Monitoring the degradation and the corrosion of naphthenic acids by electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry and atomic force microscopy

AbstractAlthough the term “naphthenic acids” was originally used to describe acids that contain naphthenic rings, today this term is used in a more general sense and refers to all components in the acid extractable fraction. In crude oil, naphthenic acids exist as a complex mixture of compounds with broad polydispersity with respect to both molecular weight and structure. There has been increasing interest in the naphthenic acids in crude oil because of the corrosion problems that cause during oil refining. Herein, two powerful analytical tools, negative-ion electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry, ESI(-)FT-ICR MS and atomic force microscopy (AFM), were combined to monitor the thermal degradation of naphthenic acids and their corrosion effects on AISI 1020 steel, respectively. Two different acidic crude oils (TAN=2.38 and 4.79mgKOHg−1, and total sulfur=0.7993 and 1.0220wt%) have been submitted to thermal treatment at 280, 300 and 350°C during 2, 4 and 6h, and characterized by ESI(-)-FT-ICR MS, total acid number (TAN), and total sulfur. The AISI 1020 steel was analyzed by scanning electron microscopy (SEM) and AFM. Generally, heating the crude oil at 350°C in a period of 6h, it was observed that a high efficiency (≅80%) and selectivity of thermal decarboxylation process was monitored by decay of TAN (4.79→0.44mgKOHg−1). ESI(-)-FT-ICR MS results showed that naphthenic acid species remained after the heating have DBE ranging 1–12 and carbon number from C15 to C45. AFM topographic profile evidenced that the naphthenic acid corrosion of the crude oil with TAN of 4.73mgKOHg−1 on AISI 1020 steel was profoundly altered and a marked reduction in peak to peak height values (obtained by subtracting the value of the lowest peak by the highest peak in the topographic area examined). Optical images and microphotographs confirmed the presence of irregularities, characterizing the corrosion mechanism as pitting type. The naphthenic corrosion was also evidenced in samples with low TAN value (0.44mgKOHg−1)

Análise de resíduos de disparos de armas de fogo (GSR) usando ICP OES : desenvolvimento de uma nova metodologia analítica

