Pub Date : 2023-06-08DOI: 10.3390/analytica4020019
Chirapha Prakobdi, P. Saetear
This work presents the first development of an analytical turbidimetric method for the determination of legal alcohols in alcohol-based hand sanitizer products. A typical iodoform reaction is exploited to form a yellow product in the form of precipitates. An iodoform test shows a positive result as yellow precipitates in the presence of ethanol and isopropanol; therefore, the test can only be used to distinguish between methanol and those legal alcohols. In the presence of molecular iodine (I2) and a strong alkaline solution, the legal alcohol is converted to the corresponding carbonyl compound (i.e., ethanol to acetaldehyde, isopropanol to acetone). The susceptibility of this intermediate towards the reaction with hydroxide ions (strong alkaline condition) results in formations of yellow precipitation of iodoform (CHI3) and a water-soluble carboxylate salt in the solution. Therefore, this change allows for the detection of legal alcohols through either naked-eye observation (as semi-quantitative analysis) or a common benchtop/portable photometer/spectrophotometer (as quantitative analysis) by means of turbidimetric analysis. In this work, turbidimetry is employed, which is a useful alternative detection method in analytical practice, especially with colored samples in hand sanitizing products. This is because they can employ wavelengths at which the colored solution does not absorb light. As a result of our developed method, the calibration plots are in the range of 30 to 100% (v/v) for both ethanol and isopropanol. The limit of detection (LOD) (3SD of y-intercept/slope) was found to be 7.4% (v/v) ethanol and 6.5% (v/v) isopropanol. Direct analysis of the non-pretreatment of the sample is achieved. The results indicate that our new proposed analytical method is fit for purpose and valid to detect the legal alcohols in alcohol-based hand sanitizing products for both international and Thai regulations (at least 70% (v/v)). Our quantitative results were also comparable to a standard analytical method, such as the use of a gas chromatography-flame ionization detector (GC-FID). Our developed method and analytical operation could potentially be developed into a practically portable analysis.
{"title":"Iodoform Reaction-Based Turbidimetry for Analysis of Alcohols in Hand Sanitizers","authors":"Chirapha Prakobdi, P. Saetear","doi":"10.3390/analytica4020019","DOIUrl":"https://doi.org/10.3390/analytica4020019","url":null,"abstract":"This work presents the first development of an analytical turbidimetric method for the determination of legal alcohols in alcohol-based hand sanitizer products. A typical iodoform reaction is exploited to form a yellow product in the form of precipitates. An iodoform test shows a positive result as yellow precipitates in the presence of ethanol and isopropanol; therefore, the test can only be used to distinguish between methanol and those legal alcohols. In the presence of molecular iodine (I2) and a strong alkaline solution, the legal alcohol is converted to the corresponding carbonyl compound (i.e., ethanol to acetaldehyde, isopropanol to acetone). The susceptibility of this intermediate towards the reaction with hydroxide ions (strong alkaline condition) results in formations of yellow precipitation of iodoform (CHI3) and a water-soluble carboxylate salt in the solution. Therefore, this change allows for the detection of legal alcohols through either naked-eye observation (as semi-quantitative analysis) or a common benchtop/portable photometer/spectrophotometer (as quantitative analysis) by means of turbidimetric analysis. In this work, turbidimetry is employed, which is a useful alternative detection method in analytical practice, especially with colored samples in hand sanitizing products. This is because they can employ wavelengths at which the colored solution does not absorb light. As a result of our developed method, the calibration plots are in the range of 30 to 100% (v/v) for both ethanol and isopropanol. The limit of detection (LOD) (3SD of y-intercept/slope) was found to be 7.4% (v/v) ethanol and 6.5% (v/v) isopropanol. Direct analysis of the non-pretreatment of the sample is achieved. The results indicate that our new proposed analytical method is fit for purpose and valid to detect the legal alcohols in alcohol-based hand sanitizing products for both international and Thai regulations (at least 70% (v/v)). Our quantitative results were also comparable to a standard analytical method, such as the use of a gas chromatography-flame ionization detector (GC-FID). Our developed method and analytical operation could potentially be developed into a practically portable analysis.","PeriodicalId":7829,"journal":{"name":"Analytica","volume":"2 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-06-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79751988","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 : 2023-06-08DOI: 10.3390/analytica4020020
A. E. F. Oliveira, S. Pereira, Maurício Resende, L. F. Ferreira
