Pub Date : 2023-10-06DOI: 10.30744/brjac.2179-3425.editorial.imachado.n41
Ignacio Machado
One of the simplest definitions for analytical chemistry is “the branch of chemistry concerned with analysis.”1 But what does "analysis" really mean? In the past it was synonymous for decomposition. However, with the rise of new technologies, it is no longer necessary to destroy samples to know their composition. Therefore, the current meaning of analysis refers to the identification and quantification of different analytes without the need for decomposition. However, analytical chemists do not merely provide results; they also develop strategies to measure different chemical properties. Furthermore, they spend an enormous amount of time interpreting the obtained data. Thus, considering the vast variety of works involving analytical chemistry, a more comprehensive definition of the discipline is required. Analytical chemistry was defined in the second half of the 20th century as “the chemical discipline that gains information on the chemical composition and structure of substances, particularly on the type of species, their amount, possible temporal and spatial changes, and structural relationships between the constituents.”2 In 1993, the Working Party on Analytical Chemistry (WPAC) of the Federation of European Chemical Societies (FECS) defined analytical chemistry as “a scientific discipline that develops and applies methods, instruments, and strategies to obtain information on the composition and nature of matter in space and time,” indicating that the development of methods and instruments is a central part of this science.3 However, some analytical chemists consider that this sort of definition does not entirely reflect the identity and wide scope of analytical chemistry. In the year 2000, Professor Miguel Valcárcel proposed a more comprehensive definition for analytical chemistry as “a metrological science that develops, optimizes and applies material, methodological and strategic tools of widely variable nature which materialize in measurement processes intended to derive quality (bio)chemical information of both partial [presence or concentration of bio(chemical) analyte species] and global nature on materials or systems of widely variable nature (chemical, biochemical and biological) in space and time in order to solve scientific, technical and social problems.”4 This constitutes a very encompassing definition because it includes more complete information that contributes to a deeper characterization and understanding of the discipline, while highlighting the different capabilities and approaches as well as some of the challenges. So, many definitions can be found in the literature. The truth is that while some definitions express essential aspects of (bio)analytical chemistry and the analytical work, others characterize it in a very concise way. Furthermore, while some authors consider it to be a branch of chemistry independent of other chemical disciplines, others classify it as an autonomous science called analytical sciences.4 The im
{"title":"What is the Best Definition for (Bio)Analytical Chemistry?","authors":"Ignacio Machado","doi":"10.30744/brjac.2179-3425.editorial.imachado.n41","DOIUrl":"https://doi.org/10.30744/brjac.2179-3425.editorial.imachado.n41","url":null,"abstract":"One of the simplest definitions for analytical chemistry is “the branch of chemistry concerned with analysis.”1 But what does \"analysis\" really mean? In the past it was synonymous for decomposition. However, with the rise of new technologies, it is no longer necessary to destroy samples to know their composition. Therefore, the current meaning of analysis refers to the identification and quantification of different analytes without the need for decomposition. However, analytical chemists do not merely provide results; they also develop strategies to measure different chemical properties. Furthermore, they spend an enormous amount of time interpreting the obtained data. Thus, considering the vast variety of works involving analytical chemistry, a more comprehensive definition of the discipline is required. Analytical chemistry was defined in the second half of the 20th century as “the chemical discipline that gains information on the chemical composition and structure of substances, particularly on the type of species, their amount, possible temporal and spatial changes, and structural relationships between the constituents.”2 In 1993, the Working Party on Analytical Chemistry (WPAC) of the Federation of European Chemical Societies (FECS) defined analytical chemistry as “a scientific discipline that develops and applies methods, instruments, and strategies to obtain information on the composition and nature of matter in space and time,” indicating that the development of methods and instruments is a central part of this science.3 However, some analytical chemists consider that this sort of definition does not entirely reflect the identity and wide scope of analytical chemistry. In the year 2000, Professor Miguel Valcárcel proposed a more comprehensive definition for analytical chemistry as “a metrological science that develops, optimizes and applies material, methodological and strategic tools of widely variable nature which materialize in measurement processes intended to derive quality (bio)chemical information of both partial [presence or concentration of bio(chemical) analyte species] and global nature on materials or systems of widely variable nature (chemical, biochemical and biological) in