Pub Date : 2024-07-15DOI: 10.3390/analytica5030021
Alaa M. Younis, Sayed M. Saleh, A. Albadri, E. Elkady
This study focuses on the biosorption of harmful metals from aqueous solutions using Enteromorpha compressa macroalgal biomass nanoparticles as the biosorbent. Scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and X-ray diffraction analysis (XRD) were employed to characterize the biosorbent. The effects of pH, initial metal ion concentration, biosorbent dosage, and contact time on the biosorption process were investigated. The maximum biosorption capacity for metals was observed at a pH of 5.0. The experimental equilibrium data were analyzed using three-parameter isotherm models, namely Freundlich, Temkin, and Langmuir equations, which provided better fits for the equilibrium data. A contact time of approximately 120 min was required to achieve biosorption equilibrium for various initial metal concentrations. Cr(III), Co(II), Ni(II), Cu(II), and Cd(II) demonstrated distinct maximum biosorption capacities of 24.99375 mg/g, 25.06894 mg/g, 24.55796 mg/g, 24.97502 mg/g, and 25.3936 mg/g, respectively. Different kinetic models were applied to fit the kinetic data, including intraparticle diffusion, pseudo-second-order, and pseudo-first-order versions. The pseudo-second-order model showed good agreement with the experimental results, indicating its suitability for describing the kinetics of the biosorption process. Based on these findings, it can be stated that E. compressa nanoparticle demonstrates potential as an effective biosorbent for removing targeted metals from water.
{"title":"Enteromorpha compressa Macroalgal Biomass Nanoparticles as Eco-Friendly Biosorbents for the Efficient Removal of Harmful Metals from Aqueous Solutions","authors":"Alaa M. Younis, Sayed M. Saleh, A. Albadri, E. Elkady","doi":"10.3390/analytica5030021","DOIUrl":"https://doi.org/10.3390/analytica5030021","url":null,"abstract":"This study focuses on the biosorption of harmful metals from aqueous solutions using Enteromorpha compressa macroalgal biomass nanoparticles as the biosorbent. Scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and X-ray diffraction analysis (XRD) were employed to characterize the biosorbent. The effects of pH, initial metal ion concentration, biosorbent dosage, and contact time on the biosorption process were investigated. The maximum biosorption capacity for metals was observed at a pH of 5.0. The experimental equilibrium data were analyzed using three-parameter isotherm models, namely Freundlich, Temkin, and Langmuir equations, which provided better fits for the equilibrium data. A contact time of approximately 120 min was required to achieve biosorption equilibrium for various initial metal concentrations. Cr(III), Co(II), Ni(II), Cu(II), and Cd(II) demonstrated distinct maximum biosorption capacities of 24.99375 mg/g, 25.06894 mg/g, 24.55796 mg/g, 24.97502 mg/g, and 25.3936 mg/g, respectively. Different kinetic models were applied to fit the kinetic data, including intraparticle diffusion, pseudo-second-order, and pseudo-first-order versions. The pseudo-second-order model showed good agreement with the experimental results, indicating its suitability for describing the kinetics of the biosorption process. Based on these findings, it can be stated that E. compressa nanoparticle demonstrates potential as an effective biosorbent for removing targeted metals from water.","PeriodicalId":7829,"journal":{"name":"Analytica","volume":"18 3","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141646378","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 : 2024-07-09DOI: 10.3390/analytica5030020
Veronica D’Eusanio
Watermelon suffers substantial post-harvest losses owing to strict quality standards, resulting in 20–30% of the crop being left unharvested. This study investigated the potential of valorizing dried watermelon pomace (DWP), a byproduct of watermelon juice extraction, focusing on its lycopene content—a potent antioxidant. This study assessed lycopene stability in DWP from four watermelon cultivars (Perla Nera®, Gavina®, Crimson Sweet, and Asahi Miyako) under different storage conditions (vial-sealed and vacuum-sealed). The lycopene content in freshly prepared DWP samples ranged from 0.734 to 1.572 mg/g db. The results indicated that vacuum-sealed samples exhibited significantly slower lycopene degradation than vial-sealed samples, highlighting the impact of air exposure on lycopene stability. After 90 days of storage, lycopene content in vacuum-sealed samples ranged from 0.214 to 1.234 mg/g db, while that in vial-sealed samples ranged from 0.013 to 0.731 mg/g db. Furthermore, this study assessed the effect of pretreatments with ascorbic acid (pretreatment A) and a mixture of ascorbic and citric acids (pretreatment B) on lycopene stability. Pretreatment B showed superior effectiveness, yielding higher lycopene levels than pretreatment A (p < 0.05). The stabilizing effects of ascorbic acid and citric acid were attributed to their antioxidant properties and their roles as pH regulators and chelators.
