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Item Adsorption of organic acids from offshore produced water using microporous activated carbon from babassu pericarp: a low-cost alternative(2023) Mônaco, Felipe Santos; Aguiar, Deborah Victória Alves de; Oliveira, Gerlon de Almeida Ribeiro; Vaz, Boniek Gontijo; Liao, Luciano Morais; Andrade, Laiane Alves de; Ostroski, Indianara ConceiçãoCurrently, in different regions of the world, there is a growth on the rate of produced water for each barrel of oil extracted. Among the compounds observed in this water are naphthenic acids (NAs). Efforts to remove NAs from produced water must comply with local legislation and avoid damage to the environment since NAs have great toxicity. This study aimed to investigate the ability of activated carbon from the pericarp of babassu coconut (Atallea speciosa Mart. ex Spreng.) to act as an absorbent of NAs in commercial and natural (offshore) produced waters. The activated carbon was physically and chemically characterized. The maximum adsorption capacity of commercial NAs at equilibrium obtained experimentally was 25 mg g−1. The activated carbon removed both NAs and other contaminants for produced water, as revealed by infrared and NMR techniques. In high-resolution mass spectrometry analysis, the abundance of the acids in the produced water was in the C9 and C10 range, being favorable for the adsorbent with a microporous structure. For the produced water kinetics experiments a maximum amount of adsorbed compounds of 17.91 mg g−1 was reached, and the time to achieve equilibrium was approximately 180 min. Thus, the results show that activated charcoal from babassu coconut pericarp can be used as an adsorbent and can potentially compete with other adsorbents to remove NAs in an aqueous solution. Also, the separation process can be adopted at a low cost on platforms, complementing the operations of hydrocyclones and flotation.Item Chemical characterization by ultrahigh-resolution mass spectrometry analysis of acid-extractable organics from produced water extracted by solvent-terminated dispersive liquid-liquid microextraction(2021) Aguiar, Deborah Victória Alves de; Silva, Thais; Brito, Talita Pinheiro de; Santos, Gabriel Franco dos; Carvalho, Rogério Mesquita de; Medeiros Júnior, Iris; Simas, Rosineide Costa; Vaz, Boniek GontijoProduced water by the offshore oil industry represents a significant environmental problem due to the high volume generated and its toxicity. Therefore, new methods are necessary to characterize the produced water and, consequently, to provide an appropriate destination. Here, we used solvent-terminated dispersive liquid-liquid microextraction (ST-DLLME) followed by ultrahigh-resolution mass spectrometry (UHRMS) analysis to extract and characterize naphthenic acids (NAs) from produced water (PW). ST-DLLME is based on a ternary mixture of solvents classified as dispersive, extractor, and demulsifying solvents to ensure analyte extraction efficiency. After that, seven solvent systems at three pH values (2, 7, and 10) were used to study the influences of the sample pH and organic-phase polarity. The relationship between pKa and pH affects the equilibrium between ions and molecules in the aqueous phase, impacting the extraction efficiency. The results showed that at pH 2, the extractability of NAs is directly affected by the dielectric constant of the dispersive solvent. Therefore, when dichloromethane was employed as a dispersive solvent, ST-DLLME presented a better performance, and NA species within an extensive DBE range (1 – 8) and range of carbon numbers (C7 – C18) were extracted. At pH 7 and 10, the solvent system that employed cyclohexane as a nonpolar dispersive solvent demonstrated the highest extraction efficiency, whereas nonpolar NA species with a carbon number greater than C22 could be extracted. Moreover, solutions at pH 7 and 10 expressed more comprehensive molecular formulas for the corresponding compounds than those at pH 2. In summary, ST-DLLME has become a valuable analytical tool for extracting NAs from PW since this extraction technique minimizes the consumption of samples and solvents.Item Comprehensive composition and comparison of acidic nitrogen- and oxygen-containing compounds from pre- and post-salt Brazilian crude oil samples by ESI (-) FT-ICR MS(2022) Aguiar, Deborah Victória Alves de; Lima, Gesiane da Silva; Silva, Rodolfo Rodrigues da; Medeiros Júnior, Iris; Gomes, Alexandre de Oliveira; Mendes, Luiz A. N.; Vaz, Boniek GontijoThe discovery of the pre-salt oil field renewed and expanded the outlook of the Brazilian petroleum industry due to the large volume of oil and its composition. The chemical composition characterization of crude oils from different reservoirs is crucial for the petroleum industry. In this study, comprehensive profiles of polar acidic nitrogen- and oxygen-containing compounds were accessed by electrospray ionization (ESI) in negative mode coupled to Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) for a set of five Brazilian crude oil samples from the pre-salt layer, and these were compared to the chemical composition of four crude oils from post-salt reservoirs. The ESI (-) FT-ICR MS data showed that the N-containing compounds present high relative abundance among the heteroatomic compounds identified for pre- and post-salt crude oils, which was more notable for the pre-salt crude oils. Comparing the heteroatomic profiles of the pre- and post-salt crude oils, the N2, NO, and O classes were seen to decrease in relative abundance in the post-salt crude oil, whereas the NO2 and O2 classes increased in relative abundance. The acyclic to cyclic acid (A/C) ratio of the O2 class was used as a parameter to classify the pre- and post-salt crude oils. The high content of acyclic O2-containing compounds (A/C ratio > 1.2) indicated that the pre-salt crude oils are more preserved from microbial alteration, leading to the formation of O2-containing compounds, while an A/C ratio < 0.2 for post-salt crude oils categorized them as more biodegraded. A modified A/C ratio that included aromatic O2 compounds, analyzed in a ternary diagram, was also used to classify the oils according to their families: pre- and post-salt crude oils. Considering the O2-containing compounds with 1, 3, and 5 DBE (double bond equivalents), it was possible to group these oils according to their reservoirs. In addition, alkylphenols with DBE = 4, 5, and 6 also demonstrated a tendency to identify the oils according to their pre- and post-salt reservoirs. The petroleomic approach shown here by comprehensive FT-ICR mass spectrometry analysis is a powerful tool for differentiating crude oils from pre-salt and post-salt reservoirs.Item Determining methamphetamine in urine by molecularly imprinted polymer assisted paper spray ionization mass spectrometry(2021) Brito, Talita Pinheiro de; Aguiar, Deborah Victória Alves de; Silva, Igor Pereira da; Vaz, Boniek GontijoThe usefulness of molecularly imprinted polymer assisted paper spray ionization mass spectrometry (MIP-PSI-MS) for the determination of methamphetamine in urine has been demonstrated. MIP-PSI-MS is a method in which a MIP is synthesized on the surface of a paper, producing a chemically selective paper surface with molecular recognition sites for a target analyte. The analyte is extracted by the MIP substrate, which is posteriorly used for conventional PSI-MS analysis. As methamphetamine is one of the most widely used drugs of abuse in the world, it was selected to be studied in synthetic urine by the MIP-PSI-MS method. Methamphetamine was detected at higher ion signals compared to other different drugs, such as lysergic acid diethylamide (LSD) and cocaine, suggesting that MIP-PSI-MS has a chemical affinity for methamphetamine. In experiments to validate the method, a linear calibration curve was achieved with R-squared (R2) > 0.99. Limit of detection (LOD) and limit of quantification (LOQ) were determined to be 0.8 and 2.8 µg L-1, respectively. Precision (relative standard deviation) and accuracy (relative error) were less than 10%, and the recoveries were close to 100%. The matrix effect was below 10%. These data demonstrate the possibility of using MIP-PSI-MS as an analytical tool for a specific/ selective analysis of methamphetamine in forensic sciences.Item Direct analysis of naphthenic acids in produced water and crude oil by NH2-surface-modified wooden-tip electrospray ionization mass spectrometry(2021) Silva, Thais Aline Mazurok da; Silva, Igor Pereira da; Aguiar, Deborah Victória Alves de; Santos, Gabriel Franco dos; Brito, Talita Pinheiro de; Carvalho, Rogerio Mesquita de; Medeiros Júnior, Iris; Simas, Rosineide Costa; Vaz, Boniek GontijoThis work describes the surface coating of wooden toothpicks with amino groups (NH2) for electrospray ionization mass spectrometry (MS) analysis of naphthenic acids (NAs) in produced water samples and crude oil fractions. NH2 was introduced into the cellulosic material through a silanization reaction using aminopropyltriethoxysilane. An NH2-modified toothpick was inserted into the analyte extraction sample and was subsequently used as an electrospray emitter for MS analysis. The extraction conditions were optimized by analyzing NAs (benzoic acid, 1-naphthoic acid, decanoic acid, 3,5-dimethyladamantane-1-carboxylic acid, and 3,5-dimethyladamantane-1-acetic acid) in pure water, and the best condition was using 5 min of extraction time with the samples under agitation. Modified and unmodified wooden toothpicks were compared, and the intensities of all NAs were higher when using the modified substrates than when using the unmodified ones. Limit of detection (LOD), limit of quantification (LOQ), linearity, precision, and recovery were determined by analyzing decanoic acid in seawater samples. The LOD and LOQ were 2 and 5 μg