space and time in order to solve scientific, technical and social problems.”4 This constitutes a very encompassing definition because it includes more complete information that contributes to a deeper characterization and understanding of the discipline, while highlighting the different capabilities and approaches as well as some of the challenges. So, many definitions can be found in the literature. The truth is that while some definitions express essential aspects of (bio)analytical chemistry and the analytical work, others characterize it in a very concise way. Furthermore, while some authors consider it to be a branch of chemistry independent of other chemical disciplines, others classify it as an autonomous science called analytical sciences.4 The im","PeriodicalId":9115,"journal":{"name":"Brazilian Journal of Analytical Chemistry","volume":"102 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134944708","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 : 2023-09-19DOI: 10.30744/brjac.2179-3425.ar-46-2023
Eliezer de Oliveira, Bianca da Silva, Carla Bottoli
Abamectin has been used by seed treatment to control plant-parasitic nematodes in Brazil. In this work, foliar spray was performed as an alternative application method and a LC-MS/MS method employing QuEChERS for sample preparation was developed for the analysis of abamectin in soybean roots. For this, abamectin was applied on the leaves and the translocation of this pesticide from leaves to roots was evaluated. The method was validated and presented adequate selectivity. Matrix-matched was used as an approach to calibration. Good linearity of the analytical curve was obtained over the studied range of concentrations from 0.10 to 1.0 mg kg-1, with a determination coefficient of 0.995. The limit of detection was 0.05 mg kg-1, and the limit of quantification was 0.10 mg kg-1. Recoveries were in the range of 99 to 106% and RSD < 20%. Finally, root samples after foliar spray were analyzed, and abamectin was not detected.
{"title":"Determination of Abamectin in Soybean Roots by Liquid Chromatography Coupled to Tandem Mass Spectrometry","authors":"Eliezer de Oliveira, Bianca da Silva, Carla Bottoli","doi":"10.30744/brjac.2179-3425.ar-46-2023","DOIUrl":"https://doi.org/10.30744/brjac.2179-3425.ar-46-2023","url":null,"abstract":"Abamectin has been used by seed treatment to control plant-parasitic nematodes in Brazil. In this work, foliar spray was performed as an alternative application method and a LC-MS/MS method employing QuEChERS for sample preparation was developed for the analysis of abamectin in soybean roots. For this, abamectin was applied on the leaves and the translocation of this pesticide from leaves to roots was evaluated. The method was validated and presented adequate selectivity. Matrix-matched was used as an approach to calibration. Good linearity of the analytical curve was obtained over the studied range of concentrations from 0.10 to 1.0 mg kg-1, with a determination coefficient of 0.995. The limit of detection was 0.05 mg kg-1, and the limit of quantification was 0.10 mg kg-1. Recoveries were in the range of 99 to 106% and RSD < 20%. Finally, root samples after foliar spray were analyzed, and abamectin was not detected.","PeriodicalId":9115,"journal":{"name":"Brazilian Journal of Analytical Chemistry","volume":"28 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135107106","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 : 2023-09-18DOI: 10.30744/brjac.2179-3425.ar-47-2023
Gabrielle Iop, Alice Holkem, Andres de Souza, Edson Muller, Juliano Barin, Paola Mello
A miniaturized method using a portable device with digital image acquisition and PhotoMetrix PRO app data treatment was developed for the determination of basic nitrogen content in diesel oil. The method was based on the colorimetric titration described in the UOP 269-10 standard protocol. A homemade 3D-printed chamber with controlled light intensity equipped with an USB camera was used for image acquisition after an acid-base titration reaction, carried out in a miniaturized device. After mixing reagents and diesel oil, the images were obtained and converted into RGB (red, green, and blue) histograms, and a partial least squares (PLS) multivariate calibration model was constructed. Parameters of the regression model were evaluated, by the coefficient of determination (R2), the root mean squared error of calibration (RMSEC), the root mean squared error of cross-validation (RMSECV), and the root mean squared error of prediction (RMSEP). Some conditions for the acid-base titration were optimized, such as the concentration of the indicator (68.0 to 272 µmol L-1) and the titrating (HClO4, 0.179 to 1.79 mmol L-1), as well as the volume of diesel oil. With 60 µL of 2.54 mmol L-1 indicator solution, 20 µL of 20 mmol L-1 HClO4 as titrating and using 50 to 1000 µL of diesel oil, optimal conditions were obtained for calibration (RMSEP of 0.377 mg kg-1, RMSECV of 0.307 mg kg-1 with 4 factors). It is important to mention that no differences were observed (p < 0.05) when comparing reference values with the results by the proposed protocol. This proved to be advantageous in relation to the methods described in the UOP 269-10 standard since it was possible to reduce the consumption of reagents and waste generation, in agreement with green analytical chemistry. In addition, this alternative protocol combines simplicity and speed to obtain results with good accuracy, precision and suitable limit of quantification (1 mg kg-1) using a miniaturized system.
