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1.
Zhongguo Shi Yan Xue Ye Xue Za Zhi ; 28(4): 1316-1320, 2020 Aug.
Artigo em Chinês | MEDLINE | ID: mdl-32798419

RESUMO

OBJECTIVE: To explore the abnormal hemoglobinopathy in couples of child-bearing age in Chongqing. METHODS: A total of 34 800 subjects of child-bearing age were screened for thalassemia by using capillary electrophoresis from January 2015 to September 2018. PCR-flow cytometry fluorescence hybridization assay was used to detect the common thalassemia gene deletions and mutations. RESULTS: 8 kinds of abnormal hemoglobinopathy were detected in 200 cases from 34 800 subjects of child-bearing age, the detection rate was 0.57% in couples of child-bearing age in Chongqing: Among 200 cases of abnormal hemoglobin pathy, Hb E was found in 90 cases (accounting for 45.0%), and Hb D in 25 cases (accounting for 12.5%). Hb NewYork was found in 25 cases (accounting for 12.5%). HbJ-bangkok was found in 25 cases (accounting for 12.5%), and Hb Q-Thailand in 16 cases (accounting for 8.0%). Hb Hope was detected in 15 cases (accounting for 7.5%). Hb S was detected in 3 cases (accounting for 1.5%). Hb Hasharon was detected in 1 case (accounting for 0.5%). The mean corpuscular volume (MCV) and mean corpuscular hemoglobin (MCH) of Hb E and Hb Q-Thailand were lower than normal reference intervals. CONCLUSION: The detection rate of abnormal hemoglobinopathy in Chongqing is higher than the average level in China. Capillary electrophoresis can effectively screen abnormal hemoglobinopathy, which is great significant for aristogenesis and improvement of population quality.


Assuntos
Hemoglobinopatias , Hemoglobinas Anormais , Talassemia , Criança , China , Eletroforese Capilar , Humanos , Tailândia
2.
J Chromatogr A ; 1626: 461384, 2020 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-32797857

RESUMO

More and more various chemical media are being applied in enantioseparation; among them, ionic liquids (ILs) have attracted the long-term attention in this decade as green designable solvents. This paper provides comprehensive overview for the applications of ILs in chiral extraction, gas chromatography, liquid chromatography, capillary electrophoresis and other techniques for enantioseparation. Additionally, the important resolution mechanisms based on ILs have also been summarized and discussed. This review focuses on the latest development of enantioseparation methods by using ILs in various modes, leading to meaningful and valuable information to related fields and thus promotes further research and application of reported methods.


Assuntos
Cromatografia Gasosa/métodos , Cromatografia Líquida de Alta Pressão/métodos , Eletroforese Capilar/métodos , Líquidos Iônicos/química , Ligantes , Extração Líquido-Líquido , Extração em Fase Sólida , Estereoisomerismo
3.
J Chromatogr A ; 1626: 461392, 2020 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-32797861

RESUMO

Two sets of polystyrene nanoparticles (PSNPs) with comparable core sizes but different carboxyl group densities were made and separated using asymmetric flow field flow fractionation (AF4), capillary electrophoresis (CE), and the off-line hyphenation of both methods. Our results revealed the significant potential of two-dimensional off-line AF4-CE hyphenation to improve the separation and demonstrated for the first time, the applicability of CE to determine the functional group density of nanoparticles (NPs). Compared to the result acquired with conductometric titration, the result obtained with synthesized 100 nm sized PSNPs revealed only a slight deviation of 1.7%. Commercial 100 nm sized PSNPs yielded a deviation of 4.6%. For 60 nm sized PSNPs, a larger deviation of 10.6% between both methods was observed, which is attributed to the lower separation resolution.


