manuscripts published in this special issue put in evidence the excellent quality of the science produced once they are at the frontier of knowledge.
{"title":"Novel Applications of Chemical Imaging, an Outstanding Technology","authors":"R. Augusti, V. Dressler","doi":"10.30744/brjac.2179-3425.editorial.imaging","DOIUrl":"https://doi.org/10.30744/brjac.2179-3425.editorial.imaging","url":null,"abstract":"Over the past few years, chemical imaging technologies have experienced a dramatic increase in the number and diversity of applications. This is mainly due to the ability of such technologies to provide the spatial distribution of the various components of a sample. The spatial distribution of a specific chemical component in a given sample constitutes a precious piece of information. This is the base of several applications in different areas such as plant physiology, food safety, biomedical diagnosis, forensic analysis, pharmaceutical monitoring, cell analysis, and defense, among many others. Thus, this BrJAC special edition entitled “Chemical Imaging” intends to provide an overview of these new technologies and their use in the most diverse areas of knowledge. All the works presented in this special issue were carried out by research groups based in laboratories of universities in South America. Despite the enormous difficulties facing the development of science in the region, the manuscripts published in this special issue put in evidence the excellent quality of the science produced once they are at the frontier of knowledge.","PeriodicalId":9115,"journal":{"name":"Brazilian Journal of Analytical Chemistry","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2022-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48490590","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-12-22DOI: 10.30744/brjac.2179-3425.interview.augusti
R. Augusti
Rodinei Augusti holds a degree in chemistry (1986), a master’s degree in chemistry (1990), and a doctorate in chemistry (1993), all from the University of Campinas (UNICAMP), SP, Brazil. Currently, he is a full professor in the Department of Chemistry, Institute of Exact Sciences, Federal University of Minas Gerais (UFMG), Belo Horizonte, MG, Brazil. He conducts research on the application of mass spectrometry in several areas, such as monitoring reactions of environmental interest and quality control of alcoholic beverages. Prof. Augusti is an advisor to the following journals: Rapid Communications in Mass Spectrometry, Journal of Mass Spectrometry, Analytical Chemistry, Inorganic Chemistry, Journal of the Brazilian Chemical Society, Analyst (London), Journal of the American Society for Mass Spectrometry, and Quimica Nova.
{"title":"Professor Rodinei Augusti, an enthusiast for the progress of chemistry in Brazil, kindly spoke to BrJAC","authors":"R. Augusti","doi":"10.30744/brjac.2179-3425.interview.augusti","DOIUrl":"https://doi.org/10.30744/brjac.2179-3425.interview.augusti","url":null,"abstract":"Rodinei Augusti holds a degree in chemistry (1986), a master’s degree in chemistry (1990), and a doctorate in chemistry (1993), all from the University of Campinas (UNICAMP), SP, Brazil. Currently, he is a full professor in the Department of Chemistry, Institute of Exact Sciences, Federal University of Minas Gerais (UFMG), Belo Horizonte, MG, Brazil. He conducts research on the application of mass spectrometry in several areas, such as monitoring reactions of environmental interest and quality control of alcoholic beverages. Prof. Augusti is an advisor to the following journals: Rapid Communications in Mass Spectrometry, Journal of Mass Spectrometry, Analytical Chemistry, Inorganic Chemistry, Journal of the Brazilian Chemical Society, Analyst (London), Journal of the American Society for Mass Spectrometry, and Quimica Nova.","PeriodicalId":9115,"journal":{"name":"Brazilian Journal of Analytical Chemistry","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2022-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45113559","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-12-22DOI: 10.30744/brjac.2179-3425.point-of-view-asussulini.n38
Alessandra Sussulini
Chemical images can be described as distribution maps that correlate the chemical information of an element or molecule, such as mass-to-charge ratio (m/z) or wavelength, with its intensity and/or concentration in a given sample. These images are usually obtained by mass spectrometry (MS) or optical spectroscopy techniques, where hundreds or thousands of spectra are initially acquired and dedicated image processing software is employed to construct and edit the final pictures, as well as selecting and annotating regions of interest in a sample, performing calibration procedures, etc. Mass spectrometry imaging (preferably abbreviated as MSI, to distinguish it from ion mobility spectrometry – IMS) is currently the most employed