{"title":"Determination of basic nitrogen content in diesel oil: A miniaturized method by digital image-based colorimetry in a portable device","authors":"Gabrielle Iop, Alice Holkem, Andres de Souza, Edson Muller, Juliano Barin, Paola Mello","doi":"10.30744/brjac.2179-3425.ar-47-2023","DOIUrl":"https://doi.org/10.30744/brjac.2179-3425.ar-47-2023","url":null,"abstract":"A miniaturized method using a portable device with digital image acquisition and PhotoMetrix PRO app data treatment was developed for the determination of basic nitrogen content in diesel oil. The method was based on the colorimetric titration described in the UOP 269-10 standard protocol. A homemade 3D-printed chamber with controlled light intensity equipped with an USB camera was used for image acquisition after an acid-base titration reaction, carried out in a miniaturized device. After mixing reagents and diesel oil, the images were obtained and converted into RGB (red, green, and blue) histograms, and a partial least squares (PLS) multivariate calibration model was constructed. Parameters of the regression model were evaluated, by the coefficient of determination (R2), the root mean squared error of calibration (RMSEC), the root mean squared error of cross-validation (RMSECV), and the root mean squared error of prediction (RMSEP). Some conditions for the acid-base titration were optimized, such as the concentration of the indicator (68.0 to 272 µmol L-1) and the titrating (HClO4, 0.179 to 1.79 mmol L-1), as well as the volume of diesel oil. With 60 µL of 2.54 mmol L-1 indicator solution, 20 µL of 20 mmol L-1 HClO4 as titrating and using 50 to 1000 µL of diesel oil, optimal conditions were obtained for calibration (RMSEP of 0.377 mg kg-1, RMSECV of 0.307 mg kg-1 with 4 factors). It is important to mention that no differences were observed (p < 0.05) when comparing reference values with the results by the proposed protocol. This proved to be advantageous in relation to the methods described in the UOP 269-10 standard since it was possible to reduce the consumption of reagents and waste generation, in agreement with green analytical chemistry. In addition, this alternative protocol combines simplicity and speed to obtain results with good accuracy, precision and suitable limit of quantification (1 mg kg-1) using a miniaturized system.","PeriodicalId":9115,"journal":{"name":"Brazilian Journal of Analytical Chemistry","volume":"28 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135202704","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 : 2023-09-11DOI: 10.30744/brjac.2179-3425.ar-51-2023
Karen Giacobe, Débora de Almeida, Samuel Waechter, Fabio Duarte, Cezar Bizzi
In this work, a sample preparation method based on ultrasound-assisted extraction (UAE) for the determination of Al, Ba, Ca, Fe, K, Mg, Mn, Na, P, Sr, and Zn in lignocellulosic biomasses (sugarcane bagasse, eucalyptus wood residues, and pine wood residues) was evaluated. Reference values were achieved following the EN ISO 16967, which was based on a microwave-assisted wet digestion sample preparation method for further element determination by inductively coupled plasma optical emission spectrometry (ICP OES). The optimizations for the proposed UAE method were performed using 250 mg of sugarcane bagasse sample, where the ultrasonic bath frequency (25, 35, 37, 45, 80, and 130 kHz), and acoustic amplitude (50, 70 and 100%) were evaluated. After selecting the most efficient extractant solvent (20 mL of 1 mol L-1 of H2O2, HNO3, H2SO4, H2O, or CH2O2), the extraction temperature (20, 50, or 70 ºC) and time (15, 30, or 40 min) were evaluated. The most efficient extraction condition using the UAE method employed 45 kHz (70% amplitude), 20 mL of 1 mol L-1 of H2SO4, and 50 °C for 30 min. The optimized UAE was used for extraction and subsequent element determination in residues of pine wood and eucalyptus wood. Although poor recoveries were observed for Al, Ba, and Fe (lower than 75%), the results for Ca, K, Mg, Mn, Na, P, Sr, and Zn were in agreement (Student t-test, 95% confidence level) with those obtained by EN ISO 16967. Therefore, the proposed UAE method proved to be efficient for the determination of most of the evaluated elements in lignocellulosic biomasses with different matrix complexity, employing milder extraction conditions and diluted reagents.