In this study, gold nanoparticles (AuNPs) were synthesized using the Turkevich method. This article explains the didactic step-by-step synthesis, showing pictures of the entire process, including a well-explained mechanism and characterization study. Synthesis involves the reduction of NaAuCl4 using sodium citrate at high temperatures (approximately 90 °C). The two main mechanisms used to explain AuNPs synthesis via the Turkevich method are also discussed. The first mechanism considers that a nanowire intermediary and the other proposes that aggregate intermediates are not formed at any time during the synthesis. The materials (NaAuCl4 and AuNPs) were characterized using UV-Vis spectroscopy, scanning electron microscopy (SEM), atomic force microscopy (AFM), X-ray diffraction (XRD), and dynamic light scattering (DLS). The UV-Vis spectrum exhibits an absorption maximum at 521 nm because of the surface plasmon resonance (SPR) absorption band of the AuNPs. The SEM images of NaAuCl4 show crystals with cubic shapes, while the AuNPs have an average particle size of approximately 16–25 nm and particles that appear mainly spherical. To confirm the particle shapes, AFM was conducted, and it was possible to clearly observe individual spherical nanoparticles and their aggregates, and the average diameter of these AuNPs was approximately 12–19 nm. The XRD pattern of AuNPs showed four main characteristic peaks corresponding to the (111), (200), (220), and (311) planes, confirming the presence of cubic (FCC) gold. The DLS presented an average particle size of 3.3 ± 0.9 nm and a polydispersity index (PDI) of 0.574. AuNPs were synthesized using a simple and rapid method. The resulting spherical and ultra-small particles can be used in several applications.
{"title":"Gold Nanoparticles: A Didactic Step-by-Step of the Synthesis Using the Turkevich Method, Mechanisms, and Characterizations","authors":"A. E. F. Oliveira, S. Pereira, Maurício Resende, L. F. Ferreira","doi":"10.3390/analytica4020020","DOIUrl":"https://doi.org/10.3390/analytica4020020","url":null,"abstract":"In this study, gold nanoparticles (AuNPs) were synthesized using the Turkevich method. This article explains the didactic step-by-step synthesis, showing pictures of the entire process, including a well-explained mechanism and characterization study. Synthesis involves the reduction of NaAuCl4 using sodium citrate at high temperatures (approximately 90 °C). The two main mechanisms used to explain AuNPs synthesis via the Turkevich method are also discussed. The first mechanism considers that a nanowire intermediary and the other proposes that aggregate intermediates are not formed at any time during the synthesis. The materials (NaAuCl4 and AuNPs) were characterized using UV-Vis spectroscopy, scanning electron microscopy (SEM), atomic force microscopy (AFM), X-ray diffraction (XRD), and dynamic light scattering (DLS). The UV-Vis spectrum exhibits an absorption maximum at 521 nm because of the surface plasmon resonance (SPR) absorption band of the AuNPs. The SEM images of NaAuCl4 show crystals with cubic shapes, while the AuNPs have an average particle size of approximately 16–25 nm and particles that appear mainly spherical. To confirm the particle shapes, AFM was conducted, and it was possible to clearly observe individual spherical nanoparticles and their aggregates, and the average diameter of these AuNPs was approximately 12–19 nm. The XRD pattern of AuNPs showed four main characteristic peaks corresponding to the (111), (200), (220), and (311) planes, confirming the presence of cubic (FCC) gold. The DLS presented an average particle size of 3.3 ± 0.9 nm and a polydispersity index (PDI) of 0.574. AuNPs were synthesized using a simple and rapid method. The resulting spherical and ultra-small particles can be used in several applications.","PeriodicalId":7829,"journal":{"name":"Analytica","volume":"36 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-06-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81191465","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 : 2023-06-07DOI: 10.3390/analytica4020018
Esther K. Grosskopf, M. Simmonds, C. Wallis
The resinous wood produced by the Aquilaria and Gyrinops species—agarwood—is both rare and highly valuable. It is used in products from perfumes to medicines and has an estimated global market value of $32 billion. As a result, the adulteration and illegal purchasing of agarwood is widespread and of specific concern to enforcement agencies globally. Therefore, it is of interest to have a fast, reliable, and user-friendly method to confirm the authenticity of a sample of agarwood. We investigated the use of near infrared (NIR) data to develop a method that rapidly distinguished between authentic and non-authentic agarwood samples, based upon a soft independent model of class analogy (SIMCA), using software specific to the application of infrared data to material authentication. The model showed a clear distinction between the authentic and non-authentic samples. However, the small values involved led to poor automatic validation results.
