Pub Date : 2023-03-17DOI: 10.30744/brjac.2179-3425.ar-108-2022
Jessica Selva, M. Bertotti
The fabrication and long-term application of a pH Au microelectrode based on an iridium oxide film are reported. A uniform iridium oxide film with a typical thickness of around 1 µm was coated on the microelectrode surface through a 2-step procedure involving electrodeposition at constant potential and further continuous voltammetric scans. A super-Nernstian slope of around 77 mV per pH unit was found from open circuit potential measurements in a broad pH range (2 to 10) in 0.01 mol L-1 phosphate buffer. It was demonstrated experimentally that the short-term pH precision of the IrOx sensor is ± 0.1 pH. The response stability was maintained in the physiological pH range, and the sensor exhibited excellent reproducibility, long-term stability, and a short response time of < 10 s. The results reported in this work confirmed that iridium oxide showed very promising pH sensing performance and can serve as an electrode material for detecting local pH changes in samples of increased complexity, such as juice fruits, culture medium, synthetic urine, and blood.
{"title":"Iridium Oxides Based Potentiometric Sensor for pH Monitoring in Biological Samples","authors":"Jessica Selva, M. Bertotti","doi":"10.30744/brjac.2179-3425.ar-108-2022","DOIUrl":"https://doi.org/10.30744/brjac.2179-3425.ar-108-2022","url":null,"abstract":"The fabrication and long-term application of a pH Au microelectrode based on an iridium oxide film are reported. A uniform iridium oxide film with a typical thickness of around 1 µm was coated on the microelectrode surface through a 2-step procedure involving electrodeposition at constant potential and further continuous voltammetric scans. A super-Nernstian slope of around 77 mV per pH unit was found from open circuit potential measurements in a broad pH range (2 to 10) in 0.01 mol L-1 phosphate buffer. It was demonstrated experimentally that the short-term pH precision of the IrOx sensor is ± 0.1 pH. The response stability was maintained in the physiological pH range, and the sensor exhibited excellent reproducibility, long-term stability, and a short response time of < 10 s. The results reported in this work confirmed that iridium oxide showed very promising pH sensing performance and can serve as an electrode material for detecting local pH changes in samples of increased complexity, such as juice fruits, culture medium, synthetic urine, and blood.","PeriodicalId":9115,"journal":{"name":"Brazilian Journal of Analytical Chemistry","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2023-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49333634","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 : 2023-03-10DOI: 10.30744/brjac.2179-3425.letter-almeida-cass
Fernando Almeida, Q. Cass
Affinity selection mass spectrometry (AS-MS) has been shown to be a powerful tool for identifying bioactive molecules in synthetic and/or natural libraries. The selection provided by the formation of the target-ligand complex allows the identification of hits irrespective of their functional effect. Moreover, it precludes the use of label, since the binders are identified by their exact mass.1 The binders are determined by an affinity or index ratio calculated through control assays. The target protein can be used in solution or immobilized in a solid support (Figure 1). Both approaches have pros and cons. Unlike most conventional high-throughput screening assays, AS-MS has fewer or no limitations when it comes to target selection. It is important, however, to understand the implications of choosing membrane proteins as targets. Membrane proteins correspond to 42% of all drug targets listed in DrugBank. Moreover, they are likely to be selected as protein targets due to their participation in many disease pathways, acting as ion channels, molecular transporters, solute carriers, receptors, and anchors. One of the bottlenecks in working with membrane proteins comes from the need to use a detergent for solubilization, folding, and structure maintenance. Detergents are usually used above the critical micelle concentration, which can lead to empty micelles and thus to false positive results, caused by nonspecific interactions with the detergent micelles.8 Interference in the ionization of the binders also needs to be examined.