由于严格的质量标准，西瓜在收获后损失惨重，导致 20-30% 的西瓜未被收获。本研究调查了西瓜榨汁的副产品--干西瓜渣（DWP）的增值潜力，重点关注其番茄红素含量--一种有效的抗氧化剂。本研究评估了四个西瓜品种（Perla Nera®、Gavina®、Crimson Sweet 和 Asahi Miyako）的西瓜干渣在不同储存条件（小瓶密封和真空密封）下番茄红素的稳定性。新鲜制备的 DWP 样品中番茄红素的含量介于 0.734 至 1.572 毫克/克 db 之间。结果表明，真空密封样品的番茄红素降解速度明显慢于小瓶密封样品，凸显了空气暴露对番茄红素稳定性的影响。贮藏 90 天后，真空密封样品中的番茄红素含量介于 0.214 至 1.234 毫克/克 db 之间，而小瓶密封样品中的番茄红素含量介于 0.013 至 0.731 毫克/克 db 之间。此外，本研究还评估了抗坏血酸预处理（预处理 A）和抗坏血酸与柠檬酸混合物预处理（预处理 B）对番茄红素稳定性的影响。与预处理 A 相比，预处理 B 的效果更佳，番茄红素含量更高（p < 0.05）。抗坏血酸和柠檬酸的稳定作用归因于它们的抗氧化特性以及作为 pH 值调节剂和螯合剂的作用。
{"title":"Assessment of Lycopene Levels in Dried Watermelon Pomace: A Sustainable Approach to Waste Reduction and Nutrient Valorization","authors":"Veronica D’Eusanio","doi":"10.3390/analytica5030020","DOIUrl":"https://doi.org/10.3390/analytica5030020","url":null,"abstract":"Watermelon suffers substantial post-harvest losses owing to strict quality standards, resulting in 20–30% of the crop being left unharvested. This study investigated the potential of valorizing dried watermelon pomace (DWP), a byproduct of watermelon juice extraction, focusing on its lycopene content—a potent antioxidant. This study assessed lycopene stability in DWP from four watermelon cultivars (Perla Nera®, Gavina®, Crimson Sweet, and Asahi Miyako) under different storage conditions (vial-sealed and vacuum-sealed). The lycopene content in freshly prepared DWP samples ranged from 0.734 to 1.572 mg/g db. The results indicated that vacuum-sealed samples exhibited significantly slower lycopene degradation than vial-sealed samples, highlighting the impact of air exposure on lycopene stability. After 90 days of storage, lycopene content in vacuum-sealed samples ranged from 0.214 to 1.234 mg/g db, while that in vial-sealed samples ranged from 0.013 to 0.731 mg/g db. Furthermore, this study assessed the effect of pretreatments with ascorbic acid (pretreatment A) and a mixture of ascorbic and citric acids (pretreatment B) on lycopene stability. Pretreatment B showed superior effectiveness, yielding higher lycopene levels than pretreatment A (p < 0.05). The stabilizing effects of ascorbic acid and citric acid were attributed to their antioxidant properties and their roles as pH regulators and chelators.","PeriodicalId":7829,"journal":{"name":"Analytica","volume":"37 21","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141663742","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 : 2024-07-07DOI: 10.3390/analytica5030019
Janet Crespo-Cajigas, A. Kabir, K. Furton, Lauryn E. DeGreeff
Contamination of trace levels of volatile organic compounds (VOCs) in enclosed spaces is not usually a significant cause for concern; however, it can be relevant in the case of canine scent detection training as a canine’s superior sense of smell makes them highly likely to detect low levels of contamination, contributing to inefficient training. Thus, herein, we address the need for a simple, low-cost, robust, vapochromic sensor to determine the cross-contamination of VOCs within closed containers, such as canine training aid kits. This study focuses on the development of a vapor sensor, which produces a rapid colorimetric change when a target chemical vapor is present. A pH indicator is used as the colorimetric dye and its incorporation into a sol–gel matrix on a paper substrate is confirmed via SEM characterization. The sensor’s stability and performance is tested against exposure to various levels of sunlight and temperature. The design allows the sensor to present a clear and unambiguous visible response to the release of the volatile target within a closed container. It can be readily incorporated into existing training kits and functions as a straightforward reminder of when training aids need to be changed or a new containment system should be considered.
