Resumo em Inglês:

Capillary electromigration techniques can be understood as the ones used to separate neutral compounds, solvated ions and ionized species, considering the differentiated migration among them when an electrical field is applied within a capillary column filled with a background electrolyte. Several existing capillary electrophoresis setups provide the possibility of developing reliable quantitative assays of inorganic ions, organic acids, fatty acids, amino acids, carbohydrates, nucleic acids, proteins, hormones, vitamins, macromolecules, and more. Therefore, given the chemical complexity of bodily fluid matrices, capillary electrophoresis (CE) and its variations present themselves as an advantageous strategy for enhancing traditional clinical diagnostic methods and for the development of new ones. The recent advances in the study of the human metabolome associated with technological improvements towards medical applications make CE a very useful and versatile technique for clinical laboratory assays. Within this context, this review has the purpose of presenting some traditional methods used for exams of blood, urine, saliva, feces, and sweat, and how CE can be implemented as a real alternative to enable faster, automated, and cost-effective analysis with a comprehensive perspective that shall result in better diagnostic possibilities for patients, being a powerful tool for helping physicians on the precision medicine achievements.

Resumo em Inglês:

This review deals with two-dimensional liquid chromatography (2D-LC) separations encompassing target heart-cut (LC-LC), multiple heart-cut (mLC-LC), non-targeted comprehensive (LC × LC), and selective comprehensive (sLC × LC) analysis. It presents an overview of basic concepts and emphasizes the versatility of the applications gained by going from one-(1D) to two-dimensional (2D) separations. This review also discusses target analysis of achiral and chiral drugs for different applications and the use of 2D-LC in zonal bioaffinity chromatography. Advances in instrumental and column technologies have widened the application of LC × LC and sLC × LC separations, and we will discuss some of them.

Resumo em Inglês:

Bio-oils from biomass pyrolysis have a highly promising potential as biofuels or sources of chemicals. The quantitative analysis of bio-oils is quite difficult and requires many standards. In this study, we developed a methodology using only 16 standards for determining the concentration of 49 compounds, representatives of the main chemical classes commons in bio-oils, using relative response factors (RRF) and analytical curves. Five Pinus sawdust bio-oils were analyzed using a GC-MS-DB-5 capillary column (60 m). SCAN mode (from 45 to 450 Daltons) and retention indices (LPTRI) were used for qualitative analysis. For quantitative analysis, SIM mode was preferred, and analytical curves were constructed from an initial solution at 400 mg g 1 of each of the 16 standards, with concentrations ranging from 1 to 150 mg g 1 added to the internal standard (methyl hexanoate) at 70 mg g 1. After the positive identification and quantification of 9 compounds (among the 16 standards used), the other compounds were quantified using the RRF obtained from a standard solution at 30 mg g 1, considering the similarities with those identified standards. 196 compounds were identified, while 49 compounds were quantified, highlighting the monoaromatic hydrocarbons, naphthalenes, benzofurans, alkyl phenols, and catechols.

Resumo em Inglês:

Parkinson’s disease is a neurodegenerative disorder characterized by progressive loss of dopaminergic neurons. There is substantial evidence that the endocannabinoid system modulates the dopaminergic activity in the basal ganglia, a forebrain system that integrates cortical information to coordinate motor activity regulating signals. In this article, a fused-silica capillary with a molecularly imprinted polymer was developed for in-tube solid-phase microextraction of the endocannabinoid anandamide in plasma samples from Parkinson’s disease patients and further analysis by ultra-high-performance liquid chromatography with tandem mass spectrometry. The molecularly imprinted polymer capillary presented recognition sites with complementary shape, size, and functionality to anandamide. Scanning electron micrographs and Fourier transform infrared spectra illustrated the physical and chemical modification of the printed and non-printed capillary surface. The in-tube solid-phase microextraction ultra-high-performance liquid chromatography with tandem mass spectrometry method presented a linear range from 0.1 to 20 ng mL-1, precision with coefficient of variation values ranging from 1.2 to 13%, and relative standard deviation accuracy ranging from -3.6 to 7.5%. The method developed herein can adequately determine anandamide in plasma samples from Parkinson’s disease patients. By applying the standard addition approach, the anandamide plasmatic concentration in these samples was found to range from 0.2 to 0.4 ng mL-1.