chemical imaging strategy, as can be noticed in the most recently published papers. Depending on the selected ionization technique, molecular or elemental images can be acquired. For molecular MSI, the classical matrix-assisted laser desorption/ionization (MALDI) is generally applied for imaging lipids, peptides and proteins, and the ambient ionization technique desorption electrospray ionization (DESI) is commonly applied for visualizing lipid distribution. In terms of elemental MSI, laser ablation inductively coupled plasma (LA-ICP) is undoubtedly the technique of choice, although nano-secondary ion mass spectrometry (nanoSIMS) can also be applied. Considering optical spectroscopy, the main techniques used nowadays are Raman and near-infrared radiation – NIR – spectroscopy for molecular imaging, and Synchrotron radiation X-ray fluorescence – SRXRF – and laser-induced breakdown spectroscopy – LIBS – for elemental imaging. Amongst these techniques, the best spatial resolutions are generally achieved by SRXRF (elemental imaging) and Raman spectroscopy (molecular imaging). Analytical chemistry advances in chemical imaging allow the acquisition of images with high spatial resolution, which is particularly interesting when studying specific regions or cell structures in a biological sample. For instance, in a Parkinson’s disease model, LA-ICP-MS images with good spatial resolution make the distinction of specific mouse brain regions possible and, consequently, the association of metal ion concentrations to each region,1 which is a relevant result considering micro-local metal speciation in neurodegenerative diseases. Nevertheless, there are some drawbacks in chemical imaging that demand further analytical development, such as the long analysis time and the lack of certified reference materials for quantitative analysis and method validation, as well as open-source software with advanced multivariate statistical analysis tools. Another obstacle to overcome concerns the integration of elemental and molecular imaging results. Since 2009, when one of the first review articles regarding the combination of these imaging approaches in a synergistic way was proposed by Becker and Jakubowski,2 until more recently described in reviews fro
{"title":"Chemical Imaging – Is an Image Always Worth a Thousand Spectra?","authors":"Alessandra Sussulini","doi":"10.30744/brjac.2179-3425.point-of-view-asussulini.n38","DOIUrl":"https://doi.org/10.30744/brjac.2179-3425.point-of-view-asussulini.n38","url":null,"abstract":"Chemical images can be described as distribution maps that correlate the chemical information of an element or molecule, such as mass-to-charge ratio (m/z) or wavelength, with its intensity and/or concentration in a given sample. These images are usually obtained by mass spectrometry (MS) or optical spectroscopy techniques, where hundreds or thousands of spectra are initially acquired and dedicated image processing software is employed to construct and edit the final pictures, as well as selecting and annotating regions of interest in a sample, performing calibration procedures, etc. Mass spectrometry imaging (preferably abbreviated as MSI, to distinguish it from ion mobility spectrometry – IMS) is currently the most employed chemical imaging strategy, as can be noticed in the most recently published papers. Depending on the selected ionization technique, molecular or elemental images can be acquired. For molecular MSI, the classical matrix-assisted laser desorption/ionization (MALDI) is generally applied for imaging lipids, peptides and proteins, and the ambient ionization technique desorption electrospray ionization (DESI) is commonly applied for visualizing lipid distribution. In terms of elemental MSI, laser ablation inductively coupled plasma (LA-ICP) is undoubtedly the technique of choice, although nano-secondary ion mass spectrometry (nanoSIMS) can also be applied. Considering optical spectroscopy, the main techniques used nowadays are Raman and near-infrared radiation – NIR – spectroscopy for molecular imaging, and Synchrotron radiation X-ray fluorescence – SRXRF – and laser-induced breakdown spectroscopy – LIBS – for elemental imaging. Amongst these techniques, the best spatial resolutions are generally achieved by SRXRF (elemental imaging) and Raman spectroscopy (molecular imaging). Analytical chemistry advances in chemical imaging allow the acquisition of images with high spatial resolution, which is particularly interesting when studying specific regions or cell structures in a biological sample. For instance, in a Parkinson’s disease model, LA-ICP-MS images with good spatial resolution make the distinction of specific mouse brain regions possible and, consequently, the association of metal ion concentrations to each region,1 which is a relevant result considering micro-local metal speciation in neurodegenerative