{"title":"Affinity Selection Mass Spectrometry (AS-MS) as a Tool for Prospecting Target Ligands","authors":"Fernando Almeida, Q. Cass","doi":"10.30744/brjac.2179-3425.letter-almeida-cass","DOIUrl":"https://doi.org/10.30744/brjac.2179-3425.letter-almeida-cass","url":null,"abstract":"Affinity selection mass spectrometry (AS-MS) has been shown to be a powerful tool for identifying bioactive molecules in synthetic and/or natural libraries. The selection provided by the formation of the target-ligand complex allows the identification of hits irrespective of their functional effect. Moreover, it precludes the use of label, since the binders are identified by their exact mass.1 The binders are determined by an affinity or index ratio calculated through control assays. The target protein can be used in solution or immobilized in a solid support (Figure 1). Both approaches have pros and cons. Unlike most conventional high-throughput screening assays, AS-MS has fewer or no limitations when it comes to target selection. It is important, however, to understand the implications of choosing membrane proteins as targets. Membrane proteins correspond to 42% of all drug targets listed in DrugBank. Moreover, they are likely to be selected as protein targets due to their participation in many disease pathways, acting as ion channels, molecular transporters, solute carriers, receptors, and anchors. One of the bottlenecks in working with membrane proteins comes from the need to use a detergent for solubilization, folding, and structure maintenance. Detergents are usually used above the critical micelle concentration, which can lead to empty micelles and thus to false positive results, caused by nonspecific interactions with the detergent micelles.8 Interference in the ionization of the binders also needs to be examined.","PeriodicalId":9115,"journal":{"name":"Brazilian Journal of Analytical Chemistry","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2023-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69580378","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 : 2023-03-10DOI: 10.30744/brjac.2179-3425.point-of-view-mvbzanoni
M. Zanoni
How to artificially mimic a natural process as important and complex as photosynthesis in plants? Apart from being essential for life on our planet, the phenomenon of artificial photosynthesis is intriguing because it provides an incredible ability to capture light and energy, subsequently converting it into chemical energy with high-quantum efficiency. As a consequence of increasing economic and environmental interest, research on artificial photosynthesis has increased; an exponential growth has been seen from the 21st century onwards, with mastery of the phenomenon’s mechanisms being a major challenge to stimulate further development of the subject. Since the 20th century, there have been great expectations regarding further advancing the process of artificial photosynthesis due to the clear recognition of its importance for humanity. With increasing problems in the context of climate change and energy shortages, the possibility of using the core concepts of photosynthesis to contribute to advancing our knowledge on the generation of clean energy from water splitting and hydrogen production, and the recycling of CO2 into hydrocarbon compounds and/or fuels with ample added value has become increasingly important.
{"title":"Artificial Photosynthesis Technology: Is it Possible?","authors":"M. Zanoni","doi":"10.30744/brjac.2179-3425.point-of-view-mvbzanoni","DOIUrl":"https://doi.org/10.30744/brjac.2179-3425.point-of-view-mvbzanoni","url":null,"abstract":"How to artificially mimic a natural process as important and complex as photosynthesis in plants? Apart from being essential for life on our planet, the phenomenon of artificial photosynthesis is intriguing because it provides an incredible ability to capture light and energy, subsequently converting it into chemical energy with high-quantum efficiency. As a consequence of increasing economic and environmental interest, research on artificial photosynthesis has increased; an exponential growth has been seen from the 21st century onwards, with mastery of the phenomenon’s mechanisms being a major challenge to stimulate further development of the subject. Since the 20th century, there have been great expectations regarding further advancing the process of artificial