Resumo em Inglês:

This study describes reversed-phase liquid chromatography (RPLC) methods to quantify urinary myoglobin using polymer monolithic columns produced by copolymerization of stearyl methacrylate (SMA) and ethylene glycol dimethacrylate (EDMA). The columns were prepared in the coffins of 1.5 mm internal diameter (i.d.) ethylene tetrafluoroethylene (ETFE) tubing for use in sequential injection chromatography (SIC) and solid phase extraction (SPE), and inside 1.0 mm i.d. Silcosteel® tube for use in narrow-bore liquid chromatography. The monoliths inside the ETFE were produced via UV, whereas thermal polymerization formed the monoliths inside the Silcosteel® tube. The separation of carbonic anhydrase, lysozyme, and myoglobin was demonstrated because they may occur simultaneously in urine samples. Quantification was undertaken by external calibration, and the accuracy was evaluated by the spiking/recovery strategy. The methods exhibited linearity from 5.0 to 60 μg mL-1 (SIC), 2.5 to 50μg mL-1 (high-performance liquid chromatography (HPLC)), and 1.0 to 7.5 μg mL-1 for an SPE-HPLC method. The lowest limits of detection and quantification were 0.13 and 0.43 µg L-1, respectively, obtained after concentrating myoglobin by SPE. Recoveries ranged from 98 to 105%. The low cost, simplicity, reusability, and analytical features provided by these polymeric stationary phases make them affordable alternatives to routine analyses of urinary myoglobin.

Resumo em Inglês:

The physical adsorption of a polymer, poly(3,3,3-trifluoropropylmethylsiloxane), on aluminized silica particles, without any additional procedure for polymer immobilization, was studied for 180 days to evaluate the new chromatographic support. Morphological, structural, and chromatographic evaluations of the stationary phase were assessed. After the 15th day of adsorption, a sufficient polymer amount adsorbs onto the aluminized silica particles to separate mixtures of compounds in reversed-phase mode. However, after the 60th day, the polymer layer adhesion occurs more strongly, self-coating the aluminized silica particles. The self-coated stationary phases after 60 days showed similar chromatographic profiles with low hydrophobicity and more interactions with polar compounds, characteristics arising from the fluorinated polymer. The aluminized silica support firmly adhered to the polymer layer, resulting in a separation material chemically stable at alkaline conditions, suggesting a surface reactivity like other well-established supports without asymmetrical peaks for polar compounds.

Resumo em Inglês:

In the present study, a novel magnetic dispersive solid-phase extraction method using molecularly imprinted polymer synthesized through semi-covalent imprinting approach was developed for cholesterol (CHO) determination in milk samples by high-performance liquid chromatography with diode array detector (HPLC-DAD). The adsorbent named Fe3O4/SiO2/MIP (MIP: molecularly imprinted polymers) was prepared through sol-gel polymerization of 3-(triethoxysilyl)propyl isocyanate (ICPTES) covalently bonded to CHO with tetraethoxysilane (TEOS), in the presence of Fe3O4/SiO2 particles. The adsorbent was characterized by attenuated total reflection Fourier transform infrared (ATR-FTIR), X-ray diffraction (XRD), dynamic light scattering (DLS) and scanning electron microscopy (SEM). The proposed molecularly imprinted polymer-based magnetic dispersive solid-phase extraction method (MIP-MDSPE) was based on vortex-assisted preconcentration of 10.0 mL of CHO solution in chloroform as donor phase using 10.0 mg of Fe3O4/SiO2/MIP during 60 s. After this step, the magnetic particles were collected using a permanent magnet and the vortex-assisted elution was carried with 500 µL of ethanol during 180 s. A wide analytical curve ranging from 38.5 to 25000 µg L-1 (determination coefficient (R2) = 0.998) and low limits of detection (LOD) and quantification (LOQ) 11.5 and 38.5 µg L 1, respectively, were obtained. Milk samples (whole and reduced-fat milk) were subjected to MIP-MDSPE method after saponification reaction followed by CHO extraction with chloroform. Using external calibration, the CHO concentration ranged from 99.2 (reduced-fat milk) to 397.6 mg kg 1 (whole milk) and the accuracy was attested by addition and recovery tests (92 to 97%).