diseases. Nevertheless, there are some drawbacks in chemical imaging that demand further analytical development, such as the long analysis time and the lack of certified reference materials for quantitative analysis and method validation, as well as open-source software with advanced multivariate statistical analysis tools. Another obstacle to overcome concerns the integration of elemental and molecular imaging results. Since 2009, when one of the first review articles regarding the combination of these imaging approaches in a synergistic way was proposed by Becker and Jakubowski,2 until more recently described in reviews fro","PeriodicalId":9115,"journal":{"name":"Brazilian Journal of Analytical Chemistry","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2022-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42047307","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-11-30DOI: 10.30744/brjac.2179-3425.ar-88-2022
Wilson do Nascimento Filho, M. Cidade, F. Panero, O. Smiderle
In this article, digital image processing and analysis (DIPA) combined with chemometric methods, principal component analysis (PCA) and hierarchical cluster analysis (HCA) were used to discriminate sesame seeds through their digitized images. For this purpose, four groups of seeds were used: BRS Anahí and BRS Seda cultivars, a lineage and a commercial sample. The images were scanned using an HP officejet 7610 scanner and, for extraction of the red-green-blue channels and colorimetric profile, the ImageJ software was used. The DIPA combined with chemometric methods allowed us to discriminate the four groups of sesame seeds efficiently, and a minimum accumulated variance of 89.03% of the total variance was obtained. The trends observed via the PCA were confirmed through the dendrograms obtained using the HCA. The results achieved in this work indicate that the proposed methodology can be a simple analytical alternative for the non-destructive phenotypic discrimination of seeds, with their color as an attribute.
{"title":"Application of Digital Imaging Allied to Chemometrics in the Use of Non-destructive Phenotyping of Sesame Seeds","authors":"Wilson do Nascimento Filho, M. Cidade, F. Panero, O. Smiderle","doi":"10.30744/brjac.2179-3425.ar-88-2022","DOIUrl":"https://doi.org/10.30744/brjac.2179-3425.ar-88-2022","url":null,"abstract":"In this article, digital image processing and analysis (DIPA) combined with chemometric methods, principal component analysis (PCA) and hierarchical cluster analysis (HCA) were used to discriminate sesame seeds through their digitized images. For this purpose, four groups of seeds were used: BRS Anahí and BRS Seda cultivars, a lineage and a commercial sample. The images were scanned using an HP officejet 7610 scanner and, for extraction of the red-green-blue channels and colorimetric profile, the ImageJ software was used. The DIPA combined with chemometric methods allowed us to discriminate the four groups of sesame seeds efficiently, and a minimum accumulated variance of 89.03% of the total variance was obtained. The trends observed via the PCA were confirmed through the dendrograms obtained using the HCA. The results achieved in this work indicate that the proposed methodology can be a simple analytical alternative for the non-destructive phenotypic discrimination of seeds, with their color as an attribute.","PeriodicalId":9115,"journal":{"name":"Brazilian Journal of Analytical Chemistry","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2022-11-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44862043","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-11-18DOI: 10.30744/brjac.2179-3425.ar-68-2022
Antonio Nichele, João dos Santos
Latex (acrylic resin) produced by emulsion polymerization usually contains variable amounts of residual volatiles (free monomers). Depending on the chemical nature of the monomer, even if these compounds are present in smaller quantities than other volatiles, they can make the latex exude a strong odor and offer toxicity, as with ethyl acrylate, which may make it unfeasible for the consumer to apply the latex. In the present study, a quantitative chromatographic method using gas chromatography with a flame ionization detector (GC-FID) for industrial laboratory determination was investigated. Free ethyl acrylate monomer at a concentration level of 0.010% w/w in a resin-type latex was determined. This method showed selectivity for ethyl acrylate versus other volatiles in the sample, linearity with a coefficient of determination greater than 0.99, limits of detection and quantification of 0.001 and 0.003% w/w, respectively, accuracy and precision with recoveries above 85% and coefficients of variation below 10%. The robustness parameter demonstrated with a Pareto chart shows that the chromatographic parameters of the split ratio, injection volume and temperature impact the method performance.