{"title":"Combining Near-Infrared (NIR) Analysis and Modelling as a Fast and Reliable Method to Determine the Authenticity of Agarwood (Aquilaria spp.)","authors":"Esther K. Grosskopf, M. Simmonds, C. Wallis","doi":"10.3390/analytica4020018","DOIUrl":"https://doi.org/10.3390/analytica4020018","url":null,"abstract":"The resinous wood produced by the Aquilaria and Gyrinops species—agarwood—is both rare and highly valuable. It is used in products from perfumes to medicines and has an estimated global market value of $32 billion. As a result, the adulteration and illegal purchasing of agarwood is widespread and of specific concern to enforcement agencies globally. Therefore, it is of interest to have a fast, reliable, and user-friendly method to confirm the authenticity of a sample of agarwood. We investigated the use of near infrared (NIR) data to develop a method that rapidly distinguished between authentic and non-authentic agarwood samples, based upon a soft independent model of class analogy (SIMCA), using software specific to the application of infrared data to material authentication. The model showed a clear distinction between the authentic and non-authentic samples. However, the small values involved led to poor automatic validation results.","PeriodicalId":7829,"journal":{"name":"Analytica","volume":"43 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-06-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83963472","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 : 2023-06-02DOI: 10.3390/analytica4020017
G. Visco, E. Dell’Aglio, M. Tomassetti, Luca Ugo Fontanella, M. Sammartino
Electrical conductivity is one of the main parameters for the characterization of water solutions and for the monitoring of water sources. In this paper, we describe a very inexpensive prototype for conductivity measurements based on Arduino UNO R3 coupled to an open-source circuit board with only passive components. We designed the printed circuit board (PCB) and the suitable handmade cell using stainless-steel electrodes and wrote the freeware management software; the assembly of the prototype, including a temperature probe, and results were relatively simple. In order to allow for replicates, the instrument design, schematics, and software are available with an open-source license. Thirty-one bottles of spring waters with conductivities of between 15.2 and 2000 µS cm−1 were tested using both this prototype and a commercial conductivity meter. Data correlation produced an equation that allowed us to obtain the conductivity value, starting with the value furnished by the Arduino apparatus in arbitrary units. The prototype is accurate enough (inaccuracy lower than 6% excluding very low conductivity values) and precise (RSD% of about 5%). Even if a lot of commercial instruments for conductivity are available, we propose a prototype built with the aim of lowering the cost of measurements, while ensuring that they remain useful for lab or in situ application, as well as for continuous water monitoring/management systems. A further aim was to propose the building of the instrument as a laboratory exercise; this can help students to better understand basic theoretical concepts regarding conductivity, electronic components, and the acquisition and treatment of analytical data.