Resumo em Inglês:

The aim of this study was to preliminary evaluate the lipid profile alterations on Pitcairnia flammea leaves based on variations in solvent proportion and ultrasonic ice bath extraction time, followed by a lipid class-enriched analysis employing chemometric techniques. Ultra-high performance liquid chromatography coupled to electrospray ionization mass spectrometry (UHPLC-ESI-MS) was used to acquire raw data and MS-DIAL and MetaboAnalyst platforms were used to perform data preprocessing and statistical analysis. The statistical analysis of UHPLC-ESI-MS data in both ionization modes enabled the visualization of a trend distribution based on extraction time. Furthermore, we were able to establish that the solvent proportion had a greater impact on group separation in data samples extracted for 30 min versus 10 and 20 min. Moreover, diacylglycerol or/and lysophosphatidylcholine are lipid subclasses that can be favored depending on the extraction time in the mass spectrometry analyses using positive electrospray ionization mode.

Resumo em Inglês:

An extraction phase based on hydrogel disks of polyvinyl alcohol and pectin was developed, characterized, and evaluated for the extraction of four endocrine disruptors (methylparaben, ethylparaben, propylparaben and butylparaben) in free form in human urine samples with subsequent determination by liquid chromatography coupled with a diode array detector (LC-DAD). The proposed hydrogel showed easy synthesis, was made of low-cost and non-toxic polymers, and showed that it has an amphiphilic character. Gels with lower swelling indexes (175%) and more concentrated dispersions of polymers (P20PC2.0) showed lower relative standard deviation (RSD) values. Under optimized solid phase extraction (SPE) conditions, the LC-DAD method presented limits of quantification of 0.1 µg mL1, accuracy values ranged from 101.3 to 118.2%, while the inter-assay precision ranged from 1.5 to 17.4%. In addition, the polyvinyl alcohol (PVOH)/pectin-based material presented the possibility of reuse at least 15 times, without presenting carryover effect and physical degradation. In this way, the hydrogel shows promise for the extraction of organic compounds with different polarities in biological matrices.

Resumo em Inglês:

Investigating specialized plant metabolites, traditionally referred to as ‘secondary metabolites’ present in leaf extracts of cashew trees (Anacardium occidentale) resistant and susceptible to anthracnose disease was carried out using metabolomics combined with chemometric tools. We used clones of dwarf-cashew with the following variations of characteristics: resistant and healthy (CCP 76, BRS 226, BRS 189), susceptible and healthy (BRS 265), and another clone also susceptible but affected by the disease (BRS 265). The UPLC-QTOF-MSE (ultra performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry) analysis of the leaves of Anacardium clones allowed us to annotate a total of 39 metabolites. The multiple orthogonal partial discriminant analysis of the least-squares (OPLS-DA) allowed twelve metabolites to be potential biomarkers of differentiation among the clones studied. Namely, the triene-(17:3)-anacardic acid found on CCP 76 and BRS 189 clones, respectively, is the main candidate for biomarker of resistance. While catechin, B-type procyanidin isomers, and procyanidin dimer monogallate identified in BRS 265 are significant potential biomarkers of susceptibility.

Resumo em Inglês:

Lung cancer is one of the main causes of death for thousands of people yearly around the world. Biomarker aldehydes, such as hexanal and heptanal, are compounds related to the development of lung cancer, which can be detected in the early stages of this disease. A methodology was proposed to determine these aldehydes in urine, with a new configuration associated with the sample preparation step. A novel strategy with a parallel-disposable pipette extraction (DPX)-cork device was used, offering a fast and affordable extraction methodology with analysis performed by high performance liquid chromatography with diode array detector. In optimization steps, multivariate and univariate designs were applied, providing the following conditions: urine sample centrifuged at 3500 rpm for 15 min, 30 µL and 6 min of dinitrophenylhydrazine impregnation, 10× urine diluted in ultrapure water, pH adjusted to 4.8, 7 extraction cycles with 1.5 min each, 30 mg of cork, 2 desorption cycles and solvent acetonitrile with 300 µL. Limits of detection were 0.13 ng mL-1 for both analytes and limits of quantification were 0.40 and 0.41 ng mL-1 for hexanal and heptanal, respectively. Intraday and interday precisions ranged from 4 to 21%. Relative recoveries ranged from 86 to 107%, assessed at three concentrations. Urine samples were analyzed, but the presence of aldehydes was not detected.