{"title":"Analytical Method for Residual Monomer Ethyl Acrylate Determination in Commercial Latex Resin using Gas Chromatography with Flame Ionization Detection","authors":"Antonio Nichele, João dos Santos","doi":"10.30744/brjac.2179-3425.ar-68-2022","DOIUrl":"https://doi.org/10.30744/brjac.2179-3425.ar-68-2022","url":null,"abstract":"Latex (acrylic resin) produced by emulsion polymerization usually contains variable amounts of residual volatiles (free monomers). Depending on the chemical nature of the monomer, even if these compounds are present in smaller quantities than other volatiles, they can make the latex exude a strong odor and offer toxicity, as with ethyl acrylate, which may make it unfeasible for the consumer to apply the latex. In the present study, a quantitative chromatographic method using gas chromatography with a flame ionization detector (GC-FID) for industrial laboratory determination was investigated. Free ethyl acrylate monomer at a concentration level of 0.010% w/w in a resin-type latex was determined. This method showed selectivity for ethyl acrylate versus other volatiles in the sample, linearity with a coefficient of determination greater than 0.99, limits of detection and quantification of 0.001 and 0.003% w/w, respectively, accuracy and precision with recoveries above 85% and coefficients of variation below 10%. The robustness parameter demonstrated with a Pareto chart shows that the chromatographic parameters of the split ratio, injection volume and temperature impact the method performance.","PeriodicalId":9115,"journal":{"name":"Brazilian Journal of Analytical Chemistry","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2022-11-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43899941","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-11-11DOI: 10.30744/brjac.2179-3425.ar-59-2022
Vânia Teles, P. Vendramini, R. Augusti, L. Costa
Basil samples (Ocimum basilicum Lameaceae) were exposed to cadmium and analyzed on porous PTFE membrane, and TLC plate substrates by desorption electrospray ionization mass spectrometry imaging (DESI-MSI) for amino acids and sugars identification. The TLC plate was the best substrate for analysis of the basil leaves, with high-definition images, small extract scattering, low mass deviations, and excellent reliability in the spatial distribution of the analytes. DESI-MSI analysis identified 13 images of ions putatively annotated as amino acids and sugars with high accuracy (mass deviation between -1.97 to 1.42 ppm) in contaminated and non-contaminated leaves. In general, the amino acids and sugars (proline, histidine, glutamine, arginine, homoarginine, theanine, hexose sugars, and disaccharides) accumulated preferably in basil leaves as a defense mechanism against exposure to cadmium. Asparagine, tyrosine, glutamic acid, and phenylalanine were inhibited when exposed to the toxic element. The images obtained in this study demonstrated the spatial distribution and accumulation of amino acids and sugars in basil leaves as a response to cadmium contamination, confirming that DESI-MSI is a valuable and promising tool for metabolomics studies in plants exposed to toxic metals.