Assuntos
Eletroforese Capilar/métodos , Fracionamento por Campo e Fluxo/métodos , Nanopartículas/química , Poliestirenos/química , Tamanho da Partícula , Dodecilsulfato de Sódio/química , Espectrofotometria
4.
J Chromatogr A ; 1628: 461448, 2020 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-32822987

RESUMO

During a screening of cyclodextrins (CDs) as chiral selectors for the separation of daclatasvir (DCV) and its enantiomer by capillary electrophoresis (CE), an unusual phenomenon for CDs was observed, that is two peaks with a plateau in between using γ-CD as chiral selector. The same result was encountered when enantiopure DCV was injected or when analyzing a sample containing enantiopure DCV and γ-CD in a CD-free background electrolyte. Peak coalescence was observed at 45°C and at a pH above 3.5. Two peaks with a plateau were also observed for DCV stereoisomers as well as a structural analog. However, only a single peak was detected if one or both amino acid moieties of DCV were lacking. Nuclear magnetic resonance (NMR) experiments including Nuclear Overhauser effect-based methods showed that in solution DCV adopted a folded conformation in which the isopropyl side chain of the valine residues pointed toward the aromatic rings of DCV. Moreover, NMR unequivocally demonstrated the simultaneous formation of DCV-γ-CD inclusion complexes with 1:1 and 2:1 stoichiometry, which was corroborated by mass spectrometry. In both complexes, DCV also adopted a folded structure. The RSSR-diastereomer of DCV as well as an analog lacking one of the amino acid moieties also formed 1:1 and 2:1 complexes with γ-CD although a plateau was only observed in the case of the RSSR-diastereomer. As shown by CE-MS, both DCV-γ-CD complexes surprisingly comigrated as the first peak, while the second migrating peak represents non-complexed DCV.


Assuntos
Imidazóis/química , gama-Ciclodextrinas/química , Eletroforese Capilar , Espectroscopia de Ressonância Magnética , Espectrometria de Massas , Conformação Molecular , Estereoisomerismo
5.
J Chromatogr A ; 1627: 461375, 2020 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-32823120

RESUMO

Since decades, cyclodextrins are one of the most powerful selectors in chiral capillary electrophoresis for the enantioseparation of diverse organic compounds. This review concerns papers published over the last decade (from 2009 until nowadays), dealing with the capillary electrophoretic application of single isomer cyclodextrin derivatives in chiral separations. Following a brief overview of their synthetic approaches, the inventory of the neutral, negatively and positively charged (including both permanently ionic and pH-tunable ionizable substituents) and zwitterionic CD derivatives is presented, with insights to underlying structural aspects by NMR spectroscopy and molecular modeling. CE represents an ideal tool to study the weak, non-covalent supramolecular interactions. The published methods are reviewed in the light of enantioselectivity, enantiomer migration order and the fine-tuning of enantiodiscrimination by the substitution pattern of the single entity selector molecules, which is hardly possible for their randomly substituted counterparts. All the reviewed publications herein support that cyclodextrin-based chiral capillary electrophoresis seems to remain a popular choice in pharmaceutical and biomedical analysis.


Assuntos
Ciclodextrinas/química , Eletroforese Capilar/métodos , Concentração de Íons de Hidrogênio , Espectroscopia de Ressonância Magnética , Modelos Moleculares , Estereoisomerismo
6.
J Chromatogr A ; 1626: 461344, 2020 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-32797824

RESUMO

The applicability of capillary zone electrophoresis (CZE) for the separation of the deamidated forms of insulin has been studied. 50 mM NH4Ac (pH=9) with 20 % v/v isopropylalcohol was found optimal for efficient separation of insulin from its even 10 deamidated forms. The developed method was efficiently applied for monitoring the degradation rate of insulin and the formation of different deamidation isoforms. Two months after the acidification more than thirty peaks can be observed in the electropherogram, because degradation products other than deamidated components were formed as well. The recorded mass spectra enabled us to assign the exact mass of the components, and thus the identification of insulin isoforms could be accomplished. We think that this study provides useful information on how the determination of several deamidation forms can be carried out with CE-MS, but the identification of the exact position of deamidation sites in the insulin molecule remains a challenge.