photosynthesis due to the clear recognition of its importance for humanity. With increasing problems in the context of climate change and energy shortages, the possibility of using the core concepts of photosynthesis to contribute to advancing our knowledge on the generation of clean energy from water splitting and hydrogen production, and the recycling of CO2 into hydrocarbon compounds and/or fuels with ample added value has become increasingly important.","PeriodicalId":9115,"journal":{"name":"Brazilian Journal of Analytical Chemistry","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2023-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45029722","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 : 2023-03-02DOI: 10.30744/brjac.2179-3425.tn-80-2022
P. Onofre, D. Barros, Gabriela Silva, F. Fonseca, P. Rosa, M. Pedreira, M. Peterlini
Vancomycin hydrochloride is a tricyclic glycopeptide that contains amino acids and sugars. This substance is indicated to treat serious infections caused by Gram-positive bacteria by intravenous infusion. The objective of this study was to develop and validate an analytical methodology by high performance liquid chromatography with ultraviolet detection (HPLC-UV) to determine vancomycin hydrochloride content by assessing the parameters of selectivity, linearity, working range, matrix effect, robustness, precision, and accuracy. The sample used was vancomycin hydrochloride in a vial and analyzes were carried out on HPLC-UV system, with C18 reverse-phase column at 30 °C, pH=4 and diode-array detection (220 nm). The mobile phase was composed of acetonitrile and monobasic ammonium phosphate buffer (8:92 v/v), 1 mL min-1 flow, injection volume of 20 μL and 15 minute of run time. The method has been shown to be selective, free from mobile phase interference, diluent and other substances on vancomycin hydrochloride retention time; the method is linear in the range between 25 and 175 µg mL-1; matrix effect showed parallelism between the lines, thus indicating the absence of interference of the matrix constituents in analysis of the compound of interest; the method was robust with drug variations proportional to the deliberate changes caused by the change in the flow rate of the mobile phase and in the column temperature; the method showed accuracy at 25, 50, and 75 µg mL-1 concentrations, showing satisfactory recovery rate after addition of the standard. The analytical methodology described proved to be simple, fast, safe and was considered valid.
盐酸万古霉素是一种含有氨基酸和糖的三环糖肽。该物质适用于静脉输注治疗革兰氏阳性菌引起的严重感染。本研究的目的是通过评估选择性、线性、工作范围、基质效应、稳健性、精密度和准确性等参数，开发并验证一种通过高效液相色谱紫外检测（HPLC-UV）测定盐酸万古霉素含量的分析方法。所用样品为小瓶中的万古霉素盐酸盐，并在HPLC-UV系统上进行分析，C18反相柱在30°C、pH=4和二极管阵列检测（220nm）下进行。流动相由乙腈和磷酸二氢铵缓冲液（8:92 v/v）组成，流速为1 mL min-1，进样体积为20μL，运行时间为15分钟。该方法已被证明是选择性的，不受流动相干扰，稀释剂等物质对万古霉素盐酸盐的保留时间；该方法在25至175µg mL-1范围内呈线性；基质效应显示出线条之间的平行性，从而表明基质成分在感兴趣化合物的分析中不存在干扰；该方法是稳健的，药物变化与流动相流速和柱温度变化引起的故意变化成比例；该方法在25、50和75µg mL-1浓度下显示出准确度，添加标准品后显示出令人满意的回收率。所描述的分析方法被证明是简单、快速、安全的，并且被认为是有效的。
{"title":"Development and Validation of a High Performance Liquid Chromatography Ultraviolet Detection Method for the Quantitative Determination of Vancomycin Hydrochloride","authors":"P. Onofre, D. Barros, Gabriela Silva, F. Fonseca, P. Rosa, M. Pedreira, M. Peterlini","doi":"10.30744/brjac.2179-3425.tn-80-2022","DOIUrl":"https://doi.org/10.30744/brjac.2179-3425.tn-80-2022","url":null,"abstract":"Vancomycin hydrochloride is a tricyclic glycopeptide that contains amino acids and sugars. This substance is indicated to treat serious infections caused by Gram-positive bacteria by intravenous infusion. The objective of this study was to develop and validate an analytical methodology by high performance liquid chromatography with ultraviolet detection (HPLC-UV) to determine vancomycin hydrochloride content by assessing the parameters of selectivity, linearity, working range, matrix effect, robustness, precision, and accuracy. The sample used was vancomycin hydrochloride in a vial and analyzes were carried out on HPLC-UV system, with C18 reverse-phase column at 30 °C, pH=4 and diode-array detection (220 nm). The mobile phase was composed of acetonitrile and monobasic ammonium phosphate buffer (8:92 v/v), 1 mL min-1 flow, injection volume of 20 μL and 15 minute of run time. The method has been shown to be selective, free from mobile phase interference, diluent and other substances on