{"title":"Application of Mass Spectrometry Imaging in Evaluating the Spatial Distribution of Aminoacids and Sugars in Basil Leaves upon Long-Time Exposure to Cadmium","authors":"Vânia Teles, P. Vendramini, R. Augusti, L. Costa","doi":"10.30744/brjac.2179-3425.ar-59-2022","DOIUrl":"https://doi.org/10.30744/brjac.2179-3425.ar-59-2022","url":null,"abstract":"Basil samples (Ocimum basilicum Lameaceae) were exposed to cadmium and analyzed on porous PTFE membrane, and TLC plate substrates by desorption electrospray ionization mass spectrometry imaging (DESI-MSI) for amino acids and sugars identification. The TLC plate was the best substrate for analysis of the basil leaves, with high-definition images, small extract scattering, low mass deviations, and excellent reliability in the spatial distribution of the analytes. DESI-MSI analysis identified 13 images of ions putatively annotated as amino acids and sugars with high accuracy (mass deviation between -1.97 to 1.42 ppm) in contaminated and non-contaminated leaves. In general, the amino acids and sugars (proline, histidine, glutamine, arginine, homoarginine, theanine, hexose sugars, and disaccharides) accumulated preferably in basil leaves as a defense mechanism against exposure to cadmium. Asparagine, tyrosine, glutamic acid, and phenylalanine were inhibited when exposed to the toxic element. The images obtained in this study demonstrated the spatial distribution and accumulation of amino acids and sugars in basil leaves as a response to cadmium contamination, confirming that DESI-MSI is a valuable and promising tool for metabolomics studies in plants exposed to toxic metals.","PeriodicalId":9115,"journal":{"name":"Brazilian Journal of Analytical Chemistry","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2022-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45070376","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-10-26DOI: 10.30744/brjac.2179-3425.ar-55-2022
C. Pereira, V. Neves, Graciela Hidrich, H. Faccin, D. Pozebon, V. Dressler
Rice is a food consumed worldwide and there is a grown concern about its nutritional value, as well as the concentration of contaminant elements. Laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) was employed in the present work for determination and imaging of Mg, Mn, Cu, Co, Fe, Zn, As, Sr, Sb, Ba and Pb in grains of white, parboiled, and whole (brown) rice. The elements quantification was achieved by using external calibration whereas filter paper discs served as support for the reference solutions and matrix matching. Accuracy was ensured by analysing two certified reference materials (CRMs) pressed into pellets. Investigations were carried out to evaluate the distribution of the elements on the surface and external layers of the grains. For that purpose, the surface of rice grains fixed on a glass support was ablated line-by-line and the ablation repeated three times. The images generated from laser ablation revealed that the investigated elements were not homogeneously distributed in the analysed parts of the grains. Except for Pb, the investigated elements were detected in three layers of the rice grains, but it was observed that the elements concentrations decreased from the surface to more internal layers. Lead was detected only in the first layer of white and whole rice and in the first and second layers of parboiled rice.
{"title":"Imaging of Elements Distribution in Rice by Laser Ablation Inductively Coupled Plasma Mass Spectrometry","authors":"C. Pereira, V. Neves, Graciela Hidrich, H. Faccin, D. Pozebon, V. Dressler","doi":"10.30744/brjac.2179-3425.ar-55-2022","DOIUrl":"https://doi.org/10.30744/brjac.2179-3425.ar-55-2022","url":null,"abstract":"Rice is a food consumed worldwide and there is a grown concern about its nutritional value, as well as the concentration of contaminant elements. Laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) was employed in the present work for determination and imaging of Mg, Mn, Cu, Co, Fe, Zn, As, Sr, Sb, Ba and Pb in grains of white, parboiled, and whole (brown) rice. The elements quantification was achieved by using external calibration whereas filter paper discs served as support for the reference solutions and matrix matching. Accuracy was ensured by analysing two certified reference materials (CRMs) pressed into pellets. Investigations were carried out to evaluate the distribution of the elements on the surface and external layers of the grains. For that purpose, the surface of rice grains fixed on a glass support was ablated line-by-line and the ablation repeated three times. The images generated from laser ablation revealed that the investigated elements were not homogeneously distributed in the analysed parts of the grains. Except for Pb, the investigated elements were detected in three layers of the rice grains, but it was observed that the elements concentrations decreased from the surface to more internal layers. Lead was detected only in the first layer of white and whole rice and in the first and second layers of parboiled rice.","PeriodicalId":9115,"journal":{"name":"Brazilian Journal of Analytical Chemistry","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2022-10-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45294032","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-10-13DOI: 10.30744/brjac.2179-3425.ar-43-2022