mL−1, respectively, and a linear correlation (R2 = 0.9927) was obtained with concentrations ranging from 5 to 250 μg mL−1. Precision values ranged from 6 to 13% and recoveries from 89 to 106%. The technique was also employed to analyze three produced water samples, in which decanoic acid was semi-quantified, and the concentrations ranged from 10 to 13 μg mL−1. High abundances of acidic compounds of class O2 with DBEs (double bond equivalents) ranging from 1 to 3 and carbon numbers going from 8 to 12 were detected in the produced water samples. The results suggest that the modification of wooden toothpicks with NH2 might offer a significant advancement in the knowledge of cheap substrates that can improve the sensitivity of analysis of NAs in water samples.Item LC-HRMS/MS-based metabolomics approaches applied to the detection of antifungal compounds and a metabolic dynamic assessment of orchidaceae(2022-11-16) Lima, Gesiane da Silva; Lima, Nerilson Marques; Roque, Jussara Valente; Aguiar, Deborah Victória Alves de; Oliveira, João Victor Ataide; Santos, Gabriel Franco dos; Chaves, Andréa Rodrigues; Vaz, Boniek GontijoThe liquid chromatography–mass spectrometry (LC-MS)-based metabolomics approach is a powerful technology for discovering novel biologically active molecules. In this study, we investigated the metabolic profiling of Orchidaceae species using LC-HRMS/MS data combined with chemometric methods and dereplication tools to discover antifungal compounds. We analyze twenty ethanolic plant extracts from Vanda and Cattleya (Orchidaceae) genera. Molecular networking and chemometric methods were used to discriminate ions that differentiate healthy and fungal-infected plant samples. Fifty-three metabolites were rapidly annotated through spectral library matching and in silico fragmentation tools. The metabolomic profiling showed a large production of polyphenols, including flavonoids, phenolic acids, chromones, stilbenoids, and tannins, which varied in relative abundance across species. Considering the presence and abundance of metabolites in both groups of samples, we can infer that these constituents are associated with biochemical responses to microbial attacks. In addition, we evaluated the metabolic dynamic through the synthesis of stilbenoids in fungal-infected plants. The tricin derivative flavonoid- and the loliolide terpenoidfound only in healthy plant samples, are promising antifungal metabolites. LC-HRMS/MS, combined with stateof-the-art tools, proved to be a rapid and reliable technique for fingerprinting medicinal plants and discovering new hits and leads.Item Polypyrrole-coated needle as an electrospray emitter for ambient mass spectrometry(2020) Araujo, Giovanna Lopes de; Aguiar, Deborah Victória Alves de; Silva, Igor Pereira da; Silva, Lidya Cardozo da; Chaves, Andréa Rodrigues; Vaz, Boniek GontijoPolypyrrole (PPy) is a polymer widely used as an extraction phase due to its ability to perform intermolecular interactions with the analyte, such as acid–base, π–π, dipole–dipole, hydrophobic, and hydrogen bonding. In this manuscript, we report the coating of a stainless steel needle with a PPy film for analyte extraction and subsequent analysis by electrospray ionization mass spectrometry (ESI-MS) under ambient and open-air conditions. The method, named PPy-ESI-MS, was optimized for analysis of 3,4-methylenedioxyamphetamine (MDA) and 3,4-methylenedioxymethamphetamine (MDMA) in synthetic urine. Seven cycles of electrodeposition of the PPy film onto the needle surface, sample at pH 8, and 40 min of extraction of analytes were determined as the best analysis conditions. The analytical performance of PPy-ESI-MS was evaluated for MDA and MDMA compounds. Analytical curves were obtained with R2 > 0.98. Limits of detection (LODs) and limits of quantification (LOQs) were determined as 20 μg L−1 and 70 μg L−1 for MDA and as 25 μg L−1 and 80 μg L−1 for MDMA, respectively. Values of precision were below 17%, and values of accuracy below 5%. The apparent recoveries ranged between 84.5% and 111.3%. In addition, the PPy-ESI-MS method was applied for the analysis of sarcosine in synthetic urine in order to evaluate the performance of the method for another class of compounds. The calibration curve was obtained with R2 > 0.98, along with LOD and LOQ of 30 μg L−1 and 100 μg L−1, respectively. The precision and accuracy values were below 5% and 8%, respectively, and the apparent recoveries close to 100%. This work demonstrates the usefulness of combining an extraction phase with ESI-MS analysis under ambient conditions to determine different classes of small molecules in a complex sample.Item A potential material for removal of nitrogen compounds in petroleum and petrochemical derivates(2021) Carvalho, Matheus Antoniel Félix de; Aguiar, Deborah Victória Alves de; Vaz, Boniek Gontijo; Ferreira, Maria Eugênia de Oliveira; Andrade, Laiane Alves de; Ostroski, Indianara ConceiçãoActivated carbon