Quimica Nova最新文献_第3页

RAPID METHOD FOR SIMULTANEOUS DETERMINATION OF CIS-9, TRANS-11 AND TRANS-10, CIS-12 CONJUGATED LINOLEIC ACID ISOMERS IN MILK BY GC-FID gc-fid快速同时测定牛奶中顺式-9、反式-11和反式-10、顺式-12共轭亚油酸异构体

IF 0.8 4区化学

Quimica Nova Pub Date : 2023-08-28 DOI: 10.21577/0100-4042.20230026

B. Porto, I. Faria, Jéssica Cordeiro Queiroz de Souza, Olívia Moreira, M. D. da Gama, M. D. de Oliveira

{"title":"RAPID METHOD FOR SIMULTANEOUS DETERMINATION OF CIS-9, TRANS-11 AND TRANS-10, CIS-12 CONJUGATED LINOLEIC ACID ISOMERS IN MILK BY GC-FID","authors":"B. Porto, I. Faria, Jéssica Cordeiro Queiroz de Souza, Olívia Moreira, M. D. da Gama, M. D. de Oliveira","doi":"10.21577/0100-4042.20230026","DOIUrl":"https://doi.org/10.21577/0100-4042.20230026","url":null,"abstract":"Ruminant milk is the lead source of conjugated linoleic acid (CLA) in the human diet, with cis-9, trans-11 CLA being the major among all. Small amounts of trans-10, cis-12 CLA are also found in synthetic supplements. Since both isomers are biologically active with potential health benefits, there is great interest in quantifying them for quality control routines. An alternative method for the analysis of the aforementioned CLAs by fast gas chromatography (GC) is discussed in the present study. The fatty acid methyl ester mixture obtained by alkaline catalysis was injected into a GC equipped with a flame ionization detector (FID) and fitted with an ionic liquid SLB-IL111 chromatographic column (15 m × 0.10 mm × 0.08 µm). Separation was achieved in less than 5 min using a 168 °C isotherm run. Both CLA isomers were quantified by using of single point standard addition statistical approach. Results were contested to those obtained using the recommended 100 m long CP-Sil88 capillary column and none evidence of significant differences was found within 95% confidence interval. Therefore, the proposed method could be valuable to focused regulatory routines of large numbers of samples with greater analytical frequency.","PeriodicalId":49641,"journal":{"name":"Quimica Nova","volume":"1 1","pages":""},"PeriodicalIF":0.8,"publicationDate":"2023-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68271158","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

GESTÃO DE RESÍDUOS NOS LABORATÓRIOS DA UNIVERSIDADE DE ÉVORA (2007-2021) evora大学实验室的废物管理(2007-2021)

IF 0.8 4区化学

Quimica Nova Pub Date : 2023-08-28 DOI: 10.21577/0100-4042.20230042

{"title":"GESTÃO DE RESÍDUOS NOS LABORATÓRIOS DA UNIVERSIDADE DE ÉVORA (2007-2021)","authors":"","doi":"10.21577/0100-4042.20230042","DOIUrl":"https://doi.org/10.21577/0100-4042.20230042","url":null,"abstract":"WASTE MANAGEMENT IN THE LABORATORIES OF THE UNIVERSITY OF ÉVORA (2007-2021). Waste generated in university laboratories is an important component of university waste management, especially regarding their hazardousness and, also, the cost involved in their forwarding. To make a good management of this waste, it is essential to know the amount generated and the composition. However, this type of information remains scarce. In this work, waste from the laboratories of the University of Évora (Portugal) was surveyed from 2007 to 2021, using existing records. In the 15 years under analysis, the laboratories of the University of Évora generated about 61 tonnes of waste, 88% of which were hazardous and 66% were in the liquid state. In addition, only 3% of this waste was subjected to recovery operations. Moreover, the COVID-19 pandemic contributed to a double increase in hospital waste generated and to a substantially decreased of hazardous liquid waste from the laboratory activity, especially in the first year of the pandemic. In 2021, the second year of the pandemic, there was a “return to normality”, reaching the highest value of waste generated in the laboratories, of 8.6 tonnes. Finally, possible solutions for improving laboratory waste management were also discussed.","PeriodicalId":49641,"journal":{"name":"Quimica Nova","volume":"1 1","pages":""},"PeriodicalIF":0.8,"publicationDate":"2023-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68271577","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