Assuntos
Eletroforese Capilar/métodos , Insulinas/análise , Humanos , Concentração de Íons de Hidrogênio , Espectrometria de Massas , Isoformas de Proteínas/análise , Temperatura
7.
J Virol Methods ; 284: 113937, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32659241

RESUMO

Due to the huge demand for SARS-Cov-2 determination,alternatives to the standard qtPCRtestsare potentially useful for increasing the number of samples screened. Our aim was to develop a direct fluorescent PCR capillary-electrophoresis detection of the viral genome. We validated this approach on several SARS-Cov-2 positive and negative samples.We isolated the naso-pharingealRNA from 20 positive and 10 negative samples. The cDNA was synthesised and two fragments of the SARS-Cov-2 were amplified. One of the primers for each pair was 5´-end fluorochrome labelled. The amplifications were subjected to capillary electrophoresis in ABI3130 sequencers to visualize the fluorescent peaks.The two SARS-Cov-2 fragments were successfully amplified in the positive samples, while the negative samples did not render fluorescent peaks. In conclusion, we describe and alternative method to identify the SARS-Cov-2 genome that could be scaled to the analysis of approximately 100 samples in less than 5 h. By combining a standard PCR with capillary electrophoresis our approach would overcome the limits imposed to many labs by the qtPCR and increase the testing capacity.


Assuntos
Betacoronavirus/isolamento & purificação , Técnicas de Laboratório Clínico/métodos , Infecções por Coronavirus/virologia , Eletroforese Capilar/métodos , Pneumonia Viral/virologia , Reação em Cadeia da Polimerase/métodos , Sequência de Bases , Betacoronavirus/genética , Infecções por Coronavirus/diagnóstico , Primers do DNA/genética , DNA Complementar/genética , Genoma Viral , Humanos , Técnicas de Amplificação de Ácido Nucleico/métodos , Pandemias , Pneumonia Viral/diagnóstico , Sensibilidade e Especificidade
8.
J Chromatogr A ; 1624: 461215, 2020 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-32540065

RESUMO

A method for the preparation of an on-column ESI emitter used as the sheathless interface for coupling capillary electrophoresis (CE) with mass spectrometry (MS) was developed. The emitter was directly fabricated at the outlet end of the separation capillary which was etched with HF solution to a symmetrical tip. The tip was covered with a small piece of gold foil which was fixed by epoxy resin glue for electrical contact. Such a prepared ESI emitter can produce a stable ESI signal over the wide range of flow rate from 50 nL/min to 800 nL/min. The performance of the CE-MS with the sheathless interface was evaluated by using the separation of four alkaloids. It was found that the strong electroosmotic flow produced by the multiple polyelectrolyte coating on the capillary is necessary for maintaining a stable MS signal. Effect of the running buffer composition, concentration and the CE separation voltages on the ESI signal strength were investigated. The absolute detection limits for the alkaloids was determined as fmol level. Moreover, the CE-MS was applied for the analyses of trypsin digestion of cytochrome C and small molecular organic anions. The emitter performed very stable with a lifetime of at least 180 h.


Assuntos
Ouro/química , Dióxido de Silício/química , Espectrometria de Massas por Ionização por Electrospray/métodos , Alcaloides/análise , Eletroforese Capilar , Limite de Detecção , Polieletrólitos/química
9.
Zhongguo Shi Yan Xue Ye Xue Za Zhi ; 28(3): 1012-1018, 2020 Jun.
Artigo em Chinês | MEDLINE | ID: mdl-32552974