{"title":"Development of a Paper-Based Sol–Gel Vapochromic Sensor for the Detection of Vapor Cross-Contamination within a Closed Container","authors":"Janet Crespo-Cajigas, A. Kabir, K. Furton, Lauryn E. DeGreeff","doi":"10.3390/analytica5030019","DOIUrl":"https://doi.org/10.3390/analytica5030019","url":null,"abstract":"Contamination of trace levels of volatile organic compounds (VOCs) in enclosed spaces is not usually a significant cause for concern; however, it can be relevant in the case of canine scent detection training as a canine’s superior sense of smell makes them highly likely to detect low levels of contamination, contributing to inefficient training. Thus, herein, we address the need for a simple, low-cost, robust, vapochromic sensor to determine the cross-contamination of VOCs within closed containers, such as canine training aid kits. This study focuses on the development of a vapor sensor, which produces a rapid colorimetric change when a target chemical vapor is present. A pH indicator is used as the colorimetric dye and its incorporation into a sol–gel matrix on a paper substrate is confirmed via SEM characterization. The sensor’s stability and performance is tested against exposure to various levels of sunlight and temperature. The design allows the sensor to present a clear and unambiguous visible response to the release of the volatile target within a closed container. It can be readily incorporated into existing training kits and functions as a straightforward reminder of when training aids need to be changed or a new containment system should be considered.","PeriodicalId":7829,"journal":{"name":"Analytica","volume":" 2","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141670499","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 : 2024-06-14DOI: 10.3390/analytica5020018
Moussa Nid Ahmed, Jamila Gagour, Abderrahim Asbbane, Otmane Hallouch, Lahoucine Atrach, A. Giuffré, Khalid Majourhat, S. Gharby
The present investigation was performed to evaluate the effects of various synthetic antioxidants (vitamin A, vitamin E, β-carotene, and BHT) on the oxidation of sunflower oil subjected to accelerated thermal storage at 60 °C for three months (12 weeks). The performance of the antioxidants studied was evaluated using several quality parameters: the free fatty acid value (FFA), primary oxidation (via the peroxide value (PV) and K232 value), secondary oxidation products (via the anisidine value (p-AV) and K270 value), and the total oxidation value (TOTOX). The fatty acid composition (FAC), oxidizability value (COX), iodine value (IV), and pigment content (chlorophyll and carotenoid) were also evaluated. The results revealed that the control sample of sunflower oil exhibited higher susceptibility to oxidative deterioration. Antioxidants at 200 ppm were more effective in preserving the oxidative stability of sunflower oil subjected to accelerated storage compared to the control oil. The smallest increases in all stability parameter indexes were recorded for antioxidant-supplemented sunflower oil. However, the IV and chlorophyll and carotenoid contents were reduced. At 200 ppm, vitamin E and β-carotene showed the greatest stability in sunflower oil, while their combination with vitamin A at 100 ppm of each showed the lowest stability. In addition, synthetic antioxidants provided greater protection against the degradation of polyunsaturated fatty acids (PUFAs). The highest level of PUFA degradation was recorded in the control oil, followed by the oil containing vitamin A. In conclusion, adding synthetic antioxidants to sunflower oil improves its stability during storage. However, some authors associated these molecules with a health risk due to carcinogenic effects as these molecules have been listed as “Generally Recognized As Safe” (GRAS).