BISMUTH-ANTIMONY FILM ELECTRODE FOR STRIPPING VOLTAMMETRIC DETERMINATION OF TRACE CADMIUM AND LEAD IN THAI RICE WINE 铋锑膜电极溶出伏安法测定泰国米酒中痕量镉和铅

IF 0.8 4区化学

Quimica Nova Pub Date : 2023-08-28 DOI: 10.21577/0100-4042.20230043

Watsaka Siriangkhawut, Kraingkrai Ponhong, P. Chantiratikul, Parita Mayotha

{"title":"BISMUTH-ANTIMONY FILM ELECTRODE FOR STRIPPING VOLTAMMETRIC DETERMINATION OF TRACE CADMIUM AND LEAD IN THAI RICE WINE","authors":"Watsaka Siriangkhawut, Kraingkrai Ponhong, P. Chantiratikul, Parita Mayotha","doi":"10.21577/0100-4042.20230043","DOIUrl":"https://doi.org/10.21577/0100-4042.20230043","url":null,"abstract":"Stripping analysis was proposed for the voltammetric determination of trace cadmium and lead in local rice wine alcoholic beverages. A bismuth-antimony film electrode (Bi-SbFE) was employed for accumulative preconcentration of trace metals by adding 4 mg L-1 of bismuth and 1 mg L-1 of antimony directly to the sample solution and simultaneously depositing bismuth, antimony, and trace cadmium and lead target metals on the glassy carbon electrode by applying a fixed potential of –1.1 V versus the Ag/AgCl reference electrode for 300 s. Pre-treatment parameters for mineralization of the sample were optimized using the wet acid digestion procedure. Under the optimum conditions, linear calibration graphs ranging 20-200 µg L-1 for Cd and Pb were obtained with detection limits of 0.22 and 0.62 µg L-1 and limits of quantitation 0.73 and 2.07 µg L-1, respectively. Reproducibility values for seven replicate analyses of 50 µg L-1 Cd and Pb were 3.6 and 3.3%, respectively. The developed method was successful for Cd and Pb analyses in Thai rice wine samples and results were validated by the flame atomic absorption spectrometric method. Most samples were not contaminated with Cd and Pb. The amount of Cd contaminants in only one of rice wine sample was still lower than the maximum permitted level of Cd in wine.","PeriodicalId":49641,"journal":{"name":"Quimica Nova","volume":"1 1","pages":""},"PeriodicalIF":0.8,"publicationDate":"2023-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68271745","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

PRINCIPAL COMPONENT ANALYSIS (PCA) PARA A AVALIAÇÃO DE DADOS QUÍMICOS E GERAÇÃO DE HEAT MAPS: UM TUTORIAL 主成分分析(pca) para a avaliaÇÃo de dados quÍmicos e geraÇÃo de热图:um教程

IF 0.8 4区化学

Quimica Nova Pub Date : 2023-08-28 DOI: 10.21577/0100-4042.20230030

Dennis Ferreira, Leticia Rodrigues, Fabiola Pereira, Edenir Pereira‑Filho

引用次数: 0

TRANSIÇÕES ELETRÔNICAS EM α-Fe2O3: MODELOS TEÓRICOS E LIMITAÇÕES α-Fe2O3中的电子跃迁:理论模型和局限性

IF 0.8 4区化学

Quimica Nova Pub Date : 2023-08-28 DOI: 10.21577/0100-4042.20230036

Isabela Santos, Dalva de Faria

引用次数: 0

EFEITOS DAS MÚLTIPLAS ESTRUTURAS E DA ANARMONICIDADE TORCIONAL PARA AS REAÇÕES DE ABSTRAÇÃO DE HIDROGÊNIO NO BUTANOATO DE METILA PELO RADICAL H 多结构和扭转非和谐对丁酸甲酯中氢自由基萃取反应的影响

IF 0.8 4区化学

Quimica Nova Pub Date : 2023-08-28 DOI: 10.21577/0100-4042.20230040

J. Nascimento, Tiago Alves

引用次数: 0

UMA TRADUÇÃO COMENTADA DO ARTIGO “ÁCIDOS E BASES” DE GILBERT NEWTON LEWIS 吉尔伯特·牛顿·刘易斯的文章《酸与碱》的评论翻译