RESUMO

OBJECTIVE: To develop an automated chimeric analysis and reporting platform based on short tandem repeat (STR) and capillary electrophoresis methods for allogeneic hematopoietic stem cell transplantation (allo-HSCT) so as to improve work efficiency. METHODS: Apache, MySQL, PHP and HTML5 were used to build the database and interface. The STR locus geno typing and chimeric analysis logic and flow were set up on the basis of STR rules and capillary electrophoresis. STR genotyping and 194 times of chimeric testing data of 100 patients after allo-HSCT were used to test the platform for automatic STR locus genotyping, chimeric calculation and report generation. RESULTS: The established platform could realize the functions of STR locus customization, STR genotype determination, automatic chimeric analysis, and detection information database management, which can automatically generate an integrated report including multiple sequential chimeric results and trend graphs for the same patient and can be accessed and used simultaneously by different users through different browser interfaces. The results of automated analysis by the platform are completely consistent with that of manual analysis by experienced technicians, and the possibility of manual analysis error is reduced through automation. The time required for automatic analysis using this platform is approximately 1/6-1/5 of manual analysis. CONCLUSION: The automatic analysis platform built in this study is operation stable and reliable in analysis results, which can improve work efficiency and report connotation, thus worthing popularized and applicable.


Assuntos
Transplante de Células-Tronco Hematopoéticas , Eletroforese Capilar , Genótipo , Humanos , Repetições de Microssatélites , Doadores de Tecidos
10.
J Chromatogr A ; 1623: 461209, 2020 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-32505293

RESUMO

In most cases, determination of binding constant for analyte-cyclodextrin complexes in capillary electrophoresis is investigated by affinity capillary electrophoresis using a UV detector (ACE-UV). The limitations induced by the UV-detector include : (i) the difficulty of dealing with poor chromogenic analytes and more generally with any analyte presenting strong affinity towards the cyclodextrin (CD), i.e. for which the prerequisite to work with analyte concentration much smaller than those of the CD is difficult to fulfill (ii) the impossibility of studying non-chromogenic analyte. In this paper, two simple methodologies were developed to overcome these limitations. Regarding the analytes which present poor UV-absorbance and/or very high CD-affinity, a methodology using an algorithmic data treatment and taking into account the real analyte concentration in the capillary at the determined migration times allows to correctly estimate the binding constants, even if the experimental prerequisite ([analyte]<<[CD]) is not complied. Moreover, it is proved that classical linearization treatment by picking the migration time of the infinite diluted analytes (at the start of the peak) also provide satisfactory results. Regarding UV-transparent analyte, a competitive methodology combined with algorithmic data treatment allows the determination of their affinity towards cyclodextrins. Last, the applicability of the described competitive method is extended to the study of interaction between two neutral partners, which is another well-known limitation of ACE.


Assuntos
Ciclodextrinas/química , Eletroforese Capilar/métodos , Raios Ultravioleta , Ibuprofeno/análise , Cinética , Modelos Lineares , Termodinâmica
11.
J Chromatogr A ; 1624: 461232, 2020 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-32540073

RESUMO

The separation of the enantiomers of mepromazine, promethazine, thioridazine and alimemazine was studied by nonaqueous capillary electrophoresis in the presence of cyclodextrins using 1 M acetic acid and 50 mM ammonium acetate in methanol as background electrolyte. Heptakis(2,3-di-O-acetyl-6-O-sulfo)-ß-cyclodextrin, heptakis(2,3-di-O-methyl-6-O-sulfo)-ß-cyclodextrin (HDMS-ß-CD) and octakis(2,3-di-O-methyl-6-O-sulfo)-γ-cyclodextrin were the most effective chiral selectors for mepromazine, promethazine and alimemazine. Subsequently, a method for the determination of dextromepromazine as chiral impurity of levomepromazine was developed employing quality by design principles. Using HDMS-ß-CD as selector, a fractional factorial resolution V+ design was employed for evaluating the knowledge space, while a central composite face centered design provided further method optimization and the basis for the computation of the design space by Monte Carlo simulations. The final experimental conditions included a 30/40.2 cm fused-silica capillary with 75 µm inner diameter and a background electrolyte composed of 0.75 M acetic acid and 55 mM ammonium acetate in methanol containing 27.5 mg/mL HDMS-ß-CD. The applied voltage was 22 kV and the capillary temperature was 15°C. Following method robustness testing via a Plackett-Burman design, the method was validated for dextromepromazine in the range of 0.01 to 3.0 % relative to a concentration of 0.74 mg/mL levomepromazine and applied to the analysis of reference standards of the European Pharmacopoeia and commercial tablets. The assay also allowed the detection of levomepromazine sulfoxide although the quantitation of the compound was hampered by the poor peak shape of the late migrating diastereomer.