from coconut shell (Elaeis guineensis), in both crude and chemically modified forms, was evaluated as an adsorbent for removing nitrogen compounds of samples from synthetic and real fuel. The preliminary adsorption tests showed that 97.95 of indoline was removed by sulfuric acid-treated activated carbon (SAAC). The optimum conditions toward adsorption of nitrogen-containing compounds in crude oil (54 °C, 150 rpm and 1.104 g of adsorbent) was evaluated according to the design of experiments (DOE) technique associated with Differential Evolution optimization algorithm and an effective removal of 30.37% of basic nitrogenous compounds present in crude oil was achieved. For comparative effect, the tests were carried out using the previously optimized condition with the vacuum residue, diesel S-500, and diesel S-10, obtaining the removal of 21.56%, 44.44%, and 62.09%, respectively. Complementing the quantitative analysis, the analysis of mass spectrometry confirmed that coconut shell is a potential material for selective adsorption of nitrogenous compounds.Item Quantitative evaluation of non-basic nitrogen containing-compounds in petroleum-derived by direct injection ESI (−) Orbitrap MS(2023) Aguiar, Deborah Victória Alves de; Lima, Gesiane da Silva; Roque, Jussara Valente; Oliveira, João Victor Ataide; Medeiros Júnior, Iris; Gomes, Alexandre de Oliveira; Mendes, Luiz André Nunes; Vaz, Boniek GontijoThe quantification of non-basic nitrogen-containing compounds (NCCs) in petroleum-derived samples has become a critical issue due to the undesirable effects of these compounds on the petroleum industry. In addition, there is a lack of analytical methods that allow the direct quantification of NCCs in these matrices. This paper provides strategies for obtaining quantitative information of NCCs in petroleum-derived samples using direct flow injection electrospray ionization (ESI) (−) Orbitrap mass spectrometry without fractionation steps. Benzocarbazole (BC) quantification was performed using the standard addition method. The method was validated, and all analytical parameters demonstrated satisfactory results in the matrix-mix. Paired Student’s t-test exhibited the matrix effect (95% confidence level, p < 0.05). Limits of detection ranged from 2.94 to 14.91 μg L–1, and the limits of quantification ranged from 9.81 to 49.69 μg L–1. Intraday and interday accuracy and precision were not above 15%. Quantification of non-basic NCCs was carried out based on two approaches. In approach 1, the non-basic NCCs’ total content in petroleum-derived samples was determined by the BC concentration and the total abundance correction. The method presented good performance with the average error of 21, 8.3, and 28% for crude oil, gas oil, and diesel samples, respectively. Approach 2 was based on the multiple linear regression model with regression significant at a 0.05 significance level within average relative errors of 16, 7.8, and 17% for the crude oil, gas oil, and diesel samples, respectively. Then, both approaches successfully predicted the quantification of non-basic NCCs by ESI direct flow injection.Item A simple alternative to prodrug: the hydrochloride salt monohydrate of the prostate anticancer drug abiraterone(2019) Silveira, Rafael Gomes da; Cunha, Beatriz Nogueira da; Tenorio Clavijo, Juan Carlos; Aguiar, Deborah Victória Alves de; Souza, Patricia da Cruz; Vaz, Boniek Gontijo; Ellena, Javier Alcides; Batista, Alzir Azevedo; Martins, Felipe TerraAbiraterone acetate is a first choice prodrug to treat prostate cancer. New higher-solubility multicomponent crystal forms of the active compound abiraterone could substitute for the commonly used acetate prodrug. Here we prepare abiraterone hydrochloride monohydrate, which is the first multicomponent crystal form of this striking prostate anticancer agent. Its solid state characterization by single-crystal X-ray diffraction (SCXRD), infrared (IR) spectroscopy and thermogravimetry (TG) was performed. The only conformational difference in the molecular backbone common to the literature related crystal forms (abiraterone acetate and the free base abiraterone) and our salt resides in the 3-pyridil rotation upon protonation. If the neutral molecules found in the two literature structures are taken as references, this motif is rotated by almost exactly 180° in our protonated abiraterone. Crystal packing also follows the protonation pattern. While in both prodrug and free base there is formation of head-to-tail fashioned one-dimensional chains as the main supramolecular entities, hydrogen bonded sheets are the main supramolecular motifs of abiraterone hydrochloride monohydrate. In addition, the IR spectrum and the TG thermogram of the hydrochloride salt monohydrate are present with characteristics absorption bands and thermal events, being therefore useful as analytical data for control quality purposes of this promising active pharmaceutical ingredient.