Pub Date : 2023-05-15DOI: 10.30744/brjac.2179-3425.ar-129-2022
P. Mello, G. Bitencourt, T. Berón, Aline Müller
Dietary supplements have been used to overcome nutritional deficiencies and the knowledge concerning essential and non-essential elements is an important issue. In this work the suitability of microwave-induced plasma optical emission spectrometry (MIP OES) for the determination of essential and non-essential elements in dietary supplements was evaluated. Twelve dietary supplement samples of several classifications (vitamins/minerals, minerals, amino acids, and botanicals) were digested in their whole form for determination of essential (Ca, Co, Cu, Fe, K, Mg, Mn, Mo, Na, and Zn) and non-essential (Ag, Al, B, Ba, Be, Cd, Cr, La, Li, Ni, Pb, Sr, and V) elements by MIP OES. Potential non-spectral interferences by common concomitants (C, S, K, Na, and Ca) were evaluated, as well as those by residual acidity of digests. The study of non-spectral interferences showed that a signal suppression effect is observed with higher concentrations of Ca, Na, and K. Relatively good robustness was observed considering the presence of C and S, as well as residual HNO3. The limits of quantification (LOQs) were dependent on the sample mass used for decomposition (from 0.6 to 1.6 g in the commercial product) and on the minimum dilution factor. From the results, there was a prevalence of essential and non-essential elements in vitamins and minerals, minerals, and botanicals-based dietary supplements, whereas lower concentrations were found in the dietary supplements based on amino acids. All elements were in a concentration below the recommended dietary allowances (RDAs), exception for those with the concentration intentionally higher. Accuracy of results by MIP OES was evaluated by using standard reference materials (SRM) NIST 1572 and NIST 1575a. In addition, results showed no statistical difference by comparison with those by ICP OES. MIP OES proved to be a suitable technique for the determination of metals in dietary supplements, being a feasible alternative for the quality control of these products.
{"title":"Determination of Essential and Non-Essential Elements in Dietary Supplements by Microwave-Induced Plasma Optical Emission Spectrometry: Method Development and Study of Non-Spectral Interferences","authors":"P. Mello, G. Bitencourt, T. Berón, Aline Müller","doi":"10.30744/brjac.2179-3425.ar-129-2022","DOIUrl":"https://doi.org/10.30744/brjac.2179-3425.ar-129-2022","url":null,"abstract":"Dietary supplements have been used to overcome nutritional deficiencies and the knowledge concerning essential and non-essential elements is an important issue. In this work the suitability of microwave-induced plasma optical emission spectrometry (MIP OES) for the determination of essential and non-essential elements in dietary supplements was evaluated. Twelve dietary supplement samples of several classifications (vitamins/minerals, minerals, amino acids, and botanicals) were digested in their whole form for determination of essential (Ca, Co, Cu, Fe, K, Mg, Mn, Mo, Na, and Zn) and non-essential (Ag, Al, B, Ba, Be, Cd, Cr, La, Li, Ni, Pb, Sr, and V) elements by MIP OES. Potential non-spectral interferences by common concomitants (C, S, K, Na, and Ca) were evaluated, as well as those by residual acidity of digests. The study of non-spectral interferences showed that a signal suppression effect is observed with higher concentrations of Ca, Na, and K. Relatively good robustness was observed considering the presence of C and S, as well as residual HNO3. The limits of quantification (LOQs) were dependent on the sample mass used for decomposition (from 0.6 to 1.6 g in the commercial product) and on the minimum dilution factor. From the results, there was a prevalence of essential and non-essential elements in vitamins and minerals, minerals, and botanicals-based dietary supplements, whereas lower concentrations were found in the dietary supplements based on amino acids. All elements were in a concentration below the recommended dietary allowances (RDAs), exception for those with the concentration intentionally higher. Accuracy of results by MIP OES was evaluated by using standard reference materials (SRM) NIST 1572 and NIST 1575a. In addition, results showed no statistical difference by comparison with those by ICP OES. MIP OES proved to be a suitable technique for the determination of metals in dietary supplements, being a feasible alternative for the quality control of these products.","PeriodicalId":9115,"journal":{"name":"Brazilian Journal of Analytical Chemistry","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2023-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47297739","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 : 2023-05-15DOI: 10.30744/brjac.2179-3425.rv-07-2023
L. Souza
Global plastic pollution is a serious problem that is increasing over the years since millions of tons of plastics end up in the environment. These plastics are fragmented due to sunlight radiation, biodegradation, and other environmental factors leading to small debris which can be transformed into microplastics and nanoplastics. Due to their small size and high surface area, these materials can be easily absorbed by organisms besides being able to adsorb toxic pollutants. Considering these issues, studies about their toxicity and fate in the environment are of great importance, however, the success of these studies depends on the methods of sampling, sample preparation, and also analysis, which need to be developed and improved. Thus, the current review proposes an integrated approach of methodologies of sampling, sample preparation, and analysis of solid and aqueous samples with microplastics and nanoplastics besides discussing the challenges and new methodologies for microplastics and nanoplastics analysis.