vancomycin hydrochloride retention time; the method is linear in the range between 25 and 175 µg mL-1; matrix effect showed parallelism between the lines, thus indicating the absence of interference of the matrix constituents in analysis of the compound of interest; the method was robust with drug variations proportional to the deliberate changes caused by the change in the flow rate of the mobile phase and in the column temperature; the method showed accuracy at 25, 50, and 75 µg mL-1 concentrations, showing satisfactory recovery rate after addition of the standard. The analytical methodology described proved to be simple, fast, safe and was considered valid.","PeriodicalId":9115,"journal":{"name":"Brazilian Journal of Analytical Chemistry","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2023-03-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48061708","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 : 2023-03-02DOI: 10.30744/brjac.2179-3425.ar-135-2022
Luana da Costa, M. Arruda
A methodology for simultaneous hydride forming elements was established with accuracy and precision, and alicable to different generations of the soybean seeds. In fact, a unique condition for As, Se, Sb and Te determination by hydride-generation coupled to ICP-MS was established as the optimized concentrations of HCl at 6 mol/L and sodium tetrahydroborate at 0.3% (m v-1), and the analytical curve prepared containing all four elements ranging from 10 to 100 ng L-1. For checking the accuracy, the NIST SRM 1568a (Rice Flour) material was used, and good recoveries ranging from 71.7 to 126% were found for the hydrides forming elements. After optimizing, the method was alied to different generations of soybean seeds, indicating a low content of As (from 17 to 29 ng kg-1) and Se (from 42 to 50 ng kg-1) in some of these generations, and concentrations below the LOQ for Sb and Te. All evaluations were obtained after analyzing, at least, in triplicates. Although found low concentrations for As and Se, these results are, at least, intriguing, because they not follow a tendency along generations, and they are discussed along the text.
{"title":"Simultaneous Hydride Generation Inductively Coupled Plasma Mass Spectrometry for the Evaluation of Different Generations of Soybean Seeds","authors":"Luana da Costa, M. Arruda","doi":"10.30744/brjac.2179-3425.ar-135-2022","DOIUrl":"https://doi.org/10.30744/brjac.2179-3425.ar-135-2022","url":null,"abstract":"A methodology for simultaneous hydride forming elements was established with accuracy and precision, and alicable to different generations of the soybean seeds. In fact, a unique condition for As, Se, Sb and Te determination by hydride-generation coupled to ICP-MS was established as the optimized concentrations of HCl at 6 mol/L and sodium tetrahydroborate at 0.3% (m v-1), and the analytical curve prepared containing all four elements ranging from 10 to 100 ng L-1. For checking the accuracy, the NIST SRM 1568a (Rice Flour) material was used, and good recoveries ranging from 71.7 to 126% were found for the hydrides forming elements. After optimizing, the method was alied to different generations of soybean seeds, indicating a low content of As (from 17 to 29 ng kg-1) and Se (from 42 to 50 ng kg-1) in some of these generations, and concentrations below the LOQ for Sb and Te. All evaluations were obtained after analyzing, at least, in triplicates. Although found low concentrations for As and Se, these results are, at least, intriguing, because they not follow a tendency along generations, and they are discussed along the text.","PeriodicalId":9115,"journal":{"name":"Brazilian Journal of Analytical Chemistry","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2023-03-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48202170","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 : 2023-02-10DOI: 10.30744/brjac.2179-3425.ar-121-2022
M. Mesko, R. Pereira, Natalia Bielemann, F. Rondan, D. Novo