本研究旨在评估各种合成抗氧化剂（维生素 A、维生素 E、β-胡萝卜素和 BHT）对在 60 °C 下加速热贮存三个月（12 周）的葵花籽油氧化作用的影响。所研究的抗氧化剂的性能是通过几个质量参数来评估的：游离脂肪酸值（FFA）、一次氧化（通过过氧化值（PV）和 K232 值）、二次氧化产物（通过甲氧基苯胺值（p-AV）和 K270 值）以及总氧化值（TOTOX）。此外，还评估了脂肪酸组成（FAC）、氧化值（COX）、碘值（IV）和色素含量（叶绿素和类胡萝卜素）。结果显示，葵花籽油的对照样本更容易氧化变质。与对照油相比，200 ppm 的抗氧化剂能更有效地保持加速储存葵花籽油的氧化稳定性。添加了抗氧化剂的葵花籽油在所有稳定性参数指标方面的增幅都最小。不过，IV 值、叶绿素和类胡萝卜素含量有所降低。维生素 E 和 β-胡萝卜素含量为 200 ppm 时，在葵花籽油中的稳定性最高，而它们与维生素 A 的组合含量为 100 ppm 时，在葵花籽油中的稳定性最低。此外，合成抗氧化剂能更好地防止多不饱和脂肪酸（PUFA）降解。总之，在葵花籽油中添加合成抗氧化剂可提高其在储藏期间的稳定性。不过，一些作者认为这些分子具有致癌作用，可能会危及健康，因为这些分子已被列为 "公认安全"（GRAS）。
{"title":"Advances in the Use of Four Synthetic Antioxidants as Food Additives for Enhancing the Oxidative Stability of Refined Sunflower Oil (Helianthus annuus L.)","authors":"Moussa Nid Ahmed, Jamila Gagour, Abderrahim Asbbane, Otmane Hallouch, Lahoucine Atrach, A. Giuffré, Khalid Majourhat, S. Gharby","doi":"10.3390/analytica5020018","DOIUrl":"https://doi.org/10.3390/analytica5020018","url":null,"abstract":"The present investigation was performed to evaluate the effects of various synthetic antioxidants (vitamin A, vitamin E, β-carotene, and BHT) on the oxidation of sunflower oil subjected to accelerated thermal storage at 60 °C for three months (12 weeks). The performance of the antioxidants studied was evaluated using several quality parameters: the free fatty acid value (FFA), primary oxidation (via the peroxide value (PV) and K232 value), secondary oxidation products (via the anisidine value (p-AV) and K270 value), and the total oxidation value (TOTOX). The fatty acid composition (FAC), oxidizability value (COX), iodine value (IV), and pigment content (chlorophyll and carotenoid) were also evaluated. The results revealed that the control sample of sunflower oil exhibited higher susceptibility to oxidative deterioration. Antioxidants at 200 ppm were more effective in preserving the oxidative stability of sunflower oil subjected to accelerated storage compared to the control oil. The smallest increases in all stability parameter indexes were recorded for antioxidant-supplemented sunflower oil. However, the IV and chlorophyll and carotenoid contents were reduced. At 200 ppm, vitamin E and β-carotene showed the greatest stability in sunflower oil, while their combination with vitamin A at 100 ppm of each showed the lowest stability. In addition, synthetic antioxidants provided greater protection against the degradation of polyunsaturated fatty acids (PUFAs). The highest level of PUFA degradation was recorded in the control oil, followed by the oil containing vitamin A. In conclusion, adding synthetic antioxidants to sunflower oil improves its stability during storage. However, some authors associated these molecules with a health risk due to carcinogenic effects as these molecules have been listed as “Generally Recognized As Safe” (GRAS).","PeriodicalId":7829,"journal":{"name":"Analytica","volume":"61 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-06-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141338449","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 : 2024-06-04DOI: 10.3390/analytica5020017
Norihiro Otani, Yasuharu Kanki, Kieu D. M. Nguyen, T. Sugasawa
Rapid advancements in gene technology have raised concerns regarding the potential abuse of techniques, such as gene doping, for enhancing athletic performance. To identify this possibility, a reliable procedure for detecting doping genes is required. Although detection methods for doping genes have been created, there are still areas for further improvement. One significant challenge is the high storage and transport costs of the test samples. For this issue, the dried blood spot (DBS) method can be a cost-effective solution. This study aimed to assess the practicality of incorporating DBSs into the gene doping detection process as a pilot study. Whole-blood samples were initially collected from mice engineered to express human erythropoietin from the rAAV vector. Then, the blood was placed in filter papers and left to dry at room temperature for five hours to form DBSs. These DBSs were subsequently preserved in sealed plastic bags at room temperature. After the extraction of DNA, DBSs were formed, and TaqMan-qPCR was utilized to detect the presence of rAAV vector-derived DNA. The finding confirmed that doping gene-specific fragments were successfully detected in DBSs. This outcome suggests that the DBS method is an effective approach to be considered when developing a comprehensive protocol for gene doping detection.