电导率是表征水溶液和监测水源的主要参数之一。在本文中，我们描述了一种非常便宜的电导率测量原型，该原型基于Arduino UNO R3，与仅含无源元件的开源电路板耦合。采用不锈钢电极设计了印刷电路板(PCB)和合适的手工电池，并编写了免费的管理软件;原型机的组装，包括一个温度探头，结果都比较简单。为了允许复制，仪器设计、原理图和软件可以通过开源许可获得。使用该原型和商用电导率仪对31瓶电导率在15.2至2000µS cm - 1之间的泉水进行了测试。数据关联产生一个方程，使我们能够获得电导率值，从Arduino设备提供的任意单位的值开始。原型足够准确(不包括非常低的电导率值，不准确性低于6%)和精确(RSD%约为5%)。即使有很多商业电导率仪器可用，我们也提出了一个原型，旨在降低测量成本，同时确保它们对实验室或现场应用以及连续水监测/管理系统仍然有用。进一步的目标是建议将仪器作为实验室的练习;这可以帮助学生更好地理解有关电导率、电子元件以及分析数据的获取和处理的基本理论概念。
{"title":"An Open-Source, Low-Cost Apparatus for Conductivity Measurements Based on Arduino and Coupled to a Handmade Cell","authors":"G. Visco, E. Dell’Aglio, M. Tomassetti, Luca Ugo Fontanella, M. Sammartino","doi":"10.3390/analytica4020017","DOIUrl":"https://doi.org/10.3390/analytica4020017","url":null,"abstract":"Electrical conductivity is one of the main parameters for the characterization of water solutions and for the monitoring of water sources. In this paper, we describe a very inexpensive prototype for conductivity measurements based on Arduino UNO R3 coupled to an open-source circuit board with only passive components. We designed the printed circuit board (PCB) and the suitable handmade cell using stainless-steel electrodes and wrote the freeware management software; the assembly of the prototype, including a temperature probe, and results were relatively simple. In order to allow for replicates, the instrument design, schematics, and software are available with an open-source license. Thirty-one bottles of spring waters with conductivities of between 15.2 and 2000 µS cm−1 were tested using both this prototype and a commercial conductivity meter. Data correlation produced an equation that allowed us to obtain the conductivity value, starting with the value furnished by the Arduino apparatus in arbitrary units. The prototype is accurate enough (inaccuracy lower than 6% excluding very low conductivity values) and precise (RSD% of about 5%). Even if a lot of commercial instruments for conductivity are available, we propose a prototype built with the aim of lowering the cost of measurements, while ensuring that they remain useful for lab or in situ application, as well as for continuous water monitoring/management systems. A further aim was to propose the building of the instrument as a laboratory exercise; this can help students to better understand basic theoretical concepts regarding conductivity, electronic components, and the acquisition and treatment of analytical data.","PeriodicalId":7829,"journal":{"name":"Analytica","volume":"22 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-06-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77111648","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 : 2023-05-22DOI: 10.3390/analytica4020016
Vidia A Gokool, Janet Crespo-Cajigas, A. Ramírez Torres, Liam Forsythe, Benjamin S. Abella, Howard K. Holness, A. T. C. Johnson, Richard Postrel, K. Furton
The adaptable nature of the SARS-CoV-2 virus has led to the emergence of multiple viral variants of concern. This research builds upon a previous demonstration of sampling human hand odor to distinguish SARS-CoV-2 infection status in order to incorporate considerations of the disease variants. This study demonstrates the ability of human odor expression to be implemented as a non-invasive medium for the differentiation of SARS-CoV-2 variants. Volatile organic compounds (VOCs) were extracted from SARS-CoV-2-positive samples using solid phase microextraction (SPME) coupled with gas chromatography–mass spectrometry (GC–MS). Sparse partial least squares discriminant analysis (sPLS-DA) modeling revealed that supervised machine learning could be used to predict the variant identity of a sample using VOC expression alone. The class discrimination of Delta and Omicron BA.5 variant samples was performed with 95.2% (±0.4) accuracy. Omicron BA.2 and Omicron BA.5 variants were correctly classified with 78.5% (±0.8) accuracy. Lastly, Delta and Omicron BA.2 samples were assigned with 71.2% (±1.0) accuracy. This work builds upon the framework of non-invasive techniques producing diagnostics through the analysis of human odor expression, all in support of public health monitoring.