Resumo em Inglês:

Among stimulant drugs, cocaine deserves attention due to its high rates of seizures worldwide. This work presents the synthesis and characterization of hybrid molecularly imprinted polymers (MIPs) for use in preparing biological samples using a homemade microextraction in a packed sorbent device to extract cocaine. The MIPs synthesized using caffeine and cocaine as templates have been compared. Caffeine was used due to its low value and be easier to obtain than cocaine. Additionally, restricted access molecularly imprinted polymers (RAMIPs) were also produced for comparison purposes. The polymeric materials were characterized using scanning electron microscopy, textural analysis, Fourier transform infrared spectroscopy, and cross polarization/ magic angle spinning 13C nuclear magnetic resonance. The method optimization was performed using linear ion trap mass spectrometer to evaluate the effects of sample pH, type of eluent, washing solvent, adsorption cycles, and eluent volume. In the optimized method, RAMIPs indicated better cocaine extraction compared to MIPs. The quantitative study demonstrated that the developed method was able to accurately quantify cocaine in urine samples with values close to actual concentrations.

Resumo em Inglês:

The herbicide glyphosate is the most widely used pesticide worldwide. Glyphosate and its major metabolite, aminomethylphosphonic acid (AMPA), have been frequently found in water samples. The widely used methods for determining these compounds are expensive and environmentally unfriendly due to reagent consumption for derivatization. Another possibility is the use of classic ion chromatography, albeit with low sensitivity and subject to interferences. Therefore, this study aimed to develop a method to directly and simultaneously determine glyphosate, AMPA, and common inorganic anions in water samples using gradient capillary ion chromatography without sample pre-treatment and derivatization. The proposed method was validated, presenting adequate linearity for glyphosate and AMPA with a determination coefficient (r2) > 0.998. Recoveries ranged from 94 to 105% and 79 to 113% for glyphosate and AMPA, respectively, with a relative standard deviation < 10%. The practical method limits of detection and quantification for both glyphosate and AMPA were 7.5 and 25 µg L 1, respectively. The method presented satisfactory results for the anions fluoride, chloride, bromide, nitrite, nitrate, phosphate, and sulfate, with limits of detection ranging from 7.5 to 200 µg L-1. Application of the method in water samples proved simple, efficient, and cost-effective, enabling the monitoring of these analytes in different water matrices.

Resumo em Inglês:

In 2019, large amounts of oil reached the northeast coast of Brazil, causing damage to the environment and the local economy, especially in the state of Pernambuco. In order to correlate with possible sources, investigation was made of the geochemical biomarkers of the oils using “gold standard” forensic protocols from the European Committee for Standardization (CEN). The biomarkers study was improved by using gas chromatography-tandem mass spectrometry (GC-MS/MS), rather than the standard protocol that suggests use of the selected ion monitoring (SIM) method. Analysis was made of thirteen oil samples from the Pernambuco coast, in order to identify their degrees of similarity and the possible presence of oils from unreported spills. The use of eighteen diagnostic ratios and multivariate analysis revealed a cluster formed by eleven samples with biomarker distributions typical of oil from the 2019 spill. However, two samples had anomalous fingerprints, especially due to the absence of the 18α(H)-oleanane and 18β(H)-oleanane isomers. Both the CEN protocol applied for the classical biomarkers and a comprehensive Fourier transform mass spectrometry (FT-MS) analysis of polar compounds confirmed the dissimilarities between the samples. The findings suggested that these two oils could have originated from an event unrelated to the mysterious 2019 spill.

Resumo em Inglês:

Fresh coconut (Cocos nucifera) water, a popular beverage in tropical countries, is often exposed to pesticide contamination due to agricultural practices. Thus, this work proposed the simultaneous determination of 36 pesticides in fresh coconut water samples using liquid-liquid extraction, drying assisted by a household microwave oven, and gas chromatography-mass spectrometry (GC-MS) analysis. Limits of detection varied from 5.4 (disulfoton) to 9.6 ng L-1 (parathion-methyl). Nine pesticide residues were detected (dimethoate, γ-HCH, β-HCH, 4,4’-dichlorodiphenyldichloroethylene, endosulfan II, 4,4’-dichlorodiphenyldichloroethane, 4,4’-dichlorodiphenyltrichloroethane, endrin ketone, and methoxychlor) with concentrations from < limit of quantification to 5,768.34 ± 1.64 ng L-1. Dimethoate was quantified in all samples, indicating its recent use. The proposed methodology offers several advantages, including the use of small sample volumes and solvent extraction, which eliminates the need for costly cartridges and reduces waste production. Additionally, the obtained results can be valuable for regulatory agencies, aiding in the mitigation of environmental damage and the protection of human health.