基因技术的飞速发展引发了人们对可能滥用基因兴奋剂等技术提高运动成绩的担忧。为了识别这种可能性，需要一种可靠的程序来检测兴奋剂基因。虽然兴奋剂基因的检测方法已经问世，但仍有需要进一步改进的地方。其中一个重大挑战是检测样本的储存和运输成本较高。针对这一问题，干血斑（DBS）法不失为一种经济有效的解决方案。本研究旨在评估将 DBS 纳入基因兴奋剂检测流程的实用性。首先从利用 rAAV 载体表达人促红细胞生成素的小鼠身上采集全血样本。然后，将血液置于滤纸中，在室温下晾干五小时，形成 DBSs。这些 DBS 随后被密封在室温下的塑料袋中保存。提取 DNA 后，形成 DBS，并利用 TaqMan-qPCR 检测 rAAV 载体 DNA 的存在。结果证实，在 DBSs 中成功检测到了掺杂基因特异性片段。这一结果表明，在制定全面的基因掺杂检测方案时，DBS 方法是一种值得考虑的有效方法。
{"title":"Detection of Gene Doping Using Dried Blood Spots from a Mouse Model with rAAV9 Vector-Mediated Human Erythropoietin Expression as a Pilot Study","authors":"Norihiro Otani, Yasuharu Kanki, Kieu D. M. Nguyen, T. Sugasawa","doi":"10.3390/analytica5020017","DOIUrl":"https://doi.org/10.3390/analytica5020017","url":null,"abstract":"Rapid advancements in gene technology have raised concerns regarding the potential abuse of techniques, such as gene doping, for enhancing athletic performance. To identify this possibility, a reliable procedure for detecting doping genes is required. Although detection methods for doping genes have been created, there are still areas for further improvement. One significant challenge is the high storage and transport costs of the test samples. For this issue, the dried blood spot (DBS) method can be a cost-effective solution. This study aimed to assess the practicality of incorporating DBSs into the gene doping detection process as a pilot study. Whole-blood samples were initially collected from mice engineered to express human erythropoietin from the rAAV vector. Then, the blood was placed in filter papers and left to dry at room temperature for five hours to form DBSs. These DBSs were subsequently preserved in sealed plastic bags at room temperature. After the extraction of DNA, DBSs were formed, and TaqMan-qPCR was utilized to detect the presence of rAAV vector-derived DNA. The finding confirmed that doping gene-specific fragments were successfully detected in DBSs. This outcome suggests that the DBS method is an effective approach to be considered when developing a comprehensive protocol for gene doping detection.","PeriodicalId":7829,"journal":{"name":"Analytica","volume":"7 2","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-06-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141267632","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 : 2024-06-01DOI: 10.3390/analytica5020016
Sthephane Pereira de Oliveira, Thaís Cristina de Oliveira Cândido, Arnaldo César Pereira, Daniela Nunes da Silva
Catechol (CT) is a phenolic compound widely used in various industrial sectors, but it is toxic; thus, there is a need for methods that aim to identify and quantify the existence of residues of this material in the environment. In this study a disposable printed electrochemical sensor was developed as an effective alternative for determining CT in water samples. The electrode, called SPEC, was manufactured using the screen-printing method using polyethylene terephthalate (PET) as a support, in which a conductive ink based on carbonaceous materials was used to print the working and auxiliary electrodes and a silver/silver chloride of ink on the reference electrode. The optimal ratio for the conductive ink was 6.25% carbon black, 35.42% graphite, and 58.33% nail polish. The ink obtained was characterized by scanning electron microscopy (SEM). The assessment of the effect of pH on the redox process showed Nernstian behavior (0.057 V pH−1), indicating that the process involves the same number of protons and electrons. Under optimized conditions, with 0.2 mol L−1 acetate buffer at pH 5.0, and by square wave voltammetry, the sensor presented sensitivity values of 0.31 μA L μmol−1, a detection limit of 5.96 μmol L−1, and a quantification limit of 19.87 μmol L−1. The sensor was applied to determine CT in tap water samples, and the results showed recoveries between 97.95 and 100.17%.