A violência envolvendo armas de fogo representa um grande problema no Estado do Espírito Santo e o desenvolvimento de novos métodos e técnicas que possam auxiliar a polícia na elucidação de homicídios é de fundamental importância para a redução da criminalidade. A espectrometria de emissão óptica com plasma indutivamente acoplado (ICP OES) ganha destaque por ser uma técnica de alta sensibilidade, versátil e mais barata quando comparada com técnicas atualmente utilizadas pela polícia. Desta forma o objetivo deste trabalho foi desenvolver uma metodologia rápida, sensível e confiável para coleta e quantificação de resíduos de disparos de armas de fogo (GSR) utilizando a técnica de ICP OES para medir as concentrações de Chumbo (Pb), Bário (Ba) e Antimônio (Sb) liberados em revólver calibre .38 e pistolas calibres .380 e .40. O trabalho dividiu-se em três capítulos. O capítulo 1 abordou a etapa de otimização da técnica de ICP OES para GSR, no qual foram avaliados os parâmetros operacionais de potência, fluxo do gás de nebulização e taxa de aspiração, utilizando planejamento multivariado composto central. No capítulo 2 foram monitoradas as concentrações de Pb, Ba e Sb em GSR para revólver Taurus® .38, e importantes tópicos foram avaliados, tal como i) a melhor região de coleta da mão do atirador; ii) coletores de fita versus swabs e iii) análise da sensibilidade da técnica de ICP OES em função da distância do atirador quando comparado ao convencional teste colorimétrico. O Pb foi o metal encontrado em maior abundância. Em termos de sensibilidade analítica, uma alta concentração dos três elementos (Pb, Ba e Sb) foi encontrada principalmente nas regiões das pinça-palmar e pinça-dorsal da mão, mesmo com a lavagem da mão do atirador após os disparos, para três e cinco tiros. Na análise entre coletores, os swabs apresentaram melhor sensibilidade na coleta de GSR, além de uma melhor relação custo/beneficio, quando comparado com as fitas. No capítulo 3 foi feito um estudo comparativo entre revólver .38 e pistolas .380 e .40. Foram quantificados Pb, Ba e Sb na mão direita e esquerda dos atiradores para as três armas e realizada uma predição do número de disparos através da construção de modelos de regressão linear múltipla. Foi observado que as concentrações de GSR encontradas nas armas seguem a ordem revólver .38 > pistola .380 > pistola .40, e que é possível predizer o número de disparos de um atirador com boa precisão. Os resultados gerais mostraram importantes informações em análises de GSR, representando um avanço nas investigações forenses.Violence involving firearms is a big issue in the state of Espírito Santo and the development of new methods and techniques that can help the police to elucidate homicides is extremely important to the reduction of crime. Optical emission spectrometry with inductively coupled plasma (ICP OES) stands out as a highly sensitive, versatile and cheap technique when compared to current techniques used by the police. Therefore, the objective of this work was to develop a fast, sensitive and reliable method for collection and quantification of gunshot residues (GSR) using ICP OES to determine the concentrations of lead (Pb), barium (Ba) and antimony (Sb) released by .38 caliber handgun and .380 and .40 caliber pistols. The work was divided into three chapters. In the first, it was discussed the optimization step of the ICP OES technique for GSR, which evaluated the operating parameters of radio frequency power, nebulizer gas flow rate and aspiration rate, using multivariate central composite design. In the second chapter, a study was conducted using Taurus® .38 handgun, which investigated the best residue collection region of the hand in men and women, the feasibility of different collectors for GSR , the comparison of the colorimetric analysis and ICP OES technique for varying distances and the influence of hand washing before and after shots. The results showed that the regions of the thumb and forefinger palm, and the back of the thumb and forefinger are the best collection areas. The pure swab showed better results in terms of cost / benefit and it is possible to obtain concentrations of the metals of interest even with hand washing of shooter. In the third chapter a comparative study between .38 handgun and .380 and .40 pistols it was done. It was quantified Pb, Ba and Sb on the right and left hands of the shooters for the three weapons and held a prediction of the number of shots through the construction of a calibration curve. It was noted the amount of GRS found on the weapons, follows the order .38 handgun>.380 pistol> .40 pistol. Overall results showed important information in GSR analysis, representing a breakthrough in forensic investigations.Capes, Fape

Forensic Ballistics By Inductively Coupled Plasma-optical Emission Spectroscopy: Quantification Of Gunshot Residues And Prediction Of The Number Of Shots Using Different Firearms

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)A new analytical method is proposed for the Pb, Ba and Sb quantifications on gunshot residues (GSR) from firearms using inductively coupled plasma optical emission spectrometry (ICP OES). Lead (Pb), barium (Ba) and antimony (Sb) concentrations in GSR from .38 revolver and .380 and .40 caliber pistols were determined as function of number of shots (from 1 to 5 for the 38 revolver and from 1 to 10 for the pistols) and multiple linear regression model was constructed to determine the number of shots. Also, the sensitivity of ICP OES was compared to conventional colorimetric test in function of distance of shooting (from 0 to 200 cm). Analyzing the effect of distance of shooting over the GSR concentration, the colorimetric test evidenced the presence of a red-pink color only at short distances (from 0 to 10 cm), thus indicating the presence of Pb. For ICP OES analyses, the two analytical methodologies employed presented higher sensitivity than the colorimetric assay, where Pb, Ba and Sb are found from 0 cm ([Pb] = 3158.63 mu g L-1; [Ba] = 85.33 mu g L-1; and [Sb] = 104.90 mu g L-1) to 200 cm ([Pb] = 81.52 mu g L-1; [Ba] = 20.20 mu g L-1; and [Sb] = 8.32 mu g L-1) for the extraction using digestion by microwave. For analyses of GSR using different firearms, good linear correlation coefficients (R-2 > 0.97) were observed between the GSR concentration and the number of shots. Therefore, it was possible to predict the number of shots with good accuracy from Pb, Ba and Sb concentrations using .38 revolver and .40 and .380 caliber pistols. Furthermore, the GSR concentration from different firearms, increased in the following order:.40 pistol > .380 pistol > 38 revolver. (C) 2014 Elsevier B.V. All rights reserved.1181925FAPESConselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES

FT-ICR MS analysis of asphaltenes: asphaltenes go in, fullerenes come out

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Asphaltenes analysis still remains a challenge due to their unknown molecular structure and self-associative behavior. FT-ICR MS analyses using five different ionization methods, ESI, APCI, APPI, LDI and MALDI, in both positive and negative mode were performed. A characteristic and typical behavior was observed for the experiments using LDI(+/-) and MALDI(+/-) FT-ICR analyses: a broadband mass spectrum ranging from m/z 500 to 3000 was observed with a 24 Da interval. This phenomenon was attributed to fullerene cluster formation. The most abundant allotropic form of fullerene, C-60, was observed at m/z 719.99914. These species were not observed in APCI(+)/APPI(+) analyses. This last analysis of asphaltene samples doped with the C-60 solution promptly reveals the typical fullerene ions. LDI(+) analyses of pure C-60 showed condensation products. These results indicate a clusterization of asphaltenes in the LDI/MALDI plume, which showed a highly dependency on the laser power density. The dispersion of LDI results on carbonaceus samples in the literature is associated with the lack of control of these parameters. However, to access the sample composition, APPI and APCI should be more suitable. (C) 2014 Elsevier Ltd. All rights reserved.Asphaltenes analysis still remains a challenge due to their unknown molecular structure and self-associative behavior. FT-ICR MS analyses using five different ionization methods, ESI, APCI, APPI, LDI and MALDI, in both positive and negative mode were perf1314958FAPEG - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE GOIÁSFAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOCAPES - COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIORCNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECoordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)sem informaçãosem informaçãosem informaçãosem informaçãoWe acknowledge FAPEG and PETROBRAS for their financial support. GV acknowledges FAPES and CAPES for fellowships. EVRC acknowledges CNPq for fellowship

PET glycolysis optimization using ionic liquid [Bmin]ZnCl3 as catalyst and kinetic evaluation

Abstract In the present work, the depolymerization of polyethylene terephthalate (PET) was performed by the method of glycolysis with ethylene glycol. The process was carried out using a factorial design in the Box-Behnken optimization model, using a response surface methodology (RSM) in which three factors (time, temperature and mass ratio of ethylene glycol) were studied in three levels of variation (- 1, 0, +1) with two replicates of the center point, totalizing 15 experiments for which the yield of bis (2-hydroxyethyl) terephthalate (BHET) monomers formed in the process was chosen as response. In parallel, the Arrhenius kinetic test was used to determine the apparent activation energy (Ea) for the 1-butyl-3-methylimidazole trichlorozincate ([Bmin]ZnCl3) - catalyst used in the depolymerization process. The products of glycolysis obtained were characterized by spectroscopic techniques (FTIR), (1 H and 13C NMR), thermal analyses (TGA) and (DSC) and Mass Spectrometry LC-MS/MS hybrid Quadrupole-Orbitrap

Dendranthema grandiflorum, a hybrid ornamental plant, is a source of larvicidal compounds against Aedes aegypti larvae

Abstract In hybrid cultivated form, Dendranthema grandiflorum (Ramat.) Kitam., Asteraceae, flowers (Chrysanthemum morifolium Ramat.) were utilized in the production of extracts, which were analyzed for larvicidal activity against Aedes aegypti third instar larvae. Methanol and dichloromethane extracts showed LC50 values of 5.02 and 5.93 ppm, respectively. Using GC–MS, phytochemical analyses of the dichloromethane extract showed the presence of triterpenoids and fatty acids, while flavonoids and caffeoylquinic acids were shown to occur in the methanol extract by ESI Fourier Transform Ion Cyclotron Resonance Mass Spectrometry (ESI-FT-ICR-MS). Triterpenoids and fatty acids are well known insecticidal compounds. From this study, it can be concluded that D. grandiflorum grown for floriculture, as an agribusiness, can have additional applications as raw material for the production of insecticidal products