本文研究了一种基于超声辅助提取(UAE)的样品制备方法，用于测定木质纤维素生物质(甘蔗甘蔗渣、桉树木渣和松木渣)中Al、Ba、Ca、Fe、K、Mg、Mn、Na、P、Sr和Zn的含量。参照EN ISO 16967标准，采用微波辅助湿消解样品制备方法，通过电感耦合等离子体光学发射光谱法(ICP OES)进一步测定元素。采用250 mg甘蔗渣样品，对超声浴频率(25、35、37、45、80和130 kHz)和声波振幅(50、70和100%)进行了优化。选择最有效的萃取溶剂(1 mol L-1的H2O2、HNO3、H2SO4、H2O或CH2O2各20 mL)后，评估萃取温度(20、50或70℃)和时间(15、30或40 min)。最有效的提取条件为45 kHz(70%振幅)、20 mL (1 mol L-1) H2SO4、50°C、30 min。优化后的UAE用于松木和桉木残留物的提取和随后的元素测定。虽然观察到Al, Ba和Fe的回收率较低(低于75%)，但Ca, K, Mg, Mn, Na, P, Sr和Zn的结果与EN ISO 16967获得的结果一致(学生t检验，95%置信水平)。因此，采用较温和的提取条件和稀释的试剂，所提出的UAE方法可以有效地测定不同基质复杂性的木质纤维素生物质中大多数被评价的元素。
{"title":"Ultrasound-assisted Extraction Method for Element Determination in Lignocellulosic Biomass","authors":"Karen Giacobe, Débora de Almeida, Samuel Waechter, Fabio Duarte, Cezar Bizzi","doi":"10.30744/brjac.2179-3425.ar-51-2023","DOIUrl":"https://doi.org/10.30744/brjac.2179-3425.ar-51-2023","url":null,"abstract":"In this work, a sample preparation method based on ultrasound-assisted extraction (UAE) for the determination of Al, Ba, Ca, Fe, K, Mg, Mn, Na, P, Sr, and Zn in lignocellulosic biomasses (sugarcane bagasse, eucalyptus wood residues, and pine wood residues) was evaluated. Reference values were achieved following the EN ISO 16967, which was based on a microwave-assisted wet digestion sample preparation method for further element determination by inductively coupled plasma optical emission spectrometry (ICP OES). The optimizations for the proposed UAE method were performed using 250 mg of sugarcane bagasse sample, where the ultrasonic bath frequency (25, 35, 37, 45, 80, and 130 kHz), and acoustic amplitude (50, 70 and 100%) were evaluated. After selecting the most efficient extractant solvent (20 mL of 1 mol L-1 of H2O2, HNO3, H2SO4, H2O, or CH2O2), the extraction temperature (20, 50, or 70 ºC) and time (15, 30, or 40 min) were evaluated. The most efficient extraction condition using the UAE method employed 45 kHz (70% amplitude), 20 mL of 1 mol L-1 of H2SO4, and 50 °C for 30 min. The optimized UAE was used for extraction and subsequent element determination in residues of pine wood and eucalyptus wood. Although poor recoveries were observed for Al, Ba, and Fe (lower than 75%), the results for Ca, K, Mg, Mn, Na, P, Sr, and Zn were in agreement (Student t-test, 95% confidence level) with those obtained by EN ISO 16967. Therefore, the proposed UAE method proved to be efficient for the determination of most of the evaluated elements in lignocellulosic biomasses with different matrix complexity, employing milder extraction conditions and diluted reagents.","PeriodicalId":9115,"journal":{"name":"Brazilian Journal of Analytical Chemistry","volume":"92 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136023264","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}
A facial freshener, also known as toner, is a cosmetic product that is commonly used to invigorate the face after a busy day. Ethanol serves as a key component in toner, serving multiple purposes such as being a solvent, preservative, and antimicrobial agent. However, it's important to note that toner formulated for normal skin types typically contain ethanol in small concentrations, adhering to a limit of not more than 10%. Therefore, this study aims to determine ethanol levels in toner using the NIR spectroscopy and chemometric techniques. The NIR spectra of the simulated samples were correlated with ethanol concentration using chemometric calibration model. The calibration models used were partial least square (PLS), principal component regression (PCR), and support vector regression (SVR). The calibration model was validated by leave one out cross validation (LOOCV) as well as the external validation, and the precision and accuracy of the method was evaluated. Among the calibration models, the PLS model exhibited the best performance, yielding an impressive R2 0.9976; with an RMSEC value of 0.4364 and RMSECV value of 0.4704. The internal validation yield R2 value more than 0.99 and RMSE of less than 0,4198. Furthermore, external validation showed the R2 and RMSEP value of 0.989 and 0.920 respectively. The %recovery and RSD value were 101.2% and 0.129%. Comparing ethanol measurements obtained through the NIR chemometric method with those obtained using gas chromatography as the reference method, no significant difference was observed at a 95% confidence levels, as indicated by a significance value of 0.231.