{"title":"The Emerging of Microplastic and Nanoplastic as Pollutants and their Characterization and Analysis","authors":"L. Souza","doi":"10.30744/brjac.2179-3425.rv-07-2023","DOIUrl":"https://doi.org/10.30744/brjac.2179-3425.rv-07-2023","url":null,"abstract":"Global plastic pollution is a serious problem that is increasing over the years since millions of tons of plastics end up in the environment. These plastics are fragmented due to sunlight radiation, biodegradation, and other environmental factors leading to small debris which can be transformed into microplastics and nanoplastics. Due to their small size and high surface area, these materials can be easily absorbed by organisms besides being able to adsorb toxic pollutants. Considering these issues, studies about their toxicity and fate in the environment are of great importance, however, the success of these studies depends on the methods of sampling, sample preparation, and also analysis, which need to be developed and improved. Thus, the current review proposes an integrated approach of methodologies of sampling, sample preparation, and analysis of solid and aqueous samples with microplastics and nanoplastics besides discussing the challenges and new methodologies for microplastics and nanoplastics analysis.","PeriodicalId":9115,"journal":{"name":"Brazilian Journal of Analytical Chemistry","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2023-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41512141","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 : 2023-05-10DOI: 10.30744/brjac.2179-3425.ar-13-2023
Ívero de Sá, C. da Silva, A. R. Nogueira
Two methods were developed for the As and Cr species determination in different kinds of seafood, exploring the LC-ICP-MS potential and chemometric approach to define the extraction conditions. Adequates separation and sensitivity data by LC-ICP-MS were obtained with 0.01 mol L-1 (NH4)2HPO4 in 1% ethanol (pH 8.0) for arsenic, and 0.015 mol L-1 Na2SO4, 0.005 mol L-1 EDTA, and 0.005 mol L-1 NaH2PO4 (pH 7.0) for chromium. The Doehlert matrix and Box-Behnken design defined the ideal extraction conditions for arsenic and chromium species. For As extraction, the optimized conditions employed 0.1 g of sample and 30 mmol L-1 HNO3 at 90°C for 45 min, and Cr, 0.1 g of sample and 0.045 mol L-1 [EDTA] at 90°C for 40 min. Recoveries from 88 to 106% of arsenobetaine (AsB), arsenite [As(III)], dimethylarsinic acid (DMA), monomethylarsonic acid (MMA), arsenate [As(V)], Cr(III) and Cr(VI) were obtained for all evaluated samples. The limits of quantification provided by the proposed methods were 5.3; 52.1; 16.4; 2.8; 83.3; 113.8; 53.9 ng g-1 for AsB, As(III), DMA, MMA, As(V), Cr(III) and Cr(VI) respectively. The trueness was evaluated using certified reference materials and addition and recovery procedures. The sum of the species agreed with the total concentration of arsenic and chromium contents.
{"title":"Chemical Speciation of Arsenic and Chromium in Seafood by LC-ICP-MS","authors":"Ívero de Sá, C. da Silva, A. R. Nogueira","doi":"10.30744/brjac.2179-3425.ar-13-2023","DOIUrl":"https://doi.org/10.30744/brjac.2179-3425.ar-13-2023","url":null,"abstract":"Two methods were developed for the As and Cr species determination in different kinds of seafood, exploring the LC-ICP-MS potential and chemometric approach to define the extraction conditions. Adequates separation and sensitivity data by LC-ICP-MS were obtained with 0.01 mol L-1 (NH4)2HPO4 in 1% ethanol (pH 8.0) for arsenic, and 0.015 mol L-1 Na2SO4, 0.005 mol L-1 EDTA, and 0.005 mol L-1 NaH2PO4 (pH 7.0) for chromium. The Doehlert matrix and Box-Behnken design defined the ideal extraction conditions for arsenic and chromium species. For As extraction, the optimized conditions employed 0.1 g of sample and 30 mmol L-1 HNO3 at 90°C for 45 min, and Cr, 0.1 g of sample and 0.045 mol L-1 [EDTA] at 90°C for 40 min. Recoveries from 88 to 106% of arsenobetaine (AsB), arsenite [As(III)], dimethylarsinic acid (DMA), monomethylarsonic acid (MMA), arsenate [As(V)], Cr(III) and Cr(VI) were obtained for all evaluated samples. The limits of quantification provided by the proposed methods were 5.3; 52.1; 16.4; 2.8; 83.3; 113.8; 53.9 ng g-1 for AsB, As(III), DMA, MMA, As(V), Cr(III) and Cr(VI) respectively. The trueness was evaluated using certified reference materials and addition and recovery procedures. The sum of the species agreed with the total concentration of arsenic and chromium contents.","PeriodicalId":9115,"journal":{"name":"Brazilian Journal of Analytical Chemistry","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2023-05-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46246051","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 : 2023-05-08DOI: 10.30744/brjac.2179-3425.ar-15-2023
Shivarampura Dushyantha, C. Siddaraju, N. Rajendraprasad