IF 0.8 4区化学

Quimica Nova Pub Date : 2023-08-28 DOI: 10.21577/0100-4042.20230035

Regiane dos Santos, Wellington Pereira De Queirós, F. Damasceno, L. Batista

{"title":"UMA TRADUÇÃO COMENTADA DO ARTIGO “ÁCIDOS E BASES” DE GILBERT NEWTON LEWIS","authors":"Regiane dos Santos, Wellington Pereira De Queirós, F. Damasceno, L. Batista","doi":"10.21577/0100-4042.20230035","DOIUrl":"https://doi.org/10.21577/0100-4042.20230035","url":null,"abstract":"A COMMENTED TRANSLATION OF ACIDS AND BASES BY GILBERT NEWTON LEWIS. Gilbert Newton Lewis was a distinguished scientist in 20th century History of Chemistry. His work remains relevant for physical chemistry, organic chemistry and coordination chemistry nowadays. Lewis is well known by his propose for chemical bond, based on electron sharing. In 1923 he published two theoretical explanations for acids and bases: the former collaborating with Bronsted and Lowry and the later in his book Valence and the Structure of Atoms and Molecules (1923). In this book, the role of electron pairs in acid base reactions was highlighted decentering explanations from detachment/transfer of hydrogen ion. As a result, more substances could be classified as acids and bases. Also, in the context of organic and coordination chemistry new interpretations for reaction mechanisms showed up. The paper translated here, Acids and Bases (1938), makes a strong empirical description of acids and bases behavior. Lewis designed phenomenological criteria as speed of neutralization reactions, strength of the species acid-base titrations, and its applications as catalysts. In this manuscript, we carried out a commented translation of Lewis Acids and Bases published in 1938, considering it an inspiring source for research and educational applications for Portuguese speaking countries.","PeriodicalId":49641,"journal":{"name":"Quimica Nova","volume":"1 1","pages":""},"PeriodicalIF":0.8,"publicationDate":"2023-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68271323","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

FORMALDEHYDE ANALYSIS BY SPME ON-FIBER DERIVATIZATION: A STUDY OF THE KINETIC MODELS OF ADSORPTION FOR DIVINYLBENZENE 纤维上spme衍生化法分析甲醛:二乙烯基苯吸附动力学模型的研究

IF 0.8 4区化学

Quimica Nova Pub Date : 2023-08-28 DOI: 10.21577/0100-4042.20230039

S. Dugheri, G. Cappelli, Niccolò Fanfani, Jacopo Ceccarelli, L. Trevisani, Marco Sarti, Donato Squillaci, Elisabetta Bucaletti, R. Gori, N. Mucci, G. Arcangeli

{"title":"FORMALDEHYDE ANALYSIS BY SPME ON-FIBER DERIVATIZATION: A STUDY OF THE KINETIC MODELS OF ADSORPTION FOR DIVINYLBENZENE","authors":"S. Dugheri, G. Cappelli, Niccolò Fanfani, Jacopo Ceccarelli, L. Trevisani, Marco Sarti, Donato Squillaci, Elisabetta Bucaletti, R. Gori, N. Mucci, G. Arcangeli","doi":"10.21577/0100-4042.20230039","DOIUrl":"https://doi.org/10.21577/0100-4042.20230039","url":null,"abstract":"Solid-phase microextraction (SPME) via on-fiber derivatization with O-(2,3,4,5,6-pentafluorobenzyl)-hydroxylamine (PFBHA) and gas chromatographic determination is considered a technique of choice in many analytical fields for formaldehyde (FA) monitoring. Vapor phase adsorption models of experimentally loaded PFBHA on porous divinylbenzene (DVB) SPME were investigated at 60 °C, 35 cm s-1 of air velocity, in a 1-64 min range: with the fiber completely exposed, loaded PFBHA was about 276 µg. Among the models tested, i.e. heat transfer, pseudo-second-order (PSO), Elovich, intra-particle diffusion, extra-particle diffusion and Langmuir, PFBHA adsorption was best fit by the PSO model, showing agreement with experimental data (272 µg). The sampling rate of FA in our conditions, obtained with a permeation tube system, was in agreement with literature (17.4 and 18.3 mL min-1, respectively). Thus, an overall standardization of the sampling phase is presented, leaving the sampling time as the most crucial parameter to be set for future applications.","PeriodicalId":49641,"journal":{"name":"Quimica Nova","volume":"1 1","pages":""},"PeriodicalIF":0.8,"publicationDate":"2023-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68271696","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

ESTUDO DE COMPOSTOS POLIAROMÁTICOS NÃO CONVENCIONAIS E MERCÚRIO NA BAÍA DE TODOS OS SANTOS, BRASIL: AVANÇOS RECENTES E CONTRIBUIÇÃO PARA MELHOR COMPREENSÃO DO AMBIENTE MARINHO 巴西托多斯奥斯桑托斯湾非常规多芳香族化合物和汞的研究:最近的进展和对更好地了解海洋环境的贡献