{"title":"Predicting SARS-CoV-2 Variant Using Non-Invasive Hand Odor Analysis: A Pilot Study","authors":"Vidia A Gokool, Janet Crespo-Cajigas, A. Ramírez Torres, Liam Forsythe, Benjamin S. Abella, Howard K. Holness, A. T. C. Johnson, Richard Postrel, K. Furton","doi":"10.3390/analytica4020016","DOIUrl":"https://doi.org/10.3390/analytica4020016","url":null,"abstract":"The adaptable nature of the SARS-CoV-2 virus has led to the emergence of multiple viral variants of concern. This research builds upon a previous demonstration of sampling human hand odor to distinguish SARS-CoV-2 infection status in order to incorporate considerations of the disease variants. This study demonstrates the ability of human odor expression to be implemented as a non-invasive medium for the differentiation of SARS-CoV-2 variants. Volatile organic compounds (VOCs) were extracted from SARS-CoV-2-positive samples using solid phase microextraction (SPME) coupled with gas chromatography–mass spectrometry (GC–MS). Sparse partial least squares discriminant analysis (sPLS-DA) modeling revealed that supervised machine learning could be used to predict the variant identity of a sample using VOC expression alone. The class discrimination of Delta and Omicron BA.5 variant samples was performed with 95.2% (±0.4) accuracy. Omicron BA.2 and Omicron BA.5 variants were correctly classified with 78.5% (±0.8) accuracy. Lastly, Delta and Omicron BA.2 samples were assigned with 71.2% (±1.0) accuracy. This work builds upon the framework of non-invasive techniques producing diagnostics through the analysis of human odor expression, all in support of public health monitoring.","PeriodicalId":7829,"journal":{"name":"Analytica","volume":"52 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85578227","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 : 2023-05-20DOI: 10.3390/analytica4020015
D. Lachos‐Perez, J. C. Martins-Vieira, Juliano Missau, Kumari Anshu, O. K. Siakpebru, Sonal K. Thengane, A. Morais, E. Tanabe, D. Bertuol
This review provides insights into the current research on pyrolytic bio-oil obtained from different feedstock regarding upgrading techniques and applications such as energy, fuels, chemicals, and carbon materials. Raw bio-oil is not appropriate for transportation and ignition due to undesired properties; therefore, several challenges have been reported regarding its suitable market application. For liquid biofuel production, thermochemical pathways, particularly hydrogenation and deoxygenation, must be carried out, and for chemical production, liquid solvents are mostly used via physical separation. The main issues related to downstream processes with environmental and economic assessment are also covered. The analysis indicates that the major bottlenecks for commercial applications of upgraded bio-oil are the initial stage (upgrading techniques), high production costs, and pilot scale production. Finally, future directions are addressed for the improvement of bio-oil upgrading.
{"title":"Review on Biomass Pyrolysis with a Focus on Bio-Oil Upgrading Techniques","authors":"D. Lachos‐Perez, J. C. Martins-Vieira, Juliano Missau, Kumari Anshu, O. K. Siakpebru, Sonal K. Thengane, A. Morais, E. Tanabe, D. Bertuol","doi":"10.3390/analytica4020015","DOIUrl":"https://doi.org/10.3390/analytica4020015","url":null,"abstract":"This review provides insights into the current research on pyrolytic bio-oil obtained from different feedstock regarding upgrading techniques and applications such as energy, fuels, chemicals, and carbon materials. Raw bio-oil is not appropriate for transportation and ignition due to undesired properties; therefore, several challenges have been reported regarding its suitable market application. For liquid biofuel production, thermochemical pathways, particularly hydrogenation and deoxygenation, must be carried out, and for chemical production, liquid solvents are mostly used via physical separation. The main issues related to downstream processes with environmental and economic assessment are also covered. The analysis indicates that the major bottlenecks for commercial applications of upgraded bio-oil are the initial stage (upgrading techniques), high production costs, and pilot scale production. Finally, future directions are addressed for the improvement of bio-oil upgrading.","PeriodicalId":7829,"journal":{"name":"Analytica","volume":"51 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87448871","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}
Achieving quantification of biomarkers in body fluids is crucial to the indication of the state of a person’s body and health. Wearable sensors could offer a convenient, fast and painless sensing strategy. In this work, we fabricated a wearable electrochemical patch sensor for simultaneous detection of dopamine and glucose in sweat. The sensor was printed on a flexible PDMS substrate with a simple screen-printed method. This prepared four-electrode sensor integrated two working electrodes for dopamine and glucose electrochemical sensing, one Ag/AgCl reference electrode and one carbon counter electrode, respectively. Cyclic voltammetry, differential pulse voltammetry and chronoamperometry were used for the evaluation of the wearable electrochemical patch sensor. It exhibits good sensitivity, wide linear range, low limit of detection, good anti-interference and reproducibility toward dopamine and glucose sensing in PBS and sweat.