The determination of iodine in iodized mineral dietary supplements is considered a challenge, especially in view of the variety in the sample composition and the analyte concentration. Thus, in this work, microwave-induced combustion (MIC) was combined with ion chromatography (IC) and ion-selective electrode potentiometry (ISE) for iodine determination and dose uniformity assays in mineral dietary supplements. Sample masses up to 800 mg were efficiently digested and only a diluted alkaline solution (200 mmol L-1 NH4OH) was necessary to absorb the analyte for further determination step. The final digest was fully compatible with multi-technique detection usually available in routine analysis laboratories. Recoveries ranging from 94% to 106% was achieved and relative standard deviations for repeatability and intermediate precision were always lower than 8%. Limits of quantification were 4 µg g-1 and 10 µg g-1, respectively, by using IC and ISE. The analytical method was applied for iodine determination in mineral dietary supplements from four brands with different iodine dosages (from 100 to 1250 μg g-1, according to the manufacturers) and for uniformity assay evaluation using individual tablets/capsules of mineral dietary supplements. Non-compliance regarding label information for some samples was reported, drawing the attention of supervisory institutions. The analytical strategies presented in the present study can be successfully used in routine analysis of the quality control of mineral dietary supplements.
{"title":"Multi-Techniques for Iodine Determination and Dose Uniformity Assays in Iodized Mineral Dietary Supplements","authors":"M. Mesko, R. Pereira, Natalia Bielemann, F. Rondan, D. Novo","doi":"10.30744/brjac.2179-3425.ar-121-2022","DOIUrl":"https://doi.org/10.30744/brjac.2179-3425.ar-121-2022","url":null,"abstract":"The determination of iodine in iodized mineral dietary supplements is considered a challenge, especially in view of the variety in the sample composition and the analyte concentration. Thus, in this work, microwave-induced combustion (MIC) was combined with ion chromatography (IC) and ion-selective electrode potentiometry (ISE) for iodine determination and dose uniformity assays in mineral dietary supplements. Sample masses up to 800 mg were efficiently digested and only a diluted alkaline solution (200 mmol L-1 NH4OH) was necessary to absorb the analyte for further determination step. The final digest was fully compatible with multi-technique detection usually available in routine analysis laboratories. Recoveries ranging from 94% to 106% was achieved and relative standard deviations for repeatability and intermediate precision were always lower than 8%. Limits of quantification were 4 µg g-1 and 10 µg g-1, respectively, by using IC and ISE. The analytical method was applied for iodine determination in mineral dietary supplements from four brands with different iodine dosages (from 100 to 1250 μg g-1, according to the manufacturers) and for uniformity assay evaluation using individual tablets/capsules of mineral dietary supplements. Non-compliance regarding label information for some samples was reported, drawing the attention of supervisory institutions. The analytical strategies presented in the present study can be successfully used in routine analysis of the quality control of mineral dietary supplements.","PeriodicalId":9115,"journal":{"name":"Brazilian Journal of Analytical Chemistry","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2023-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47310817","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 : 2023-02-03DOI: 10.30744/brjac.2179-3425.tn-94-2022
Graciela Heidrich, V. Neves, N. Stefanello, V. Miron, T. Lopes, Sindy Krzyzaniak, Paola Mello, M. Schetinger, D. Pozebon, V. Dressler
Adult Wistar rats were exposed to lanthanum oxide nanoparticles (La2O3-NPs). Animals were initially treated with single doses of La2O3-NPs suspensions at 5.0, 50, 300 and 2000 mg kg-1 per body weight (bw), which were orally administered. Behavior changes, symptoms of intoxication and mortality were not observed for individuals treated with the La2O3-NPs. However, the histological analysis of different organs of the treated rats revealed that 300 mg kg-1 and 2000 mg kg-1 bw La2O3-NPs caused hepatic lesions. Subsequently, 40 individuals were divided in four groups with 10 individuals in each group and daily treated with water only (control) and with 1.0, 10 and 100 mg kg-1 bw La2O3-NPs. After 30 days, it was observed that the La2O3-NPs did not affect the body weight and organs weight of the animals. The La2O3-NPs also did not change the levels of creatinine, urea, glutamyl transferase (γ-GT), alanine aminotransferase (ALT), aspartate aminotransferase (AST) and thiobarbituric acid reactive