Four simple, precise, and cost-effective spectrophotometric methods were designed and validated to assess Dosulepin hydrochloride (DOS) in pure and dosage form. Two of them are direct UV (Methods A and B), and the other two are indirect visible spectrophotometric methods (Methods C and D). Method A is based on the measurement of the chromophoric activity of DOS in 0.1 M acetic acid (AcOH) at 300 nm. Method B involves the measurement of absorbance due to cerium (IV) left in excess after oxidizing DOS at 320 nm. The unreacted cerium (IV) was treated with a large excess of iron (II), which results in iron (III) and cerium (III). The surplus iron (II) forms a red colored complex with o-phenanthroline at a slightly higher pH was measured at 510 nm in Method C. In Method D the iron (III) formed in the redox reaction between unreacted cerium (IV) and iron (II) was made to form a red colour complex with thiocyanate and measured at 480 nm. The methods are applicable over good linear ranges of 1.0-80.0, 0.25-10.0, 0.5-8.0 and 0.50-10.0 µg mL-1 with actual molar absorptivity values of 2.07 × 103, 3.11 × 104, 4.08 × 104 and 3.7 × 104 L mol-1cm-1 for Method A, B, C and D, respectively. The validating parameters like limit of detection (LOD), quantification (LOQ), Sandell sensitivity and others have been reported. The methods proposed were successfully applied to quantify DOS in pharmaceuticals. The Fourier Transform Infrared (FT-IR) spectra of the post degradation DOS were studied, compared with that of pure drug and reached to the possible effect of degradation to stress by stability indicating property of Method A.
设计并验证了四种简单、准确、经济高效的分光光度法来评估纯盐酸多苏列平（DOS）和剂型。其中两种是直接紫外分光光度方法（方法A和B），另两种是间接可见分光光度分析方法（方法C和D）。方法A基于DOS在0.1M乙酸（AcOH）中在300nm处的发色活性的测量。方法B包括测量由于在320nm氧化DOS后剩余过量的铈（IV）引起的吸光度。用大量过量的铁（II）处理未反应的铈（IV），得到铁（III）和铈（III）。剩余的铁（II）在略高的pH下与邻菲罗啉形成红色络合物在方法C中在510nm处测量。在方法D中，使在未反应的铈（IV）和铁（Ⅱ）之间的氧化还原反应中形成的铁（III）与硫氰酸盐形成红色络合物，并在480nm处测量。该方法适用于1.0-80.0、0.25-10.0、0.5-8.0和0.50-10.0µg mL-1的良好线性范围，方法A、B、C和D的实际摩尔吸光系数分别为2.07×103、3.11×104、4.08×104和3.7×104 L mol-1cm-1。已经报道了检测限（LOD）、定量（LOQ）、Sandell灵敏度等验证参数。所提出的方法已成功应用于药品中DOS的定量。研究了降解后DOS的傅立叶变换红外光谱（FT-IR），并与纯药物进行了比较，通过方法A的稳定性指示特性，得出了降解应力的可能效果。
{"title":"Infrared and Electronic Spectroscopy for Assay of Dosulepin in Pharmaceuticals: Stability Indicating Study and Quantification Approach","authors":"Shivarampura Dushyantha, C. Siddaraju, N. Rajendraprasad","doi":"10.30744/brjac.2179-3425.ar-15-2023","DOIUrl":"https://doi.org/10.30744/brjac.2179-3425.ar-15-2023","url":null,"abstract":"Four simple, precise, and cost-effective spectrophotometric methods were designed and validated to assess Dosulepin hydrochloride (DOS) in pure and dosage form. Two of them are direct UV (Methods A and B), and the other two are indirect visible spectrophotometric methods (Methods C and D). Method A is based on the measurement of the chromophoric activity of DOS in 0.1 M acetic acid (AcOH) at 300 nm. Method B involves the measurement of absorbance due to cerium (IV) left in excess after oxidizing DOS at 320 nm. The unreacted cerium (IV) was treated with a large excess of iron (II), which results in iron (III) and cerium (III). The surplus iron (II) forms a red colored complex with o-phenanthroline at a slightly higher pH was measured at 510 nm in Method C. In Method D the iron (III) formed in the redox reaction between unreacted cerium (IV) and iron (II) was made to form a red colour complex with thiocyanate and measured at 480 nm. The methods are applicable over good linear ranges of 1.0-80.0, 0.25-10.0, 0.5-8.0 and 0.50-10.0 µg mL-1 with actual molar absorptivity values of 2.07 × 103, 3.11 × 104, 4.08 × 104 and 3.7 × 104 L mol-1cm-1 for Method A, B, C and D, respectively. The validating parameters like limit of detection (LOD), quantification (LOQ), Sandell sensitivity and others have been reported. The methods proposed were successfully applied to quantify DOS in pharmaceuticals. The Fourier Transform Infrared (FT-IR) spectra of the post degradation DOS were studied, compared with that of pure drug and reached to the possible effect of degradation to stress by stability indicating property of Method A.","PeriodicalId":9115,"journal":{"name":"Brazilian Journal of Analytical Chemistry","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2023-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44335621","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 : 2023-04-11DOI: 10.30744/brjac.2179-3425.rv-126-2022
In recent decades, green analytical chemistry has received more attention due to the growing concern over environmental conservation and the use of non-renewable resources. Among the analytical techniques, liquid chromatography is the most widely used in quality control analysis of food, drugs, and clinical analysis among others, but it is also the technique that uses the largest amount of hazardous organic solvents and generates large volumes of waste. Therefore, strategies such as the miniaturization of chromatographic systems, the use of online sample preparation systems, and the replacement of hazardous organic solvents by green solvents have been applied to develop greener chromatographic methods. In this paper, strategies for greening methods and recent developments in green chromatography are presented. In addition, metrics for the proper evaluation of these methods are discussed.