{"title":"The Determination of Ethanol Levels in Facial Freshener Using the NIR Spectroscopy and Chemometric Method","authors":"Wahyu Febriyanti, Nia Kristiningrum, Lestyo Wulandari","doi":"10.30744/brjac.2179-3425.ar-96-2022","DOIUrl":"https://doi.org/10.30744/brjac.2179-3425.ar-96-2022","url":null,"abstract":"A facial freshener, also known as toner, is a cosmetic product that is commonly used to invigorate the face after a busy day. Ethanol serves as a key component in toner, serving multiple purposes such as being a solvent, preservative, and antimicrobial agent. However, it's important to note that toner formulated for normal skin types typically contain ethanol in small concentrations, adhering to a limit of not more than 10%. Therefore, this study aims to determine ethanol levels in toner using the NIR spectroscopy and chemometric techniques. The NIR spectra of the simulated samples were correlated with ethanol concentration using chemometric calibration model. The calibration models used were partial least square (PLS), principal component regression (PCR), and support vector regression (SVR). The calibration model was validated by leave one out cross validation (LOOCV) as well as the external validation, and the precision and accuracy of the method was evaluated. Among the calibration models, the PLS model exhibited the best performance, yielding an impressive R2 0.9976; with an RMSEC value of 0.4364 and RMSECV value of 0.4704. The internal validation yield R2 value more than 0.99 and RMSE of less than 0,4198. Furthermore, external validation showed the R2 and RMSEP value of 0.989 and 0.920 respectively. The %recovery and RSD value were 101.2% and 0.129%. Comparing ethanol measurements obtained through the NIR chemometric method with those obtained using gas chromatography as the reference method, no significant difference was observed at a 95% confidence levels, as indicated by a significance value of 0.231.","PeriodicalId":9115,"journal":{"name":"Brazilian Journal of Analytical Chemistry","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136023265","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 : 2023-08-29DOI: 10.30744/brjac.2179-3425.ar-32-2023
Jean Paulo Coll, Michele da Cunha, Maria Alice Amaral, Maurício Padilha, G. da Silva, Daniel Arsand, P. S. Sanches Filho
The objective of this work was to optimize a chromatographic method, combining derivatization (silylation) with MSTFA (N-methyl-N-(trimethylsilyl)trifluoracetamide) and analysis by gas chromatography coupled to mass spectrometry (GC-MS), for the determination of hormones and UV filters selectively, evaluating the effect of derivatization on the chromatographic response. The method developed for the qualitative analysis (SCAN mode) allowed the identification of the analytes more accurately, with similarities of the spectra superior to 80%. The limits of detection and quantification ranged from 0.1 to 1.3 µg L-1 and 0.3 to 4.2 µg L-1 respectively. The quantitative method, combined silylation with chromatographic determination in SIM mode, proved to be precise (Relative standard deviation <7.2%) and exact (relative error <2.0%), with models without lack of fit, and with correlation coefficients linear values greater than 0.9, in accordance with the requirements and standards of the regulatory bodies.