{"title":"A Wearable Patch Sensor for Simultaneous Detection of Dopamine and Glucose in Sweat","authors":"Yue Sun, Junjie Ma, Yuwei Wang, Sen Qiao, Yihao Feng, Zhanhong Li, Zifeng Wang, Yutong Han, Zhigang Zhu","doi":"10.3390/analytica4020014","DOIUrl":"https://doi.org/10.3390/analytica4020014","url":null,"abstract":"Achieving quantification of biomarkers in body fluids is crucial to the indication of the state of a person’s body and health. Wearable sensors could offer a convenient, fast and painless sensing strategy. In this work, we fabricated a wearable electrochemical patch sensor for simultaneous detection of dopamine and glucose in sweat. The sensor was printed on a flexible PDMS substrate with a simple screen-printed method. This prepared four-electrode sensor integrated two working electrodes for dopamine and glucose electrochemical sensing, one Ag/AgCl reference electrode and one carbon counter electrode, respectively. Cyclic voltammetry, differential pulse voltammetry and chronoamperometry were used for the evaluation of the wearable electrochemical patch sensor. It exhibits good sensitivity, wide linear range, low limit of detection, good anti-interference and reproducibility toward dopamine and glucose sensing in PBS and sweat.","PeriodicalId":7829,"journal":{"name":"Analytica","volume":"25 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-05-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85344719","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 : 2023-05-01DOI: 10.3390/analytica4020013
M. Feitosa, Anderson M. Santos, Ademar Wong, R. S. Rocha, F. Moraes
This work proposes a simple, fast and low-cost voltammetric method for the determination of trimethoprim at low concentrations in an analytical and real matrix (river water sample, bovine serum and synthetic urine). For this, a glassy carbon electrode was modified with Printex(6L) carbon and gold nanoparticles in a chitosan film crosslinked with epichlorohydrin. After that, the electrochemical measurement system contained a solution of phosphate buffer at pH 4.0 with commands for the square wave voltammetry technique. The results achieved showed a limit of detection equal to 12.4 nmol L−1 and a linear concentration range from 0.20 to 6.0 μmol L−1. The sensor selectivity was tested in the presence of various electroactive molecules, and the results showed that the detection of TMP in the presence of possible interferents was not masked. In addition, the applicability of the AuNPs–Printex(6L)–CTS:EPH/GCE sensor was also verified in synthetic samples of urine, bovine serum and river water through standard addition and recovery tests. Finally, the results of this analytical proposal portray a simple, fast and efficient method for the detection of TMP in different matrices.
{"title":"Voltammetric Determination of Trimethoprim Using a Glassy Carbon Electrode Modified with Printex(6L) Carbon and Gold Nanoparticles","authors":"M. Feitosa, Anderson M. Santos, Ademar Wong, R. S. Rocha, F. Moraes","doi":"10.3390/analytica4020013","DOIUrl":"https://doi.org/10.3390/analytica4020013","url":null,"abstract":"This work proposes a simple, fast and low-cost voltammetric method for the determination of trimethoprim at low concentrations in an analytical and real matrix (river water sample, bovine serum and synthetic urine). For this, a glassy carbon electrode was modified with Printex(6L) carbon and gold nanoparticles in a chitosan film crosslinked with epichlorohydrin. After that, the electrochemical measurement system contained a solution of phosphate buffer at pH 4.0 with commands for the square wave voltammetry technique. The results achieved showed a limit of detection equal to 12.4 nmol L−1 and a linear concentration range from 0.20 to 6.0 μmol L−1. The sensor selectivity was tested in the presence of various electroactive molecules, and the results showed that the detection of TMP in the presence of possible interferents was not masked. In addition, the applicability of the AuNPs–Printex(6L)–CTS:EPH/GCE sensor was also verified in synthetic samples of urine, bovine serum and river water through standard addition and recovery tests. Finally, the results of this analytical proposal portray a simple, fast and efficient method for the detection of TMP in different matrices.","PeriodicalId":7829,"journal":{"name":"Analytica","volume":"8 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80472656","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 : 2023-04-30DOI: 10.3390/analytica4020012