{"title":"Recent Developments in Green Chromatography","authors":"","doi":"10.30744/brjac.2179-3425.rv-126-2022","DOIUrl":"https://doi.org/10.30744/brjac.2179-3425.rv-126-2022","url":null,"abstract":"In recent decades, green analytical chemistry has received more attention due to the growing concern over environmental conservation and the use of non-renewable resources. Among the analytical techniques, liquid chromatography is the most widely used in quality control analysis of food, drugs, and clinical analysis among others, but it is also the technique that uses the largest amount of hazardous organic solvents and generates large volumes of waste. Therefore, strategies such as the miniaturization of chromatographic systems, the use of online sample preparation systems, and the replacement of hazardous organic solvents by green solvents have been applied to develop greener chromatographic methods. In this paper, strategies for greening methods and recent developments in green chromatography are presented. In addition, metrics for the proper evaluation of these methods are discussed.","PeriodicalId":9115,"journal":{"name":"Brazilian Journal of Analytical Chemistry","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2023-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45230735","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 : 2023-04-04DOI: 10.30744/brjac.2179-3425.editorial.pvoliveira.n39
P. Oliveira
Analytical Chemistry has been consolidating itself over the years as a multidisciplinary area that has strong influence in the main branches of science. From the point of view of methods proposition, there are many unanswered questions that cannot do without analytical support. One of the great challenges is to meet some of the demands associated with sustainable development goals. The 17 sustainable development goals (SDGs) adopted by the United Nations Development Program since 2015 are “a universal call to action to end poverty, protect the planet, and ensure that by 2030 all people enjoy peace and prosperity”. The goals are ambitious and must balance social, economic, and environmental sustainability. Among the range of issues and challenges are the quality control of food, emerging microplastics pollution, nanoparticle and single particle determination, the control and removal of toxic elements and substances from environmental systems (water, soil, and air), and all chemical hazards that societies are exposed to today, which need attention and control. A quick observation of the 17 SDGs makes it possible to see how analytical chemistry can play an important role in fulfilling these challenging tasks. Over the years, analytical chemistry has evolved in such a way that the associated analytical techniques and methods are conducted quickly, safely, and with metrological quality. The creativity, knowhow, technology, and financial resources from all of society are necessary to achieve the SDGs in every context. This first volume of the 2023 BrJAC brings reflections and contributions that show adherence to some challenges mentioned above. The point of view of volatile species generation (VSG) for trace element and speciation analysis, including hydrides and different chemical structures, forming volatile species, such as carbonyls, alkyl-halides, and free atoms, nanoparticles, chelates, and oxides is a demonstration. The contribution on the preparation and use of miniaturized and low-cost electrochemical sensors shows the strength of this area, especially in the group of Brazilian scientists, and will undoubtedly contribute significantly to the identification of groups or different species or molecules. The review section shows the state of the art of capillary electrophoresis (CE) applied to human urine analysis for clinical diagnosis. The articles section covers auto-machine learning algorithms applied to vibrational spectroscopy data for the quality control of biodiesel; the determination of monomers of ethyl acrylate in commercial latex resin; spectrophotometric methods for the quality control of sodium diclofenac in tablets and lead-complex in vegetables using a new reagent for determination; and finally, a forensic contribution reporting a case of cocaine trafficking in asphaltic material. Enjoy and make good reading of the current issue!