{"title":"Evaluation of the Effect of Silylation in the Development of an Analytical Method for the Determination of UV Filters and Hormones by GC-MS","authors":"Jean Paulo Coll, Michele da Cunha, Maria Alice Amaral, Maurício Padilha, G. da Silva, Daniel Arsand, P. S. Sanches Filho","doi":"10.30744/brjac.2179-3425.ar-32-2023","DOIUrl":"https://doi.org/10.30744/brjac.2179-3425.ar-32-2023","url":null,"abstract":"The objective of this work was to optimize a chromatographic method, combining derivatization (silylation) with MSTFA (N-methyl-N-(trimethylsilyl)trifluoracetamide) and analysis by gas chromatography coupled to mass spectrometry (GC-MS), for the determination of hormones and UV filters selectively, evaluating the effect of derivatization on the chromatographic response. The method developed for the qualitative analysis (SCAN mode) allowed the identification of the analytes more accurately, with similarities of the spectra superior to 80%. The limits of detection and quantification ranged from 0.1 to 1.3 µg L-1 and 0.3 to 4.2 µg L-1 respectively. The quantitative method, combined silylation with chromatographic determination in SIM mode, proved to be precise (Relative standard deviation <7.2%) and exact (relative error <2.0%), with models without lack of fit, and with correlation coefficients linear values greater than 0.9, in accordance with the requirements and standards of the regulatory bodies.","PeriodicalId":9115,"journal":{"name":"Brazilian Journal of Analytical Chemistry","volume":" ","pages":""},"PeriodicalIF":0.7,"publicationDate":"2023-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42425652","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 : 2023-08-25DOI: 10.30744/brjac.2179-3425.ar-44-2023
B. Freire, Michael Monteiro, Jonatas de Oliveira S. Silva, José Fernando de Macedo, E. Sussuchi
This work aims to develop a modified electrode with N-doped carbon dots (CPE/N-CD) for the voltammetric detection of 17α-ethinylestradiol (EE2) in solution. N-doped carbon dot nanoparticles (N-CD) were synthesized using citric acid and urea as the nitrogen source. The N-doped carbon dots were characterized by absorption and emission spectroscopy in the ultraviolet and visible regions, electronic absorption spectroscopy in the infrared region, and Raman Spectroscopy, which showed evidence of the formation of the material. Electrochemical analyses were conducted utilizing Differential Pulse Voltammetry (DPV). After optimization of electrochemical parameters, a calibration plot was produced for the sensor, demonstrating a linear range of 0.01 to 0.80 μmol L-1 (R2 = 0.9969). Additionally, the sensor exhibited a detection limit (LOD) of 0.59 nmol L-1 and a quantification limit (LOQ) of 2.00 nmol L-1. The studies on reproducibility and repeatability revealed RSDs of 1.63% and 3.61% respectively. The results obtained using CPE/N-CD indicate that the developed electrode exhibits excellent analytical performance, making it suitable for identifying and quantifying EE2 in solution.