M. Fernandes, A. Camelo, P. Vendramini, M. Brocchi, Ana Simionato
The inappropriate and excessive use of antibiotics for the treatment of bacterial infections has led to the increasing presence of resistant and multidrug-resistant bacteria both in hospital settings and in the community. Thus, understanding the metabolism of resistant bacteria is extremely important to combat them more efficiently. In this scenario, mass spectrometry imaging (MSI) is considered a promising technique for understanding the resistant characteristics of such bacteria and how they can potentially be treated. This process consists of the identification of different ions on the surface of the colonies and the identification of potential metabolites that characterize antibiotic resistance, upon comparison with susceptible bacteria of the same species. This work presents matrix-assisted laser desorption ionization-mass spectrometry imaging (MALDI-MSI) study of colonies of Methicillin-resistant Staphylococcus aureus, as a proof of concept of the technique for obtaining images of bacteria colonies. Images of methicillin-resistant and susceptible colonies of Staphylococcus aureus were obtained by a sublimation process to apply the MALDI matrix on the samples followed by MALDI-MSI analysis. Seventeen (17) potential metabolites were identified and spatially localized, such as N,N-dihydroxy-L-valine, 2-(4-Methylphenyl)ethylamine, 3,4-Dihydroxy-L-phenylalanine, 2-Methyl-hexanoic acid, threonine, Arginine, Aureusimine and Glycyl-D-asparagine. Thus, this study reinforces the potential of MALDI-MSI for identification of metabolites synthesized by different strains of Staphylococcus aureus bacteria.
{"title":"Exploring Bacterial Resistant Metabolism by Matrix-Assisted Laser Desorption Ionization-Mass Spectrometry Imaging","authors":"M. Fernandes, A. Camelo, P. Vendramini, M. Brocchi, Ana Simionato","doi":"10.30744/brjac.2179-3425.ar-43-2022","DOIUrl":"https://doi.org/10.30744/brjac.2179-3425.ar-43-2022","url":null,"abstract":"The inappropriate and excessive use of antibiotics for the treatment of bacterial infections has led to the increasing presence of resistant and multidrug-resistant bacteria both in hospital settings and in the community. Thus, understanding the metabolism of resistant bacteria is extremely important to combat them more efficiently. In this scenario, mass spectrometry imaging (MSI) is considered a promising technique for understanding the resistant characteristics of such bacteria and how they can potentially be treated. This process consists of the identification of different ions on the surface of the colonies and the identification of potential metabolites that characterize antibiotic resistance, upon comparison with susceptible bacteria of the same species. This work presents matrix-assisted laser desorption ionization-mass spectrometry imaging (MALDI-MSI) study of colonies of Methicillin-resistant Staphylococcus aureus, as a proof of concept of the technique for obtaining images of bacteria colonies. Images of methicillin-resistant and susceptible colonies of Staphylococcus aureus were obtained by a sublimation process to apply the MALDI matrix on the samples followed by MALDI-MSI analysis. Seventeen (17) potential metabolites were identified and spatially localized, such as N,N-dihydroxy-L-valine, 2-(4-Methylphenyl)ethylamine, 3,4-Dihydroxy-L-phenylalanine, 2-Methyl-hexanoic acid, threonine, Arginine, Aureusimine and Glycyl-D-asparagine. Thus, this study reinforces the potential of MALDI-MSI for identification of metabolites synthesized by different strains of Staphylococcus aureus bacteria.","PeriodicalId":9115,"journal":{"name":"Brazilian Journal of Analytical Chemistry","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2022-10-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44041954","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-10-06DOI: 10.30744/brjac.2179-3425.ar-46-2022
Fabiana dos Santos, F. Monedeiro, Jesus Velho, Sergio de Souza, E. D. de Campos, B. D. de Martinis
Cocaine is an illicit drug commonly found by law enforcement in seizures around the world. This paper describes a rare case of cocaine trafficking in asphaltic material, possibly in the form of cocaine hydrochloride. The material was found and seized in barrels during an operation conducted by the Brazilian Federal Police. The sample was initially extracted and resulted negative for cocaine via Scott’s Test, but further screening by gas chromatography coupled with mass spectrometry (GC-MS) confirmed the presence of cocaine. Afterwards, samples were subjected to quantitative GC-MS analysis. The concentrations of cocaine ranged from 0.11 to 1.53 ng/10 mg in the extracts of precipitate material found in the barrels. Considering that extraction efficiency was around 57.44%, it is estimated that 1.07 – 15.34% of barrel’s sediment weight was constituted by cocaine.