substances (TBARS) in blood serum. Neurotoxicity, evaluated by the acetylcholinesterase (AChE) activity, was not observed as well. An increase of reactive oxygen species (ROS) was found in kidney of rats treated with 100 mg kg-1 bw La2O3-NPs. Conversely, protein oxidation decreased in the liver of those animals. The catalase (CAT) activity was not affected by La2O3-NPs and that of superoxide dismutase (SOD) was in the liver of animals treated with 10 mg kg-1 bw La2O3-NPs. Lanthanum was determined in organs and blood of the treated animals. The element was not detected in the blood but was in the organs, in higher concentration in liver, kidneys, and heart. Lanthanum present in the form of NPs or as free ion could not be detected. As such, it is worth investigating possible transformation of La2O3-NPs in the organism, their elimination routes, and effects of longer exposure times.
{"title":"Lanthanum Oxide Nanoparticles Distribution in Wistar Rats after Oral Exposure and Respective Effects","authors":"Graciela Heidrich, V. Neves, N. Stefanello, V. Miron, T. Lopes, Sindy Krzyzaniak, Paola Mello, M. Schetinger, D. Pozebon, V. Dressler","doi":"10.30744/brjac.2179-3425.tn-94-2022","DOIUrl":"https://doi.org/10.30744/brjac.2179-3425.tn-94-2022","url":null,"abstract":"Adult Wistar rats were exposed to lanthanum oxide nanoparticles (La2O3-NPs). Animals were initially treated with single doses of La2O3-NPs suspensions at 5.0, 50, 300 and 2000 mg kg-1 per body weight (bw), which were orally administered. Behavior changes, symptoms of intoxication and mortality were not observed for individuals treated with the La2O3-NPs. However, the histological analysis of different organs of the treated rats revealed that 300 mg kg-1 and 2000 mg kg-1 bw La2O3-NPs caused hepatic lesions. Subsequently, 40 individuals were divided in four groups with 10 individuals in each group and daily treated with water only (control) and with 1.0, 10 and 100 mg kg-1 bw La2O3-NPs. After 30 days, it was observed that the La2O3-NPs did not affect the body weight and organs weight of the animals. The La2O3-NPs also did not change the levels of creatinine, urea, glutamyl transferase (γ-GT), alanine aminotransferase (ALT), aspartate aminotransferase (AST) and thiobarbituric acid reactive substances (TBARS) in blood serum. Neurotoxicity, evaluated by the acetylcholinesterase (AChE) activity, was not observed as well. An increase of reactive oxygen species (ROS) was found in kidney of rats treated with 100 mg kg-1 bw La2O3-NPs. Conversely, protein oxidation decreased in the liver of those animals. The catalase (CAT) activity was not affected by La2O3-NPs and that of superoxide dismutase (SOD) was in the liver of animals treated with 10 mg kg-1 bw La2O3-NPs. Lanthanum was determined in organs and blood of the treated animals. The element was not detected in the blood but was in the organs, in higher concentration in liver, kidneys, and heart. Lanthanum present in the form of NPs or as free ion could not be detected. As such, it is worth investigating possible transformation of La2O3-NPs in the organism, their elimination routes, and effects of longer exposure times.","PeriodicalId":9115,"journal":{"name":"Brazilian Journal of Analytical Chemistry","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2023-02-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45727229","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 : 2023-01-19DOI: 10.30744/brjac.2179-3425.ar-125-2022
Florencia Tissot, Maite Cuadrado, J. Santander, J. Torres, I. Machado
Moringa stenopetala is a tropical tree from the Moringaceae family, native to north-east Africa, that has widespread to many countries. It is highly valued for the associated nutritional and medicinal properties. The nutritional value of South American Moringa stenopetala was assessed in this work, giving some deeper insight into the expected biological accessibility of the main nutrients present in raw leaves and prepared infusions. Metal ions were determined by FAAS; L-ascorbic acid, leucine, and tryptophan by LC-DAD; rutin, isoquercitrin and neochlorogenic acid by LC-ESI-MS/MS. Metal ions content in analyzed specimens was in the same order of previously reported data, except for lower values for iron, probably associated to the different soil composition. Tested amino acids were also found in the previously reported range, while higher contents