Assuntos
Eletroforese Capilar/métodos , Metotrimeprazina/análise , Fenotiazinas/química , Fenotiazinas/isolamento & purificação , Metotrimeprazina/análogos & derivados , Metotrimeprazina/química , Metotrimeprazina/isolamento & purificação , Probabilidade , Padrões de Referência , Reprodutibilidade dos Testes , Estereoisomerismo
12.
J Chromatogr A ; 1623: 461158, 2020 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-32505274

RESUMO

In the present study, the enantioseparation of the ll- and dd-enantiomers of the dipeptides Ala-Phe, Ala-phenylglycine (Phg), Ala-homoPhe, Ala-ß-Phe, Gly-Phe and ß-Ala-Phe was studied by capillary electrophoresis in the presence of native α-, ß- and γ-cyclodextrin (CD) as well as their methyl and hydroxypropyl derivatives. Separations were performed under standardized conditions in fused-silica capillaries at pH 2.5, 3.5 and 9.5. All analyte enantiomers could be separated at acidic pH under at least one of the experimental conditions. ß-CDs proved to be more universal chiral selectors than α- and γ-CDs. Only few alkaline conditions led to an enantioseparation. For a given dipeptide, the enantiomer migration order depended on the type of CD with regard to cavity size and degree of substitution. Little effect was found with regard to the structure of the dipeptides. pH-dependent reversal of the enantiomer migration order upon increasing the pH from 2.5 to 3.5 was observed for all dipeptides with at least one of the ß-CD derivatives. In the case of ß-CD, analysis of the complexation constants and the apparent limiting mobilities of the diastereomeric peptide enantiomer-CD complexes revealed, that the enantiomer migration order of Ala-Phe, Ala-homoPhe and Ala-ß-Phe was determined by the stereoselective complexation by ß-CD at pH 2.5. At pH 3.5 opposite chiral recognition of the enantiomers by ß-CD was found for Ala-Phe and Ala-ß-Phe resulting in the reversed migration order. In contrast, chiral recognition did not change in the case of Ala-homoPhe, but reversal of the enantiomer migration order was based on the apparent mobility of the diastereomeric analyte-CD complexes.


Assuntos
Ciclodextrinas/química , Dipeptídeos/química , Eletroforese Capilar/métodos , Dipeptídeos/isolamento & purificação , Concentração de Íons de Hidrogênio , Estereoisomerismo
13.
J Zoo Wildl Med ; 51(2): 350-356, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32549564

RESUMO

Reptarenaviruses infect a variety of boid and pythonid snake species worldwide and have been shown to be the cause of inclusion body disease (IBD). Little is known about the correlations between virus infection and clinical disease, as well as the effects of viral infection on the immune system and the blood protein fractions. The goal of this study was to examine the differences in the plasma protein fractions in reptarenavirus reverse transcription polymerase chain reaction (RT-PCR)-negative and -positive tested snakes with and without clinical signs of disease. Blood from a total of 111 boa constrictors (Boa constrictor) was evaluated. Reverse transcription PCRs and H&E staining for inclusion bodies were carried out on each sample for the detection of reptarenavirus, and the plasma protein fractions were evaluated by capillary zone electrophoresis (CZE). Thirty four of the 111 evaluated snakes were positive by RT-PCR and 19 of the 34 showed clinical signs of disease. In comparison with IBD-negative healthy boa constrictors, the positive snakes with clinical signs had significantly lower albumin levels (P = 0.0052), lower A: G ratios (P = 0.0037), and lower α-globulin levels (P = 0.0073), while their γ-globulin levels were significantly higher (P = 0.0004). In the same comparison, clinically healthy arenavirus-positive boas showed only significantly lower α-globulin (P = 0.0124) and higher γ-globulin levels (P = 0.0394). The results of the present study indicate that reptarenavirus infection may influence plasma protein fractions in boa constrictors.