{"title":"Electrochemical Determination of Catechol Using a Disposable Printed Electrode with Conductive Ink Based on Graphite and Carbon Black","authors":"Sthephane Pereira de Oliveira, Thaís Cristina de Oliveira Cândido, Arnaldo César Pereira, Daniela Nunes da Silva","doi":"10.3390/analytica5020016","DOIUrl":"https://doi.org/10.3390/analytica5020016","url":null,"abstract":"Catechol (CT) is a phenolic compound widely used in various industrial sectors, but it is toxic; thus, there is a need for methods that aim to identify and quantify the existence of residues of this material in the environment. In this study a disposable printed electrochemical sensor was developed as an effective alternative for determining CT in water samples. The electrode, called SPEC, was manufactured using the screen-printing method using polyethylene terephthalate (PET) as a support, in which a conductive ink based on carbonaceous materials was used to print the working and auxiliary electrodes and a silver/silver chloride of ink on the reference electrode. The optimal ratio for the conductive ink was 6.25% carbon black, 35.42% graphite, and 58.33% nail polish. The ink obtained was characterized by scanning electron microscopy (SEM). The assessment of the effect of pH on the redox process showed Nernstian behavior (0.057 V pH−1), indicating that the process involves the same number of protons and electrons. Under optimized conditions, with 0.2 mol L−1 acetate buffer at pH 5.0, and by square wave voltammetry, the sensor presented sensitivity values of 0.31 μA L μmol−1, a detection limit of 5.96 μmol L−1, and a quantification limit of 19.87 μmol L−1. The sensor was applied to determine CT in tap water samples, and the results showed recoveries between 97.95 and 100.17%.","PeriodicalId":7829,"journal":{"name":"Analytica","volume":"66 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141278446","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 : 2024-05-09DOI: 10.3390/analytica5020015
Takashi Hitomi, Hiroyuki Kataoka
Accurate measurement of steroid hormones is crucial to elucidate new mechanisms of action and diagnose steroid metabolism-related diseases. This study presents a simple, sensitive, and automated analytical method for nine representative steroid hormones. The method involves on-line coupling of in-tube solid-phase microextraction (IT-SPME) with liquid chromatography–tandem mass spectrometry (LC–MS/MS). The steroid hormones were extracted and enriched on a Supel-Q PLOT capillary column using IT-SPME. Subsequently, they were separated and detected within 6 min using a Discovery HS F5-3 column and positive ion mode multiple reaction monitoring system via LC–MS/MS. Calibration curves of these compounds using each stable isotope-labeled internal standard (IS) showed linearity with correlation coefficients greater than 0.9990 in the range of 0.01–40 ng/mL, with limits of detection (S/N = 3) of 0.7–21 pg/mL. Moreover, intra- and inter-day variations were lower than 8.1 and 15% (n = 6), respectively. The recoveries of these compounds from saliva samples were in the range of 82–114%. The developed IT-SPME/LC–MS/MS method of steroid hormones is a highly sensitive, specific, and non-invasive analytical method that allows extraction and enrichment with no organic solvents, and enables direct automated online analysis by simply ultrafiltrating a small sample of saliva.
{"title":"Development of Noninvasive Method for the Automated Analysis of Nine Steroid Hormones in Human Saliva by Online Coupling of In-Tube Solid-Phase Microextraction with Liquid Chromatography–Tandem Mass Spectrometry","authors":"Takashi Hitomi, Hiroyuki Kataoka","doi":"10.3390/analytica5020015","DOIUrl":"https://doi.org/10.3390/analytica5020015","url":null,"abstract":"Accurate measurement of steroid hormones is crucial to elucidate new mechanisms of action and diagnose steroid metabolism-related diseases. This study presents a simple, sensitive, and automated analytical method for nine representative steroid hormones. The method involves on-line coupling of in-tube solid-phase microextraction (IT-SPME) with liquid chromatography–tandem mass spectrometry (LC–MS/MS). The steroid hormones were extracted and enriched on a Supel-Q PLOT capillary column using IT-SPME. Subsequently, they were separated and detected within 6 min using a Discovery HS F5-3 column and positive ion mode multiple reaction monitoring system via LC–MS/MS. Calibration curves of these compounds using each stable isotope-labeled internal standard (IS) showed linearity with correlation coefficients greater than 0.9990 in the range of 0.01–40 ng/mL, with limits of detection (S/N = 3) of 0.7–21 pg/mL. Moreover, intra- and inter-day variations were lower than 8.1 and 15% (n = 6), respectively. The recoveries of these compounds from saliva samples were in the range of 82–114%. The developed IT-SPME/LC–MS/MS method of steroid hormones is a highly sensitive, specific, and non-invasive analytical method that allows extraction and enrichment with no organic solvents, and enables direct automated online analysis by simply ultrafiltrating a small sample of saliva.","PeriodicalId":7829,"journal":{"name":"Analytica","volume":" 43","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140995466","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 : 2024-05-08DOI: 10.3390/analytica5020014
Alessandro Zappi, A. Biancolillo, Nicholas Kassouf, Valentina Marassi, Pietro Morozzi, L. Tositti, Dora Melucci
A novel approach for the quantification of recycled polyethylene terephthalate (r-PET) in commercial bottles is presented. Fifty-eight bottle samples from several brands and producers containing different percentages of r-PET were purchased from the market. Samples were analyzed by two spectroscopic methods: near-infrared (NIR) spectroscopy and attenuated total reflection (ATR) spectroscopy in the mid-infrared (MIR) region. No chemical pre-treatment was applied before analyses. The spectra were analyzed by partial-least squares (PLS) regression, and two models for NIR and MIR data were computed. Then, a multi-block regression was applied to join the two datasets. All models were validated by cross-validation and by excluding and projecting onto the model the replicated spectra of one sample at a time. Results demonstrated the potential of this approach, especially considering the variability of commercial samples in terms of additives, shape, or thickness of the bottles: for samples close to the centroids of the models (i.e., from 10 to 50% r-PET), the predictions of multi-block method seldom departed from the expected values of ±10%. Only for samples with 0% declared r-PET, the models showed poor prediction abilities.