{"title":"Sustainable Development Goals and Analytical Chemistry","authors":"P. Oliveira","doi":"10.30744/brjac.2179-3425.editorial.pvoliveira.n39","DOIUrl":"https://doi.org/10.30744/brjac.2179-3425.editorial.pvoliveira.n39","url":null,"abstract":"Analytical Chemistry has been consolidating itself over the years as a multidisciplinary area that has strong influence in the main branches of science. From the point of view of methods proposition, there are many unanswered questions that cannot do without analytical support. One of the great challenges is to meet some of the demands associated with sustainable development goals. The 17 sustainable development goals (SDGs) adopted by the United Nations Development Program since 2015 are “a universal call to action to end poverty, protect the planet, and ensure that by 2030 all people enjoy peace and prosperity”. The goals are ambitious and must balance social, economic, and environmental sustainability. Among the range of issues and challenges are the quality control of food, emerging microplastics pollution, nanoparticle and single particle determination, the control and removal of toxic elements and substances from environmental systems (water, soil, and air), and all chemical hazards that societies are exposed to today, which need attention and control. A quick observation of the 17 SDGs makes it possible to see how analytical chemistry can play an important role in fulfilling these challenging tasks. Over the years, analytical chemistry has evolved in such a way that the associated analytical techniques and methods are conducted quickly, safely, and with metrological quality. The creativity, knowhow, technology, and financial resources from all of society are necessary to achieve the SDGs in every context. This first volume of the 2023 BrJAC brings reflections and contributions that show adherence to some challenges mentioned above. The point of view of volatile species generation (VSG) for trace element and speciation analysis, including hydrides and different chemical structures, forming volatile species, such as carbonyls, alkyl-halides, and free atoms, nanoparticles, chelates, and oxides is a demonstration. The contribution on the preparation and use of miniaturized and low-cost electrochemical sensors shows the strength of this area, especially in the group of Brazilian scientists, and will undoubtedly contribute significantly to the identification of groups or different species or molecules. The review section shows the state of the art of capillary electrophoresis (CE) applied to human urine analysis for clinical diagnosis. The articles section covers auto-machine learning algorithms applied to vibrational spectroscopy data for the quality control of biodiesel; the determination of monomers of ethyl acrylate in commercial latex resin; spectrophotometric methods for the quality control of sodium diclofenac in tablets and lead-complex in vegetables using a new reagent for determination; and finally, a forensic contribution reporting a case of cocaine trafficking in asphaltic material. Enjoy and make good reading of the current issue!","PeriodicalId":9115,"journal":{"name":"Brazilian Journal of Analytical Chemistry","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2023-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48925814","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 : 2023-04-04DOI: 10.30744/brjac.2179-3425.point-of-view-jkratzer.n39
J. Kratzer
The current concept of trace element analysis relies mainly on liquid nebulization to atomic spectrometric detectors characterized by a low sample introduction efficiency, typically reaching 5–8%. This is the bottleneck of all the common nebulizers regardless of the detector employed. As a consequence, more efficient approaches to analyte introduction into element-specific detectors, including atomic absorption (AAS), atomic fluorescence (AFS) and inductively coupled plasma (ICP) with either optical emission (OES) or mass spectrometry (MS) detection, have been sought. One of the strategies is volatile species generation (VSG) – a group of techniques based on analyte derivatization in order to form a volatile compound prior to spectrometric detection.1 Selective analyte conversion from liquid to gas phase results not only in enhanced analyte introduction efficiency but also in separation of the analyte from the sample matrix, leading to a reduced risk of interference.1 Additionally, VSG can employ substantially higher sample introduction flow rates than nebulization, further improving the resulting detection power. In principle, conversion of an analyte to the corresponding volatile compound can be achieved in three ways: chemically (C-VSG),1,2 electrochemically (Ec-VSG)3 or photochemically (P-VSG).4 Presently, hydride generation (HG) is the dominant and most explored VSG technique. However, HG is restricted to hydride-forming elements only, including thus ca eight analytes such as As, Se, Sb, Bi, Pb, Sn, Ge and Te.1 C-VSG, i.e. chemical reduction by means of NaBH4, is the most common approach to HG. Under the optimized conditions, the efficiency of chemical hydride generation (C-HG) reaches 100%, making this approach attractive for routine measurements. Owing to the benefits of the HG technique, effort has been made to expand the number of elements detectable by means of VSG to include volatile compounds other than binary hydrides. Generation of cold mercury vapors,1 i.e. free Hg atoms, is another example of a routinely used VSG technique, the popularity of which is comparable to that of HG. VSG-based approaches