IF 0.8 4区化学

Quimica Nova Pub Date : 2023-08-07 DOI: 10.21577/0100-4042.20230067

M. Nascimento, N. Menezes, Sabrina T. Martinez, Maria Machado, Gisele da Rocha, Jailson de Andrade

{"title":"ESTUDO DE COMPOSTOS POLIAROMÁTICOS NÃO CONVENCIONAIS E MERCÚRIO NA BAÍA DE TODOS OS SANTOS, BRASIL: AVANÇOS RECENTES E CONTRIBUIÇÃO PARA MELHOR COMPREENSÃO DO AMBIENTE MARINHO","authors":"M. Nascimento, N. Menezes, Sabrina T. Martinez, Maria Machado, Gisele da Rocha, Jailson de Andrade","doi":"10.21577/0100-4042.20230067","DOIUrl":"https://doi.org/10.21577/0100-4042.20230067","url":null,"abstract":"UNCONVENTIONAL POLYAROMATICS COMPOUNDS AND MERCURY IN THE TODOS OS SANTOS BAY, BRAZIL: RECENT ADVANCES AND CONTRIBUTIONS TO BETTER UNDERSTAND OF THEIR ROLE IN THE MARINE ENVIRONMENT. Baía de Todos os Santos (BTS) is the second-largest Brazilian bay; it was the first oil producing region in Brazil, with three large industrial parks in its north-northeast portion. In addition, the BTS has two large ports and a population of around 3 million inhabitants distributed among 14 cities. In the present study, recent studies on contamination by polycyclic aromatic compounds (PACs) and Hg in sediments, water, and biota from the BTS region are presented and critically discussed. Among the PACs, studies evaluating the presence of polycyclic aromatic hydrocarbons (PAHs) and their nitrated (nitro-PAHs), oxygenated derivatives (oxy-PAHs), and those containing atoms of S as a heteroatom (PASHs) are considered, as well as the element Hg distributed in seawater, sediments, and biota. Regarding biomonitoring organisms, recent results on polychaetes, ascidians, and corals are presented. Trends for future studies are presented at the end of the text.","PeriodicalId":49641,"journal":{"name":"Quimica Nova","volume":"1 1","pages":""},"PeriodicalIF":0.8,"publicationDate":"2023-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68272711","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

INVESTIGATION ON THE NATURE AND PROVENANCE OF PAH FOUND IN SEDIMENTS OF THE SOLIMÕES RIVER AND SOME ASSOCIATED LAKES solimÕes河及伴生湖泊沉积物中多环芳烃的性质及来源调查

IF 0.8 4区化学

Quimica Nova Pub Date : 2023-08-07 DOI: 10.21577/0100-4042.20230031

T. D. de Oliveira, A. Scofield, Luana Silva, A. Lopes, A. Wagener

{"title":"INVESTIGATION ON THE NATURE AND PROVENANCE OF PAH FOUND IN SEDIMENTS OF THE SOLIMÕES RIVER AND SOME ASSOCIATED LAKES","authors":"T. D. de Oliveira, A. Scofield, Luana Silva, A. Lopes, A. Wagener","doi":"10.21577/0100-4042.20230031","DOIUrl":"https://doi.org/10.21577/0100-4042.20230031","url":null,"abstract":"The present work aimed at evaluating indicators of hydrocarbon sources to sediments from the Solimões River region, in the central Amazon. The 16PAH, the alkylated homologs and molecular markers were investigated. The entire series of alkylated PAH were present and, in some cases, with a distribution observed when oil residues dominate. Nevertheless, hopanes characterizing immature environments undergoing diagenetic transformation were identified in samples from the Solimões River and in surface as well as in core sediment samples from Preto Lake, in the Coari-Manaus stretch. Investigation suggests early diagenesis of the organic matter confirmed by identifying biogenic markers produced during organic matter transformation. Some of these markers derive from incomplete combustion of biomass and are contained in particulate matter formed during forest burning. In the sediments of an industrial area near the city of Manaus, the entire series of mature hopanes was present indicating anthropogenic source of hydrocarbons. The results so far obtained point out the complexity of PAH source appraisal.","PeriodicalId":49641,"journal":{"name":"Quimica Nova","volume":"1 1","pages":""},"PeriodicalIF":0.8,"publicationDate":"2023-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68271621","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0