Resumo em Inglês:

The main objective of this work was to develop and validate an analytical method using solid-liquid extraction and liquid chromatography coupled with mass spectrometry in tandem (LC-MS/MS) for the simultaneous determination of the herbicide 2-(2,4-dichlorophenoxy)acetic acid (2,4-D) and the insecticide fipronil and its degradation products, fipronil sulfone and fipronil sulfide in different types of soil from Brazil (Oxisol and Entisol). Solid-liquid extraction was performed in two cycles using 20 mL of dichloromethane per cycle and sonication. The extraction efficiency of 2,4-D was more influenced by soil composition than the other compounds. The limits of quantification of the method were between 0.015 and 0.75 mg kg-1 and recovery values from 61 to 118%, with a maximum relative standard deviation (RSD) value of 4%. The method was further applied to over 500 real soil and sediment samples. 2,4-D and fipronil concentrations varied from 0.03 to 1145 µg kg-1 and 1.1 to 282 µg kg-1, respectively.

Resumo em Inglês:

Pheromones are essential for colony organization in honeybees. The pheromones 9-ODA ((E)-9-oxodec-2-enoic acid) and 9-HDA ((E)-9-hydroxydec-2-enoic acid), produced by the mandibular gland of the queen, have various functions within the colony, including inhibition of ovarian development of workers, attraction of swarms, and stabilization of the cluster group. An example of reaction of the colony to adverse conditions is absconding, which is defined as mass exit of all of the adult individuals, leaving even brood and food. In this study, the pheromones 9-ODA and 9-HDA were determined in virgin and normal mated, egg-laying European Carniolan and Africanized queens, as well as in mated queens that were in absconding colonies, using liquid chromatography with UV detection developed methodology. Absconding was induced by maintaining free-flying five-standard-Langstroth-frame colonies in a chamber artificially heated to 45 ºC. The obtained results showed that the amount of 9-ODA in Africanized queens (6.56 µg bee-1) is very low compared with European queens. However, large amounts of 9-HDA were found in the queens of absconding Africanized swarms (107.4 µg bee-1). According to our results, the quantities of 9-ODA and 9-HDA in Africanized honeybees in Brazil may be contributing to the high rates of absconding, promoting low effect of stabilizing agent, and high effect of attraction of dispersers cluster.

Resumo em Inglês:

The tomato (Solanum lycopersicon L.) crop has great economic relevance, being one of the most processed agricultural products worldwide. Some pesticides are chemically stable and can remain in food even after processing. In this context, the objective of this work was to analyze food products derived from tomatoes (extract, sauce and ketchup), regarding the levels of pesticide residues. Fifteen samples were acquired from Vale do Jaguaribe, Ceará, Brazil. Six pesticides (bifenthrin, chlorothalonil, chlorpyrifos, cyfluthrin, pyriproxyfen, trifluralin) authorized by Agência Nacional de Vigilância Sanitária (Anvisa) for tomato cultivation were selected for the study. QuEChERS (quick, easy, cheap, effective, rugged, safe) extraction and gas chromatography coupled to mass spectrometry (GC-MS) were used in method validation, according to the recommendations of SANTE 11312/2021 guidelines. Statistical analyses of linearity showed that the six pesticides studied were classified as heterocesdastic. Limits of detection (LOD) and quantification (LOQ) values (0.01-0.03 and 0.03-0.10 mg kg-1, respectively) were below the established maximum residue limits (MRLs) for tomatoes. Accuracy and precision (78-121 and 2.3-16.7%, respectively) were satisfactory. The results indicated that among the 15 analyzed samples, one active ingredient was detected (0.05 mg kg-1) in a tomato sauce sample, lower than MRLs (Anvisa 0.15 mg kg-1 and FAO 0.3 mg kg-1). The results show the relevance of monitoring pesticide residues in tomato-derived products and the validation of new methodologies for food control.