have been intensively explored in the last 15–20 years in order to make use of the benefits offered by VSG for elements other than hydride-forming elements and mercury. C-VSG and P-VSG have been employed as the most dominant strategies.2 Presently, successful VSG of more than 40 elements including transition and noble metals and even non-metals (S, P, Si, F, Cl, Br, I) has been reported.2 The volatile species generated are of different chemical structures including, e.g., carbonyls (Fe, Co, Ni, Mo, W), alkyl-halides (Cl, Br, I), free atoms (Cd), nanoparticles (Ag, Au, Cu, Pd), chelates (Pd) and oxides (Os). The recent challenges in the field of total element content determination at ultratrace levels by means of VSG lie in: 1) extending the VSG technique to new elements; 2) identifying the structure of the volatile species generated; 3) u
{"title":"Volatile Species Generation for Trace Element and Speciation Analysis – Current State and Future Perspectives","authors":"J. Kratzer","doi":"10.30744/brjac.2179-3425.point-of-view-jkratzer.n39","DOIUrl":"https://doi.org/10.30744/brjac.2179-3425.point-of-view-jkratzer.n39","url":null,"abstract":"The current concept of trace element analysis relies mainly on liquid nebulization to atomic spectrometric detectors characterized by a low sample introduction efficiency, typically reaching 5–8%. This is the bottleneck of all the common nebulizers regardless of the detector employed. As a consequence, more efficient approaches to analyte introduction into element-specific detectors, including atomic absorption (AAS), atomic fluorescence (AFS) and inductively coupled plasma (ICP) with either optical emission (OES) or mass spectrometry (MS) detection, have been sought. One of the strategies is volatile species generation (VSG) – a group of techniques based on analyte derivatization in order to form a volatile compound prior to spectrometric detection.1 Selective analyte conversion from liquid to gas phase results not only in enhanced analyte introduction efficiency but also in separation of the analyte from the sample matrix, leading to a reduced risk of interference.1 Additionally, VSG can employ substantially higher sample introduction flow rates than nebulization, further improving the resulting detection power. In principle, conversion of an analyte to the corresponding volatile compound can be achieved in three ways: chemically (C-VSG),1,2 electrochemically (Ec-VSG)3 or photochemically (P-VSG).4 Presently, hydride generation (HG) is the dominant and most explored VSG technique. However, HG is restricted to hydride-forming elements only, including thus ca eight analytes such as As, Se, Sb, Bi, Pb, Sn, Ge and Te.1 C-VSG, i.e. chemical reduction by means of NaBH4, is the most common approach to HG. Under the optimized conditions, the efficiency of chemical hydride generation (C-HG) reaches 100%, making this approach attractive for routine measurements. Owing to the benefits of the HG technique, effort has been made to expand the number of elements detectable by means of VSG to include volatile compounds other than binary hydrides. Generation of cold mercury vapors,1 i.e. free Hg atoms, is another example of a routinely used VSG technique, the popularity of which is comparable to that of HG. VSG-based approaches have been intensively explored in the last 15–20 years in order to make use of the benefits offered by VSG for elements other than hydride-forming elements and mercury. C-VSG and P-VSG have been employed as the most dominant strategies.2 Presently, successful VSG of more than 40 elements including transition and noble metals and even non-metals (S, P, Si, F, Cl, Br, I) has been reported.2 The volatile species generated are of different chemical structures including, e.g., carbonyls (Fe, Co, Ni, Mo, W), alkyl-halides (Cl, Br, I), free atoms (Cd), nanoparticles (Ag, Au, Cu, Pd), chelates (Pd) and oxides (Os). The recent challenges in the field of total element content determination at ultratrace levels by means of VSG lie in: 1) extending the VSG technique to new elements; 2) identifying the structure of the volatile species generated; 3) u","PeriodicalId":9115,"journal":{"name":"Brazilian Journal of Analytical Chemistry","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2023-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47955556","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 : 2023-04-04DOI: 10.30744/brjac.2179-3425.interview.ivo.raimundo
Ivo Raimundo Jr
Ivo M. Raimundo Jr. holds a degree in chemistry (1983), a master’s degree in chemistry (1989), and a doctorate in analytical chemistry (1995), all from the Institute of Chemistry, University of Campinas (IQ-Unicamp), Brazil. He carried out postdoctoral studies at the University of Manchester Institute of Science and Technology (UMIST), Manchester, England (1997/98), and the University of South Carolina, Columbia, USA (2017). He is currently Associate Professor at the Department of Analytical Chemistry at IQ - Unicamp. He was Associate Director (2006–2009) and Director (2009–2015) of the Pluridisciplinary Center for Chemical, Biological and Agricultural Research (CPQBA) at Unicamp, Secretary of the Brazilian Chemical Society, Campinas Regional (2020-2022) and is currently its treasurer. He has served as an Associate Editor of the Journal of the Brazilian Chemical Society since 2019. Prof. Raimundo Jr has experience in instrumentation and automation in analytical chemistry, working mainly in the following areas: optical (nano)sensors, microfabrication of analytical systems, and laser-induced breakdown spectroscopy (LIBS).