Assuntos
Infecções por Arenaviridae/virologia , Arenaviridae/fisiologia , Boidae/sangue , Eletroforese Capilar/veterinária , Animais , Valores de Referência
14.
Nucleic Acids Res ; 48(14): e80, 2020 08 20.
Artigo em Inglês | MEDLINE | ID: mdl-32496547

RESUMO

Small RNAs are important regulators of gene expression and are involved in human development and disease. Next generation sequencing (NGS) allows for scalable, genome-wide studies of small RNA; however, current methods are challenged by low sensitivity and high bias, limiting their ability to capture an accurate representation of the cellular small RNA population. Several studies have shown that this bias primarily arises during the ligation of single-strand adapters during library preparation, and that this ligation bias is magnified by 2'-O-methyl modifications (2'OMe) on the 3' terminal nucleotide. In this study, we developed a novel library preparation process using randomized splint ligation with a cleavable adapter, a design which resolves previous challenges associated with this ligation strategy. We show that a randomized splint ligation based workflow can reduce bias and increase the sensitivity of small RNA sequencing for a wide variety of small RNAs, including microRNA (miRNA) and tRNA fragments as well as 2'OMe modified RNA, including Piwi-interacting RNA and plant miRNA. Finally, we demonstrate that this workflow detects more differentially expressed miRNA between tumorous and matched normal tissues. Overall, this library preparation process allows for highly accurate small RNA sequencing and will enable studies of 2'OMe modified RNA with new levels of detail.


Assuntos
Biblioteca Gênica , Pequeno RNA não Traduzido/isolamento & purificação , Análise de Sequência de RNA/métodos , Eletroforese Capilar , Feminino , Humanos , Masculino , Metilação , MicroRNAs/química , MicroRNAs/genética , MicroRNAs/isolamento & purificação , Hibridização de Ácido Nucleico , Oligorribonucleotídeos/química , RNA Neoplásico/química , RNA Neoplásico/genética , RNA Neoplásico/isolamento & purificação , RNA de Plantas/química , RNA de Plantas/genética , RNA de Plantas/isolamento & purificação , Pequeno RNA não Traduzido/química , Pequeno RNA não Traduzido/genética , RNA de Transferência/química , RNA de Transferência/isolamento & purificação , Distribuição Aleatória , Sensibilidade e Especificidade , Alinhamento de Sequência
15.
J Chromatogr A ; 1621: 461075, 2020 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-32354558

RESUMO

The role of individual functional groups has been assessed with regard to surface charge and chromatographic retention. Coatings were prepared from various fragments of the chiral zwitterionic materials Chiralpak ZWIX(+) and ZWIX(-). The different chromatographic ligands allowed fine tuning of the surface charge. Chiralpak ZWIX phases showed strongly negative ζ-potentials over the entire pH-range. Zwitterionic congeners with quinuclidine and sulfonic acid moieties but lacking the quinolone ring in the ligand structure exhibited shifted ζ-potentials of around + 5 to 20 mV depending on the surrounding residues. Capillary electrophoretic mobilitiy measurements with the chromatographic ligands and molecular dynamics simulations were carried out to offer some explanation of these surface charge differences of the distinct zwitterionic stationary phases. The new mixed-mode phases were also chromatographically characterized by simple RP and HILIC tests. The results allowed their positioning within a large variety of different commercially available RP, HILIC and mixed-mode phases, which were evaluated as well, by multivariate data processing using principal component analysis. The new mixed-mode phases overall exhibit reasonable hydrophilicity-lipophilicity balance and enable retention of ionic compounds by additional ionic interactions through weak anion-exchange (WAX-type), strong cation-exchange (SCX-type) or both (RP/ZWIX-type). Hence, the new RP/ZWIX phases can be flexible tools for selectivity tuning in RP and HILIC separations.