of L-ascorbic acid, rutin and neochlorogenic acid were determined. Interestingly, transfer factors to infusions resulted especially low for magnesium, calcium, iron, and L-ascorbic acid, indicating that the way of consumption exerts a strong influence on the nutritional value of the vegetal material. Chemical speciation modeling experiments to predict bioaccessibility showed that sodium, potassium, magnesium, and calcium ions to be predominantly free. On the other hand, the micronutrients are predicted to be partly associated to polyphenolic compounds. Finally, the antioxidant activity was studied both in the vegetal material and the prepared infusions by the ORAC assay, both showing relevant antioxidant activity probably associated to the high rutin content. This biomolecule, together with other polyphenolic compounds present, are expected to partially retain metal ions in solution, also contributing to the antioxidant beneficial properties of Moringa stenopetala.
{"title":"Nutritional and Antioxidant Properties of South American Moringa stenopetala","authors":"Florencia Tissot, Maite Cuadrado, J. Santander, J. Torres, I. Machado","doi":"10.30744/brjac.2179-3425.ar-125-2022","DOIUrl":"https://doi.org/10.30744/brjac.2179-3425.ar-125-2022","url":null,"abstract":"Moringa stenopetala is a tropical tree from the Moringaceae family, native to north-east Africa, that has widespread to many countries. It is highly valued for the associated nutritional and medicinal properties. The nutritional value of South American Moringa stenopetala was assessed in this work, giving some deeper insight into the expected biological accessibility of the main nutrients present in raw leaves and prepared infusions. Metal ions were determined by FAAS; L-ascorbic acid, leucine, and tryptophan by LC-DAD; rutin, isoquercitrin and neochlorogenic acid by LC-ESI-MS/MS. Metal ions content in analyzed specimens was in the same order of previously reported data, except for lower values for iron, probably associated to the different soil composition. Tested amino acids were also found in the previously reported range, while higher contents of L-ascorbic acid, rutin and neochlorogenic acid were determined. Interestingly, transfer factors to infusions resulted especially low for magnesium, calcium, iron, and L-ascorbic acid, indicating that the way of consumption exerts a strong influence on the nutritional value of the vegetal material. Chemical speciation modeling experiments to predict bioaccessibility showed that sodium, potassium, magnesium, and calcium ions to be predominantly free. On the other hand, the micronutrients are predicted to be partly associated to polyphenolic compounds. Finally, the antioxidant activity was studied both in the vegetal material and the prepared infusions by the ORAC assay, both showing relevant antioxidant activity probably associated to the high rutin content. This biomolecule, together with other polyphenolic compounds present, are expected to partially retain metal ions in solution, also contributing to the antioxidant beneficial properties of Moringa stenopetala.","PeriodicalId":9115,"journal":{"name":"Brazilian Journal of Analytical Chemistry","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2023-01-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44385739","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.letter-hudsoncarvalho.n38
H. Carvalho
Elemental chemical images reveal how the elements are distributed in a sample. While it may sound useless for a homogeneous solution, it is crucial for understanding properties of heterogeneous systems, such as a rock1, a cereal grain2, or a painting3. In such cases, revealing the chemical composition of parts of the sample might reveal the distribution of minerals, nutrients, or toxic elements. All strategies for measuring the spatial distribution of elements require a probe, whose size will define the lateral resolution of the image, and a detection system. Some techniques are destructive while others preserve the specimen; this latter feature is of special importance for rare and mass-limited samples or in the case of in vivo analysis. Laser ablation coupled to mass spectrometry or optical emission spectrometry, laser induced break down spectrometry, and microprobe X-ray fluorescence spectrometry are some of the most common laboratory techniques employed in chemical imaging.