{"title":"Quantification of Recycled PET in Commercial Bottles by IR Spectroscopy and Chemometrics","authors":"Alessandro Zappi, A. Biancolillo, Nicholas Kassouf, Valentina Marassi, Pietro Morozzi, L. Tositti, Dora Melucci","doi":"10.3390/analytica5020014","DOIUrl":"https://doi.org/10.3390/analytica5020014","url":null,"abstract":"A novel approach for the quantification of recycled polyethylene terephthalate (r-PET) in commercial bottles is presented. Fifty-eight bottle samples from several brands and producers containing different percentages of r-PET were purchased from the market. Samples were analyzed by two spectroscopic methods: near-infrared (NIR) spectroscopy and attenuated total reflection (ATR) spectroscopy in the mid-infrared (MIR) region. No chemical pre-treatment was applied before analyses. The spectra were analyzed by partial-least squares (PLS) regression, and two models for NIR and MIR data were computed. Then, a multi-block regression was applied to join the two datasets. All models were validated by cross-validation and by excluding and projecting onto the model the replicated spectra of one sample at a time. Results demonstrated the potential of this approach, especially considering the variability of commercial samples in terms of additives, shape, or thickness of the bottles: for samples close to the centroids of the models (i.e., from 10 to 50% r-PET), the predictions of multi-block method seldom departed from the expected values of ±10%. Only for samples with 0% declared r-PET, the models showed poor prediction abilities.","PeriodicalId":7829,"journal":{"name":"Analytica","volume":" 22","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141000015","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 : 2024-05-01DOI: 10.3390/analytica5020013
Rachel de M. Ferreira, B. D. Ribeiro, D. Stapelfeldt, Maria de F. R. Moreira
Aquatic macrophytes like Salvinia sp. have rapid proliferation and a great capacity for ecological adaptation. In addition to these characteristics, this study points to their ability to adsorb contaminants such as dyes, metals, and oils. This work aims, through an adsorption study, to propose an alternative treatment using chemically modified Salvinia sp. (SOH) biomass to remove oil from water. Batch adsorption experiments were performed to observe the effects of concentration, pH, time, temperature, desorption, and reuse of the biomass. The adsorption mechanisms, performance, kinetics, isotherm, thermodynamics, and reusability of biomass were evaluated. Both adsorbents were well-defined by the Freundlich model isotherm. According to the results obtained, the qmax was 898.0 mg g−1 for SOH in oil-in-salt water emulsion in 15 min and 930.59 mg g−1 for Salvinia sp. in natura (SS) in the oil-in-water emulsion. In the fixed-bed column adsorption, the adsorption capacity was 2.99 g g−1 for SS and 3.49 g g−1 for SOH, and the saturation capacity was 42.89 g g−1 SS and 42.99 g g−1 SOH. According to the adsorption models, the Bohart–Adams model best fits the experimental data of this study. The SOH adsorbed oil recovery test was successful, with 100% oil recovery.