{"title":"Development of a Modified Electrode with N-doped Carbon Dots for Electrochemical Determination of 17α-ethinylestradiol","authors":"B. Freire, Michael Monteiro, Jonatas de Oliveira S. Silva, José Fernando de Macedo, E. Sussuchi","doi":"10.30744/brjac.2179-3425.ar-44-2023","DOIUrl":"https://doi.org/10.30744/brjac.2179-3425.ar-44-2023","url":null,"abstract":"This work aims to develop a modified electrode with N-doped carbon dots (CPE/N-CD) for the voltammetric detection of 17α-ethinylestradiol (EE2) in solution. N-doped carbon dot nanoparticles (N-CD) were synthesized using citric acid and urea as the nitrogen source. The N-doped carbon dots were characterized by absorption and emission spectroscopy in the ultraviolet and visible regions, electronic absorption spectroscopy in the infrared region, and Raman Spectroscopy, which showed evidence of the formation of the material. Electrochemical analyses were conducted utilizing Differential Pulse Voltammetry (DPV). After optimization of electrochemical parameters, a calibration plot was produced for the sensor, demonstrating a linear range of 0.01 to 0.80 μmol L-1 (R2 = 0.9969). Additionally, the sensor exhibited a detection limit (LOD) of 0.59 nmol L-1 and a quantification limit (LOQ) of 2.00 nmol L-1. The studies on reproducibility and repeatability revealed RSDs of 1.63% and 3.61% respectively. The results obtained using CPE/N-CD indicate that the developed electrode exhibits excellent analytical performance, making it suitable for identifying and quantifying EE2 in solution.","PeriodicalId":9115,"journal":{"name":"Brazilian Journal of Analytical Chemistry","volume":" ","pages":""},"PeriodicalIF":0.7,"publicationDate":"2023-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49318629","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 : 2023-08-21DOI: 10.30744/brjac.2179-3425.ar-34-2023
Wilber Vilcapoma, Julio Pérez
Conventional methods used to quantify vitamin C require expensive equipment; however, the image analysis method has proven to be effective in quantifying various bioactive compounds and could be useful for small industries due to its low cost. In this sense, the objective was to evaluate the use of a Smartphone and image analysis in the quantification of vitamin C in golden berries juice. Calibration curves were elaborated with ascorbic acid standards (2.5-20 mg L-1) and the Folin-Ciocalteu chromophore reagent (10%). Fifteen color parameters (analytical responses) were obtained from images obtained with a Smartphone and the ImageJ program of the colored samples using four backlight colors, to which a principal component analysis was applied using the integrated development environment for R, RStudio. Subsequently, one-way ANOVA and mean comparisons by Tukey's method (α = 0.05) were applied to the best-scoring analytical response's. Ultimately, the quantification of vitamin C in golden berry juice was performed using the image analysis method, which exhibited superior linearity and sensitivity (R2 = 0.9941 and m = 4.91). A comparative assessment was conducted against a spectrophotometric method utilizing the t-Student test for independent samples (α = 0.05), demonstrating no statistically significant difference between the two methods (p > 0.05).
{"title":"Use of Smartphone and Image Analysis in the Quantification of Vitamin C in Golden Berry (Physalis peruviana L.) Juice","authors":"Wilber Vilcapoma, Julio Pérez","doi":"10.30744/brjac.2179-3425.ar-34-2023","DOIUrl":"https://doi.org/10.30744/brjac.2179-3425.ar-34-2023","url":null,"abstract":"Conventional methods used to quantify vitamin C require expensive equipment; however, the image analysis method has proven to be effective in quantifying various bioactive compounds and could be useful for small industries due to its low cost. In this sense, the objective was to evaluate the use of a Smartphone and image analysis in the quantification of vitamin C in golden berries juice. Calibration curves were elaborated with ascorbic acid standards (2.5-20 mg L-1) and the Folin-Ciocalteu chromophore reagent (10%). Fifteen color parameters (analytical responses) were obtained from images obtained with a Smartphone and the ImageJ program of the colored samples using four backlight colors, to which a principal component analysis was applied using the integrated development environment for R, RStudio. Subsequently, one-way ANOVA and mean comparisons by Tukey's method (α = 0.05) were applied to the best-scoring analytical response's. Ultimately, the quantification of vitamin C in golden berry juice was performed using the image analysis method, which exhibited superior linearity and sensitivity (R2 = 0.9941 and m = 4.91). A comparative assessment was conducted against a spectrophotometric method utilizing the t-Student test for independent samples (α = 0.05), demonstrating no statistically significant difference between the two methods (p > 0.05).","PeriodicalId":9115,"journal":{"name":"Brazilian Journal of Analytical Chemistry","volume":" ","pages":""},"PeriodicalIF":0.7,"publicationDate":"2023-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48842730","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}
Due to its better sensitivity and selectivity, liquid chromatography with tandem mass spectrometry is the preferred choice for the quantification and identification of biomarkers, parent molecules/ metabolites in human saliva, plasma and urine etc. All such quantification methods for melatonin in biological matrices have been summarized. Melatonin is considered as a potential biomarker for circadian rhythm disturbance related disorders such as cancer, depression, Insomnia, etc. Accurate quantification of melatonin is very challenging and critically depends upon the reproducibility and ruggedness of the analytical method. LC-MS/MS technique is considered as the preferred method of analysis for melatonin as compared to immunoassays. Most of bioanalytical melatonin quantification methods consist of, extraction from the biological matrix analyzing by LC-MS/MS. Our review shows that LC-MS/MS is a rugged and dependable instrument for the robust and precise quantitation of Melatonin. This review compiles key elements like extraction procedure, linearity range, and chromatographic conditions.