{"title":"Cocaine Trafficking in Asphalt Material: An Unusual Report of Cocaine in Seized Drugs","authors":"Fabiana dos Santos, F. Monedeiro, Jesus Velho, Sergio de Souza, E. D. de Campos, B. D. de Martinis","doi":"10.30744/brjac.2179-3425.ar-46-2022","DOIUrl":"https://doi.org/10.30744/brjac.2179-3425.ar-46-2022","url":null,"abstract":"Cocaine is an illicit drug commonly found by law enforcement in seizures around the world. This paper describes a rare case of cocaine trafficking in asphaltic material, possibly in the form of cocaine hydrochloride. The material was found and seized in barrels during an operation conducted by the Brazilian Federal Police. The sample was initially extracted and resulted negative for cocaine via Scott’s Test, but further screening by gas chromatography coupled with mass spectrometry (GC-MS) confirmed the presence of cocaine. Afterwards, samples were subjected to quantitative GC-MS analysis. The concentrations of cocaine ranged from 0.11 to 1.53 ng/10 mg in the extracts of precipitate material found in the barrels. Considering that extraction efficiency was around 57.44%, it is estimated that 1.07 – 15.34% of barrel’s sediment weight was constituted by cocaine.","PeriodicalId":9115,"journal":{"name":"Brazilian Journal of Analytical Chemistry","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2022-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47835484","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-10-06DOI: 10.30744/brjac.2179-3425.rv-60-2022
C. D. de Paula
In this review, the use of mass spectrometry imaging (MSI) was addressed, focusing on the study of plant tissues, especially vegetables. The discussion about the taxonomy of plant tissues and organs is commonly based on immunohistochemistry and immunofluorescence essays. Although these techniques are quite appropriate for the structural study of tissues and organs, their low specificity limits their use to the identification of only a few compounds. Mass spectrometry (MS) hyphenated with chromatography techniques are capable to identifying a wide variety of compounds in plant tissue matrices, but these analyzes do not provide spatial information of the sample. MSI techniques stands out in this scenario due their capacity to provide information about both composition and spatial distribution of different biological matrices in the in the same approach. The potential of the MSI techniques to provide information about primary and secondary metabolites in plant tissue, as well as chemical responses associated with external stimuli, can be demonstrated through published works that employ different ionization sources such as SIMS, MALDI and DESI and their modifications.
{"title":"Mass Spectrometry Imaging for Vegetables: A Review","authors":"C. D. de Paula","doi":"10.30744/brjac.2179-3425.rv-60-2022","DOIUrl":"https://doi.org/10.30744/brjac.2179-3425.rv-60-2022","url":null,"abstract":"In this review, the use of mass spectrometry imaging (MSI) was addressed, focusing on the study of plant tissues, especially vegetables. The discussion about the taxonomy of plant tissues and organs is commonly based on immunohistochemistry and immunofluorescence essays. Although these techniques are quite appropriate for the structural study of tissues and organs, their low specificity limits their use to the identification of only a few compounds. Mass spectrometry (MS) hyphenated with chromatography techniques are capable to identifying a wide variety of compounds in plant tissue matrices, but these analyzes do not provide spatial information of the sample. MSI techniques stands out in this scenario due their capacity to provide information about both composition and spatial distribution of different biological matrices in the in the same approach. The potential of the MSI techniques to provide information about primary and secondary metabolites in plant tissue, as well as chemical responses associated with external stimuli, can be demonstrated through published works that employ different ionization sources such as SIMS, MALDI and DESI and their modifications.","PeriodicalId":9115,"journal":{"name":"Brazilian Journal of Analytical Chemistry","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2022-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47840506","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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