R. T. Pessoa, I. S. Alcântara, Lucas Yure Santos da Silva, R. S. Costa, Tarcísio Mendes Silva, C. D. M. Oliveira-Tintino, A. G. B. Ramos, M. R. C. Oliveira, A. O. Martins, B. C. G. V. D. Lacerda, Edlane Martins de Andrade, J. Ribeiro-Filho, C. M. Lima, H. Coutinho, I. A. Menezes
Ximenia americana L., popularly known in Brazil as “ameixa do-mato, ameixa-brava, and ameixa-do-sertão,” is widely used in folk medicine to treat several intestinal disorders. The present study assessed the potential mechanisms of action underlying the gastroprotective activity of the hydroethanolic extract of Ximenia americana L. (EHXA) stem bark. The acute toxicity of EHXA was estimated, and later, the gastroprotective effect in mice was assessed through acute models of gastric lesions induced by acidified or absolute ethanol and indomethacin, where the following mechanisms were pharmacologically analyzed: the involvement of prostaglandins (PG), histamine (H2) receptors, ATP-dependent potassium channels, sulfhydryl groups (SH), α2 adrenergic receptors, nitric oxide (NO), myeloperoxidase (MPO), gastric mucus production, and acetylcholine-mediated intestinal motility. Regarding toxicity, EHXA did not cause deaths or signs of toxicity (LD50 greater than or equal to 2000 mg/kg/p.o.). When the gastroprotective effect was assessed, EHXA (50, 100, and 200 mg/kg/p.o.) reduced the rate of lesions induced by acidified ethanol by 65.63; 53.66, and 58.02% in absolute ethanol at 88.91, 78.82, and 74.68%, respectively, when compared to the negative control group. In the indomethacin-induced gastric injury model, the reductions were 84.69, 55.99, 55.99, and 42.50%, respectively. The study revealed that EHXA might stimulate mucus production and reduce intestinal motility through SH groups, NO production, and activation of α2 adrenergic receptors. The results indicated that EHXA had significant gastroprotective activity in the evaluated models. However, further investigation is required to elucidate the cellular and molecular events underlying the action of EHXA components and to correlate them with the modulation of the signaling pathways, as demonstrated by the current pharmacological approach. Therefore, the results demonstrated in the present study, as well as previously reported findings, support the recommendation of using this species in traditional communities in Brazil.
美洲西米尼亚，在巴西被称为“美洲西米尼亚-马托、美洲西米尼亚-布拉瓦和美洲西米尼亚- sert”，在民间医学中被广泛用于治疗几种肠道疾病。本研究评估了西menia americana L. (EHXA)茎皮氢乙醇提取物胃保护活性的潜在作用机制。评估EHXA的急性毒性，然后通过酸化或无水乙醇和吲哚美辛致小鼠急性胃损伤模型，评估其胃保护作用，药理学分析其机制如下:前列腺素(PG)、组胺(H2)受体、atp依赖性钾通道、巯基(SH)、α2肾上腺素能受体、一氧化氮(NO)、髓过氧化物酶(MPO)、胃粘液生成和乙酰胆碱介导的肠道运动的参与。关于毒性，EHXA没有造成死亡或毒性迹象(LD50大于或等于2000 mg/kg/p.o)。当评估胃保护作用时，EHXA(50、100和200 mg/kg/p.o)使酸化乙醇引起的病变率降低了65.63%;与阴性对照组相比，无水乙醇含量分别为88.91、78.82、74.68%，分别为53.66、58.02%。在吲哚美辛致胃损伤模型中，分别减少84.69%、55.99%、55.99%和42.50%。研究发现EHXA可能通过SH组、NO的产生和α2肾上腺素能受体的激活来刺激黏液的产生，降低肠道蠕动。结果表明，EHXA在评价模型中具有显著的胃保护作用。然而，需要进一步的研究来阐明EHXA成分作用背后的细胞和分子事件，并将它们与信号通路的调节联系起来，正如目前的药理学方法所证明的那样。因此，本研究的结果以及先前报道的结果支持在巴西传统社区使用该物种的建议。
{"title":"Ximenia americana L.: Chemical Characterization and Gastroprotective Effect","authors":"R. T. Pessoa, I. S. Alcântara, Lucas Yure Santos da Silva, R. S. Costa, Tarcísio Mendes Silva, C. D. M. Oliveira-Tintino, A. G. B. Ramos, M. R. C. Oliveira, A. O. Martins, B. C. G. V. D. Lacerda, Edlane Martins de Andrade, J. Ribeiro-Filho, C. M. Lima, H. Coutinho, I. A. Menezes","doi":"10.3390/analytica4020012","DOIUrl":"https://doi.org/10.3390/analytica4020012","url":null,"abstract":"Ximenia americana L., popularly known in Brazil as “ameixa do-mato, ameixa-brava, and ameixa-do-sertão,” is widely used in folk medicine to treat several intestinal disorders. The present study assessed the potential mechanisms of action underlying the gastroprotective activity of the hydroethanolic extract of Ximenia americana L. (EHXA) stem bark. The acute toxicity of EHXA was estimated, and later, the gastroprotective effect in mice was assessed through acute models of gastric lesions induced by acidified or absolute ethanol and indomethacin, where the following mechanisms were pharmacologically analyzed: the involvement of prostaglandins (PG), histamine (H2) receptors, ATP-dependent potassium channels, sulfhydryl groups (SH), α2 adrenergic receptors, nitric oxide (NO), myeloperoxidase (MPO), gastric mucus production, and acetylcholine-mediated intestinal motility. Regarding toxicity, EHXA did not cause deaths or signs of toxicity (LD50 greater than or equal to 2000 mg/kg/p.o.). When the gastroprotective effect was