Ivo M.Raimundo Jr.拥有化学学位（1983年）、化学硕士学位（1989年）和分析化学博士学位（1995年），均来自巴西坎皮纳斯大学化学研究所。他曾在英国曼彻斯特大学科技学院（UMIST）（1997/98）和美国哥伦比亚南卡罗来纳大学（2017）进行博士后研究。他目前是IQ-Unicamp分析化学系的副教授。他曾任联合国大学化学、生物和农业研究多学科中心（CPQBA）副主任（2006-2009年）和主任（2009-2015年），坎皮纳斯地区巴西化学学会秘书（2020-2022年），现任财务主管。自2019年以来，他一直担任《巴西化学学会杂志》副主编。Raimundo Jr教授在分析化学的仪器和自动化方面拥有丰富的经验，主要从事以下领域的工作：光学（纳米）传感器、分析系统的微制造和激光诱导击穿光谱（LIBS）。
{"title":"Professor Ivo M. Raimundo Jr., a researcher concerned about the current state of science in Brazil, kindly granted BrJAC an interview","authors":"Ivo Raimundo Jr","doi":"10.30744/brjac.2179-3425.interview.ivo.raimundo","DOIUrl":"https://doi.org/10.30744/brjac.2179-3425.interview.ivo.raimundo","url":null,"abstract":"Ivo M. Raimundo Jr. holds a degree in chemistry (1983), a master’s degree in chemistry (1989), and a doctorate in analytical chemistry (1995), all from the Institute of Chemistry, University of Campinas (IQ-Unicamp), Brazil. He carried out postdoctoral studies at the University of Manchester Institute of Science and Technology (UMIST), Manchester, England (1997/98), and the University of South Carolina, Columbia, USA (2017). He is currently Associate Professor at the Department of Analytical Chemistry at IQ - Unicamp. He was Associate Director (2006–2009) and Director (2009–2015) of the Pluridisciplinary Center for Chemical, Biological and Agricultural Research (CPQBA) at Unicamp, Secretary of the Brazilian Chemical Society, Campinas Regional (2020-2022) and is currently its treasurer. He has served as an Associate Editor of the Journal of the Brazilian Chemical Society since 2019. Prof. Raimundo Jr has experience in instrumentation and automation in analytical chemistry, working mainly in the following areas: optical (nano)sensors, microfabrication of analytical systems, and laser-induced breakdown spectroscopy (LIBS).","PeriodicalId":9115,"journal":{"name":"Brazilian Journal of Analytical Chemistry","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2023-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49317811","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 : 2023-04-04DOI: 10.30744/brjac.2179-3425.letter-bcjanegitz.n39
B. Janegitz
Since the decade of the 90s when the first works of professor Joseph Wang were published, screen-printed electrodes have been proposed for many objectives. In the first works in Brazil a few years later, some authors proposed electrochemical sensors using graphite from batteries, which provide great results for the determination of several analytes.1 In another interesting work, Professor Lucio Angnes (USP) and collaborators prepared gold electrodes from CD, which presented a thin film of the noble metal.2 They obtained an extremely low-cost electrochemical sensor. After that, this research line gained notoriety in Brazil, and the number of groups and papers has increased considerably. In this regard, we can highlight some researchers that have been working on low-cost and disposable electrochemical sensors, including Lauro Kubota (UNICAMP), Luiz Humberto Marcolino Junior (UFPR), Márcio Fernando Bergamini (UFPR), Ronaldo Censi Faria (UFSCar), Éder Cavalheiro (USP), Osvaldo Novais de Oliveira Junior (USP), Sergio Spínola (USP), Murilo Santiago (CNPEM), Renato Souza Lima (CNPEM), Orlando Fatibello Filho (UFSCar), Wendell Coltro (USP), William Reis (UNICAMP), and Thiago Paixão (USP). The laboratory of Sensors, Nanomedicine, and Nanostructured Materials (LSNano) located at UFSCar Araras has also developed low-cost sensors using recyclable materials and conductive inks with simple preparation. Low-cost electrodes can be prepared with infinite possibilities by using different substrates, such as circuit boards,3 acetate sheets,4 and polyethylene terephthalate (PET) from bottles5 as well as paper6. In the last example, various types of papers have been applied in this area, including cardboard,7 waterproof,6 and adhesives8. Therefore, materials that we use daily can become important devices with great applications. There are many options to produce low-cost electrochemical sensors, including pencil drawing, stencil, laser scribing, and screen-printing techniques.9 The strategy depends on the subject and the materials that have been deposited to be used as conductors. In this context, the screen-printing technique is come from the t-shirt preparation and is an excellent alternative to produce hundreds of sensors in a few minutes. They can be applied by using different electrochemical techniques, such as potentiometry, voltammetry, and electrochemical impedance spectroscopy. For this purpose, low-cost inks, which are made of a polymer and a conductive material, are necessary. Conductive inks can be prepared with water based-polymers,10 nail polish,11 and traditional polymers based on organic solvents12. Otherwise, graphite carbon nanotubes and/or graphene and carbon dots have been used as conductive carbon-based materials.13 Also, metallic nanoparticles such as copper, platinum, and gold can be great alternatives for this intention but can be quite costly.