Detection of Pb, Ba, and Sb in blowfly larvae of porcine tissue contaminated with gunshot residue by ICP OES

Submitted by Liliane Ferreira ([email protected]) on 2018-06-08T14:46:12Z No. of bitstreams: 2 Artigo - Larissa Campos Motta - 2015.pdf: 3336778 bytes, checksum: b3e7af7c6fcb685f85e8b5cf55af69c8 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5)Approved for entry into archive by Luciana Ferreira ([email protected]) on 2018-06-11T12:01:48Z (GMT) No. of bitstreams: 2 Artigo - Larissa Campos Motta - 2015.pdf: 3336778 bytes, checksum: b3e7af7c6fcb685f85e8b5cf55af69c8 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5)Made available in DSpace on 2018-06-11T12:01:48Z (GMT). No. of bitstreams: 2 Artigo - Larissa Campos Motta - 2015.pdf: 3336778 bytes, checksum: b3e7af7c6fcb685f85e8b5cf55af69c8 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2015Lead (Pb), barium (Ba), and antimony (Sb) concentrations were monitored in flies larvae (immature Chrysomya albiceps) contaminated with gunshot residue (GSR) from.40 caliber Taurus pistols during the period of 2 to 12 days after the death of a female pig in decomposition, during the winter, under the influence of rain and high relative humidity. The samples were also analyzed by the colorimetric test using sodium rhodizonate (Feigl-Suter reaction). It was possible to detect and quantify the three metals of interest by inductively coupled plasma-optical emission spectrometry (ICP OES), where the concentrations of all three elements kept practically constant during the putrefaction stage. Minimum ([Pb] = 382.26 gL−1; [Ba] = 140.50 gL−1; [Sb] = 39.18 gL−1) andmaximum ([Pb] = 522.66 gL−1; [Ba] = 190.30 gL−1; [Sb] = 56.14 gL−1) concentrations were found during the third and fifth days after death, respectively. ICP OES presented higher sensitivity in metals determination when compared to the conventional colorimetric test, which showed negative result for the GSR extracts obtained from the immature Chrysomya albiceps

2-(4-IODO-2,5-DIMETOXIFENIL)-N-[(2-METOXIFENIL)METIL]ETAMINA OU 25I-NBOME: CARACTERIZAÇÃO QUÍMICA DE UMA DESIGNER DRUG

Drug trafficking and the introduction of new drugs onto the illicit market are one of the main challenges of the forensic community. In this study, the chemical profile of a new designer drug, 2-(4-iodine-2,5-dimethoxyphenyl)-n-[(2-methoxyphenyl)methyl]etamine or 25I-NBOMe was explored using thin layer chromatography (TLC), ultraviolet-visible spectrophotometry (UV-Vis), attenuated total reflection with Fourier transform infrared spectroscopy(ATR-FTIR), gas chromatography mass spectrometry (GC-MS) and electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry (ESI-FT-ICR MS). First, the TLC technique was effective for identifying spots related to 25C-, 25B- and 25I-NBOMe compounds, all with the same retention factor, Rf ≈ 0.50. No spot was detected for 2,5-dimethoxy-4-bromoamphetamine, 2,5-Dimethoxy-4-chloroamphetamine or lysergic acid diethylamide compounds. ATR-FTIR preserved the physical-chemical properties of the material, whereas GC-MS and ESI-MS showed better analytical selectivity. ESI(+)FT-ICR MS was used to identify the exact mass (m/z428.1706 for the [M + H]+ ion), molecular formula (M = C18H22INO3), degree of unsaturation (DBE = 8) and the chemical structure (from collision induced dissociation, CID, experiments) of the 25I-NBOMe compound. Furthermore, the ATR-FTIR and CID results suggested the presence of isomers, where a second structure is proposed as an isomer of the 25I-NBOMe molecule