assessed, EHXA (50, 100, and 200 mg/kg/p.o.) reduced the rate of lesions induced by acidified ethanol by 65.63; 53.66, and 58.02% in absolute ethanol at 88.91, 78.82, and 74.68%, respectively, when compared to the negative control group. In the indomethacin-induced gastric injury model, the reductions were 84.69, 55.99, 55.99, and 42.50%, respectively. The study revealed that EHXA might stimulate mucus production and reduce intestinal motility through SH groups, NO production, and activation of α2 adrenergic receptors. The results indicated that EHXA had significant gastroprotective activity in the evaluated models. However, further investigation is required to elucidate the cellular and molecular events underlying the action of EHXA components and to correlate them with the modulation of the signaling pathways, as demonstrated by the current pharmacological approach. Therefore, the results demonstrated in the present study, as well as previously reported findings, support the recommendation of using this species in traditional communities in Brazil.","PeriodicalId":7829,"journal":{"name":"Analytica","volume":"43 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75588273","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 : 2023-04-24DOI: 10.3390/analytica4020011
I. L. D. de Macêdo, N. Dupuy, Vitor H. dos S. Brito, E. Gil, G. Silva, E. K. Moreno, I. Demiate, M. Cereda
Different starch properties may cause alterations in the foodstuff’s external appearance. However, modification processes in starches are usually secretive. The use of chemically modified starches is regulated by international standards, which makes it important to identify its presence and type. Mid-infrared spectroscopy (MIR)-modified starches’ identification can be hindered by the presence of excess glucose. This research investigates types of modification in commercial starches and in approaches that circumvent MIR’s limitations with exploratory analysis. It also considers that enzymatic hydrolysis (α-amylase and amyloglucosidase) can highlight the points of modification in the structure, which can be detected with infrared assays. To determine if sour cassava starch (FCS) is modified and check its type, six samples were selected: a native one, three of the most common cassava modified starches (etherified, esterified, and FCS), and two laboratory processed samples (Acid, Oxidized). The results showed that the sour cassava starch showed similarities with a commercial ester and an oxidized cassava starch, which may be due to the formation of a graft, corresponding to what the literature has already reported for corn starch treated with lactic acid and gamma radiation.
{"title":"Modified Cassava Starches’ Identification through Mid-Infrared Spectroscopy and Exploratory Analysis","authors":"I. L. D. de Macêdo, N. Dupuy, Vitor H. dos S. Brito, E. Gil, G. Silva, E. K. Moreno, I. Demiate, M. Cereda","doi":"10.3390/analytica4020011","DOIUrl":"https://doi.org/10.3390/analytica4020011","url":null,"abstract":"Different starch properties may cause alterations in the foodstuff’s external appearance. However, modification processes in starches are usually secretive. The use of chemically modified starches is regulated by international standards, which makes it important to identify its presence and type. Mid-infrared spectroscopy (MIR)-modified starches’ identification can be hindered by the presence of excess glucose. This research investigates types of modification in commercial starches and in approaches that circumvent MIR’s limitations with exploratory analysis. It also considers that enzymatic hydrolysis (α-amylase and amyloglucosidase) can highlight the points of modification in the structure, which can be detected with infrared assays. To determine if sour cassava starch (FCS) is modified and check its type, six samples were selected: a native one, three of the most common cassava modified starches (etherified, esterified, and FCS), and two laboratory processed samples (Acid, Oxidized). The results showed that the sour cassava starch showed similarities with a commercial ester and an oxidized cassava starch, which may be due to the formation of a graft, corresponding to what the literature has already reported for corn starch treated with lactic acid and gamma radiation.","PeriodicalId":7829,"journal":{"name":"Analytica","volume":"39 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86779159","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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