像沙维氏藻这样的水生大型藻类具有快速增殖和强大的生态适应能力。除了这些特点外，这项研究还指出了它们吸附染料、金属和油类等污染物的能力。本研究旨在通过吸附研究，提出一种使用化学改性沙维氏藻（SOH）生物质去除水中油类的替代处理方法。批量吸附实验观察了生物质的浓度、pH 值、时间、温度、解吸和再利用的影响。对生物质的吸附机理、性能、动力学、等温线、热力学和可重复使用性进行了评估。这两种吸附剂都有很好的 Freundlich 等温线模型。结果表明，盐包油型水乳液中的 SOH 在 15 分钟内的 qmax 为 898.0 mg g-1，水包油型水乳液中的天然沙维藻（SS）的 qmax 为 930.59 mg g-1。在固定床柱吸附中，SS 的吸附容量为 2.99 g g-1，SOH 为 3.49 g g-1，饱和容量为 42.89 g g-1 SS 和 42.99 g g-1 SOH。根据吸附模型，Bohart-Adams 模型最适合本研究的实验数据。SOH 吸附采油试验获得成功，采油率达到 100%。
{"title":"Treatment of Water Contaminated by Ship Oil: Study of Adsorption in a Fixed-Bed Column","authors":"Rachel de M. Ferreira, B. D. Ribeiro, D. Stapelfeldt, Maria de F. R. Moreira","doi":"10.3390/analytica5020013","DOIUrl":"https://doi.org/10.3390/analytica5020013","url":null,"abstract":"Aquatic macrophytes like Salvinia sp. have rapid proliferation and a great capacity for ecological adaptation. In addition to these characteristics, this study points to their ability to adsorb contaminants such as dyes, metals, and oils. This work aims, through an adsorption study, to propose an alternative treatment using chemically modified Salvinia sp. (SOH) biomass to remove oil from water. Batch adsorption experiments were performed to observe the effects of concentration, pH, time, temperature, desorption, and reuse of the biomass. The adsorption mechanisms, performance, kinetics, isotherm, thermodynamics, and reusability of biomass were evaluated. Both adsorbents were well-defined by the Freundlich model isotherm. According to the results obtained, the qmax was 898.0 mg g−1 for SOH in oil-in-salt water emulsion in 15 min and 930.59 mg g−1 for Salvinia sp. in natura (SS) in the oil-in-water emulsion. In the fixed-bed column adsorption, the adsorption capacity was 2.99 g g−1 for SS and 3.49 g g−1 for SOH, and the saturation capacity was 42.89 g g−1 SS and 42.99 g g−1 SOH. According to the adsorption models, the Bohart–Adams model best fits the experimental data of this study. The SOH adsorbed oil recovery test was successful, with 100% oil recovery.","PeriodicalId":7829,"journal":{"name":"Analytica","volume":"56 7","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141038920","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 : 2024-04-19DOI: 10.3390/analytica5020012
Alessia Iannone, Fabiana Carriera, Cristina Di Fiore, P. Avino
Per- and polyfluoroalkyl substances (PFASs) are carbon–fluorine compounds with widespread industrial and domestic use, posing potential toxicological risks to humans and ecosystems. Several analytical methods have been developed to assess the occurrence of PFASs in the environment, but a standardized method, applicable to all matrices, is still lacking. This paper reviews the extraction and chromatographic detection methods for PFAS assessment in environmental samples, considering parameters such as the LOD, LOQ, and recoveries. Solid phase extraction (SPE) is commonly used, showing high recovery rates for water, soil, and sediment samples using HBL and WAX polymeric sorbents (85–100% and 93–111.5%, respectively). LC-MS has demonstrated low LODs and LOQs in seawater (0.01–0.08 ng L−1; 0.03–0.24 ng L−1), marine sediment (0.002–0.018 ng g−1; 0.004–0.054 ng g−1), and dust (0.08–0.68 pg g−1; 0.26–2.25 pg g−1), indicating its sensitivity when detecting trace PFAS levels. Evaluating PFASs is crucial for the development of future removal strategies and risk assessments. Potential solutions including the use of PFAS substitutes and innovative adsorption techniques for their adsorption could present promise in reducing their environmental presence.
{"title":"Poly- and Perfluoroalkyl Substance (PFAS) Analysis in Environmental Matrices: An Overview of the Extraction and Chromatographic Detection Methods","authors":"Alessia Iannone, Fabiana Carriera, Cristina Di Fiore, P. Avino","doi":"10.3390/analytica5020012","DOIUrl":"https://doi.org/10.3390/analytica5020012","url":null,"abstract":"Per- and polyfluoroalkyl substances (PFASs) are carbon–fluorine compounds with widespread industrial and domestic use, posing potential toxicological risks to humans and ecosystems. Several analytical methods have been developed to assess the occurrence of PFASs in the environment, but a standardized method, applicable to all matrices, is still lacking. This paper reviews the extraction and chromatographic detection methods for PFAS assessment in environmental samples, considering parameters such as the LOD, LOQ, and recoveries. Solid phase extraction (SPE) is commonly used, showing high recovery rates for water, soil, and sediment samples using HBL and WAX polymeric sorbents (85–100% and 93–111.5%, respectively). LC-MS has demonstrated low LODs and LOQs in seawater (0.01–0.08 ng L−1; 0.03–0.24 ng L−1), marine sediment (0.002–0.018 ng g−1; 0.004–0.054 ng g−1), and dust (0.08–0.68 pg g−1; 0.26–2.25 pg g−1), indicating its sensitivity when detecting trace PFAS levels. Evaluating PFASs is crucial for the development of future removal strategies and risk assessments. Potential solutions including the use of PFAS substitutes and innovative adsorption techniques for their adsorption could present promise in reducing their environmental presence.","PeriodicalId":7829,"journal":{"name":"Analytica","volume":" 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140685082","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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