{"title":"Preparation and Use of Low-Cost Electrochemical Sensors","authors":"B. Janegitz","doi":"10.30744/brjac.2179-3425.letter-bcjanegitz.n39","DOIUrl":"https://doi.org/10.30744/brjac.2179-3425.letter-bcjanegitz.n39","url":null,"abstract":"Since the decade of the 90s when the first works of professor Joseph Wang were published, screen-printed electrodes have been proposed for many objectives. In the first works in Brazil a few years later, some authors proposed electrochemical sensors using graphite from batteries, which provide great results for the determination of several analytes.1 In another interesting work, Professor Lucio Angnes (USP) and collaborators prepared gold electrodes from CD, which presented a thin film of the noble metal.2 They obtained an extremely low-cost electrochemical sensor. After that, this research line gained notoriety in Brazil, and the number of groups and papers has increased considerably. In this regard, we can highlight some researchers that have been working on low-cost and disposable electrochemical sensors, including Lauro Kubota (UNICAMP), Luiz Humberto Marcolino Junior (UFPR), Márcio Fernando Bergamini (UFPR), Ronaldo Censi Faria (UFSCar), Éder Cavalheiro (USP), Osvaldo Novais de Oliveira Junior (USP), Sergio Spínola (USP), Murilo Santiago (CNPEM), Renato Souza Lima (CNPEM), Orlando Fatibello Filho (UFSCar), Wendell Coltro (USP), William Reis (UNICAMP), and Thiago Paixão (USP). The laboratory of Sensors, Nanomedicine, and Nanostructured Materials (LSNano) located at UFSCar Araras has also developed low-cost sensors using recyclable materials and conductive inks with simple preparation. Low-cost electrodes can be prepared with infinite possibilities by using different substrates, such as circuit boards,3 acetate sheets,4 and polyethylene terephthalate (PET) from bottles5 as well as paper6. In the last example, various types of papers have been applied in this area, including cardboard,7 waterproof,6 and adhesives8. Therefore, materials that we use daily can become important devices with great applications. There are many options to produce low-cost electrochemical sensors, including pencil drawing, stencil, laser scribing, and screen-printing techniques.9 The strategy depends on the subject and the materials that have been deposited to be used as conductors. In this context, the screen-printing technique is come from the t-shirt preparation and is an excellent alternative to produce hundreds of sensors in a few minutes. They can be applied by using different electrochemical techniques, such as potentiometry, voltammetry, and electrochemical impedance spectroscopy. For this purpose, low-cost inks, which are made of a polymer and a conductive material, are necessary. Conductive inks can be prepared with water based-polymers,10 nail polish,11 and traditional polymers based on organic solvents12. Otherwise, graphite carbon nanotubes and/or graphene and carbon dots have been used as conductive carbon-based materials.13 Also, metallic nanoparticles such as copper, platinum, and gold can be great alternatives for this intention but can be quite costly.","PeriodicalId":9115,"journal":{"name":"Brazilian Journal of Analytical Chemistry","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2023-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49334834","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 : 2023-04-03DOI: 10.30744/brjac.2179-3425.ar-93-2022
F. Felix, Matheus Bazzana, L. Assis, Bethânia Mansur, Sara S. Vieira, Z. Magriotis, Leonardo Kumura, A. Saczk
An electrochemical sensor modified with zeolite dealuminated with citric acid was developed for the determination of hydroxyzine in pharmaceutical products during BIA-amperometry experiments. The modified electrochemical sensor was prepared by mixing powdered graphite with zeolite treated with citric acid homogenized with hexane and mineral oil (60:20:20% w/w/w respectively). The developed sensor showed reproducible amperometric responses in a linear range of 1.0x10-6 – 2.0x10-5 mol L-1 in +1,28V (vs. Ag/AgCl). The detection limit and detection limit found were 3.10x10-7 mol L-1 e 1.04x10-6 mol L-1, respectively. The method developed by BIA-amperometry was applied for the determination of the analyte in tablets and commercial syrups and the results found agreement with the nominal values of the commercial samples.
{"title":"Development of an electrochemical sensor modified with dealuminated zeolite with citric acid for hydroxyzine determination by BIA-Amperometry","authors":"F. Felix, Matheus Bazzana, L. Assis, Bethânia Mansur, Sara S. Vieira, Z. Magriotis, Leonardo Kumura, A. Saczk","doi":"10.30744/brjac.2179-3425.ar-93-2022","DOIUrl":"https://doi.org/10.30744/brjac.2179-3425.ar-93-2022","url":null,"abstract":"An electrochemical sensor modified with zeolite dealuminated with citric acid was developed for the determination of hydroxyzine in pharmaceutical products during BIA-amperometry experiments. The modified electrochemical sensor was prepared by mixing powdered graphite with zeolite treated with citric acid homogenized with hexane and mineral oil (60:20:20% w/w/w respectively). The developed sensor showed reproducible amperometric responses in a linear range of 1.0x10-6 – 2.0x10-5 mol L-1 in +1,28V (vs. Ag/AgCl). The detection limit and detection limit found were 3.10x10-7 mol L-1 e 1.04x10-6 mol L-1, respectively. The method developed by BIA-amperometry was applied for the determination of the analyte in tablets and commercial syrups and the results found agreement with the nominal values of the commercial samples.","PeriodicalId":9115,"journal":{"name":"Brazilian Journal of Analytical Chemistry","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2023-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44340837","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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