{"title":"A Brief Assessment of the Bioanalytical Methods by using LC-MS/MS for the Quantitation of Melatonin: A Potential Biomarker for Sleep-Related Disorders","authors":"Gorav Monga, Sravani Yerram, Shailaja Koppula, Rakesh Kumar, Sandeep Kumar","doi":"10.30744/brjac.2179-3425.rv-143-2022","DOIUrl":"https://doi.org/10.30744/brjac.2179-3425.rv-143-2022","url":null,"abstract":"Due to its better sensitivity and selectivity, liquid chromatography with tandem mass spectrometry is the preferred choice for the quantification and identification of biomarkers, parent molecules/ metabolites in human saliva, plasma and urine etc. All such quantification methods for melatonin in biological matrices have been summarized. Melatonin is considered as a potential biomarker for circadian rhythm disturbance related disorders such as cancer, depression, Insomnia, etc. Accurate quantification of melatonin is very challenging and critically depends upon the reproducibility and ruggedness of the analytical method. LC-MS/MS technique is considered as the preferred method of analysis for melatonin as compared to immunoassays. Most of bioanalytical melatonin quantification methods consist of, extraction from the biological matrix analyzing by LC-MS/MS. Our review shows that LC-MS/MS is a rugged and dependable instrument for the robust and precise quantitation of Melatonin. This review compiles key elements like extraction procedure, linearity range, and chromatographic conditions.","PeriodicalId":9115,"journal":{"name":"Brazilian Journal of Analytical Chemistry","volume":" ","pages":""},"PeriodicalIF":0.7,"publicationDate":"2023-08-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44470906","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 : 2023-07-28DOI: 10.30744/brjac.2179-3425.tn-22-2023
Flávio Bezerra, Y. Sade, Jailton Damasceno, Renata Silva
Warfarin (WAR), brodifacoum (BDF) and bromadiolone (BDL) are compounds present in rodenticides, highly toxic to rats, humans and other animals. These compounds can be detected in complex matrices, such as stomach contents, by liquid chromatography techniques (HPLC) with mass spectrometry (MS) or fluorescence detection (FLD). However, no validated method showed determination of uncertainty in the quantification of these compounds. In this study, we compare the validation parameters of two analytical methods, HPLC FLD and ultra high performance liquid chromatography (UHPLC – MS), with uncertainty estimation for the three cited compounds. The results showed that UHPLC-MS outperformed HPLC FLD, however both methods were considered adequate for detection of WAR, BDF or BDL in samples of simulated human stomach contents, especially in cases of suspected contamination.
{"title":"Validation and Uncertainty Calculation of Rodenticide Analysis Methods in a Simulated Gastric Content Matrix – Uncertainty of Rodenticide Analysis Methods","authors":"Flávio Bezerra, Y. Sade, Jailton Damasceno, Renata Silva","doi":"10.30744/brjac.2179-3425.tn-22-2023","DOIUrl":"https://doi.org/10.30744/brjac.2179-3425.tn-22-2023","url":null,"abstract":"Warfarin (WAR), brodifacoum (BDF) and bromadiolone (BDL) are compounds present in rodenticides, highly toxic to rats, humans and other animals. These compounds can be detected in complex matrices, such as stomach contents, by liquid chromatography techniques (HPLC) with mass spectrometry (MS) or fluorescence detection (FLD). However, no validated method showed determination of uncertainty in the quantification of these compounds. In this study, we compare the validation parameters of two analytical methods, HPLC FLD and ultra high performance liquid chromatography (UHPLC – MS), with uncertainty estimation for the three cited compounds. The results showed that UHPLC-MS outperformed HPLC FLD, however both methods were considered adequate for detection of WAR, BDF or BDL in samples of simulated human stomach contents, especially in cases of suspected contamination.","PeriodicalId":9115,"journal":{"name":"Brazilian Journal of Analytical Chemistry","volume":"1 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2023-07-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41473869","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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