{"title":"Past, Present, and Future of X-ray Fluorescence Chemical Imaging","authors":"H. Carvalho","doi":"10.30744/brjac.2179-3425.letter-hudsoncarvalho.n38","DOIUrl":"https://doi.org/10.30744/brjac.2179-3425.letter-hudsoncarvalho.n38","url":null,"abstract":"Elemental chemical images reveal how the elements are distributed in a sample. While it may sound useless for a homogeneous solution, it is crucial for understanding properties of heterogeneous systems, such as a rock1, a cereal grain2, or a painting3. In such cases, revealing the chemical composition of parts of the sample might reveal the distribution of minerals, nutrients, or toxic elements. All strategies for measuring the spatial distribution of elements require a probe, whose size will define the lateral resolution of the image, and a detection system. Some techniques are destructive while others preserve the specimen; this latter feature is of special importance for rare and mass-limited samples or in the case of in vivo analysis. Laser ablation coupled to mass spectrometry or optical emission spectrometry, laser induced break down spectrometry, and microprobe X-ray fluorescence spectrometry are some of the most common laboratory techniques employed in chemical imaging.","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":"46041127","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.dressler
V. Dressler
Valderi Luiz Dressler holds a chemistry degree (1992) and a master’s in chemistry (1994) from the Federal University of Santa Maria (UFSM), RS, Brazil, a PhD in chemistry (1999) from the Federal University of Santa Catarina, SC, Brazil and post-doctorates from Forschungszentrum Julich GmbH, Germany (2007 and 2010). Currently, he is a full professor and coordinator of the industrial chemistry and bachelor's chemistry degree courses at the UFSM. Dr. Dressler’s research activities mainly include trace analysis and environmental chemistry, involving the techniques of atomic absorption spectrometry (AAS), inductively coupled plasma optical emission spectrometry (ICP-OES), inductively coupled plasma mass spectrometry (ICP-MS), flow injection analysis (FIA), electrothermal vaporization (ETV) and laser ablation (LA). Furthermore, he performs chemical speciation analysis studies involving hyphenated techniques such as liquid and gas chromatography coupled to ICP-MS and also FIA systems coupled to AAS.
{"title":"Professor Valderi Dressler, a great admirer of young Brazilian scientists, kindly granted BrJAC an interview","authors":"V. Dressler","doi":"10.30744/brjac.2179-3425.interview.dressler","DOIUrl":"https://doi.org/10.30744/brjac.2179-3425.interview.dressler","url":null,"abstract":"Valderi Luiz Dressler holds a chemistry degree (1992) and a master’s in chemistry (1994) from the Federal University of Santa Maria (UFSM), RS, Brazil, a PhD in chemistry (1999) from the Federal University of Santa Catarina, SC, Brazil and post-doctorates from Forschungszentrum Julich GmbH, Germany (2007 and 2010). Currently, he is a full professor and coordinator of the industrial chemistry and bachelor's chemistry degree courses at the UFSM. Dr. Dressler’s research activities mainly include trace analysis and environmental chemistry, involving the techniques of atomic absorption spectrometry (AAS), inductively coupled plasma optical emission spectrometry (ICP-OES), inductively coupled plasma mass spectrometry (ICP-MS), flow injection analysis (FIA), electrothermal vaporization (ETV) and laser ablation (LA). Furthermore, he performs chemical speciation analysis studies involving hyphenated techniques such as liquid and gas chromatography coupled to ICP-MS and also FIA systems coupled to AAS.","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":"49669658","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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