Assuntos
Cromatografia por Troca Iônica/métodos , Ânions/química , Cátions/química , Eletroforese Capilar , Interações Hidrofóbicas e Hidrofílicas , Ligantes , Simulação de Dinâmica Molecular
16.
J Chromatogr A ; 1622: 461097, 2020 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-32381302

RESUMO

In this study, polymeric monoliths with gold nanoparticles (AuNP@monolith) were investigated as microcartridges for the analysis of protein biomarkers by on-line solid-phase extraction capillary electrophoresis-mass spectrometry (SPE-CE-MS). "Plug-and-play" microcartridges (7 mm) were prepared from a glycidyl methacrylate (GMA)-based monolithic capillary column (5 cm x 250 µm i.d.), which was modified with ammonia and subsequently functionalized with gold nanoparticles (AuNPs). The performance of these novel microcartridges was evaluated with human transthyretin (TTR), which is a protein related to different types of familial amyloidotic polyneuropathies (FAP). Protein retention depended on the isoelectric point of the protein (TTR pI~5.4) and elution was achieved with a basic phosphate solution. Under the optimized conditions, limits of detection (LODs) for TTR by AuNP@monolith-SPE-CE-MS were 50 times lower than by CE-MS (5 vs 250 mg•L-1, with an ion trap (IT) mass spectrometer). The sensitivity enhancement was similar compared to SPE-CE-MS using immunoaffinity (IA) microcartridges with intact antibodies against TTR. Linearity, repeatability in migration times and peak areas, reusability, reproducibility and application to serum samples were also evaluated.


Assuntos
Biomarcadores , Eletroforese Capilar , Ouro , Espectrometria de Massas , Nanopartículas Metálicas , Pré-Albumina , Extração em Fase Sólida , Biomarcadores/análise , Compostos de Epóxi/química , Ouro/química , Humanos , Limite de Detecção , Nanopartículas Metálicas/química , Metacrilatos/química , Polímeros/química , Pré-Albumina/análise , Reprodutibilidade dos Testes
17.
Food Chem ; 326: 126986, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-32407998

RESUMO

In the present work, a barcode-DNA analysis method is described for the detection of plant oil adulteration in milk and dairy products. The method relies on the fact that plant DNA should not be present in readily detectable amounts in a dairy product unless it contains undeclared plant material. Thus, a universal plant barcode is chosen as the target to be amplified from dairy samples. Accordingly, barcode PCR-CE (PCR-capillary electrophoresis) assays are described, which do not require preliminary information on the species source of the adulterant oil type. Two PCR-CE assays, one operating on the plastid trnL (UAA) intron and the other targeting its inner P6 loop in nested format, were shown to detect corn, soybean, rapeseed and sunflower oils in clarified butter, milk and yogurt. Both barcodes are robustly amplified with extremely conserved primers. While the intron provides the species discrimination ability, the P6 loop provides superior detection sensitivity.


Assuntos
DNA de Plantas/análise , Laticínios/análise , Eletroforese Capilar/métodos , Leite/química , Óleos Vegetais/química , Animais , Código de Barras de DNA Taxonômico , DNA de Plantas/genética , DNA de Plantas/metabolismo , Óleos Vegetais/metabolismo , Plastídeos/genética , Reação em Cadeia da Polimerase , Soja/genética , Iogurte/análise , Zea mays/genética
18.
J Vis Exp ; (159)2020 05 04.
Artigo em Inglês | MEDLINE | ID: mdl-32421003

RESUMO

Dyshomeostasis of iron metabolism is accounted in the pathophysiological framework of numerous diseases, including cancer and several neurodegenerative conditions. Excessive iron results in free redox-active Fe(II) and can cause devastating effects within the cell like oxidative stress (OS) and death by lipid peroxidation known as ferroptosis (FPT). Therefore, quantitative measurements of ferrous (Fe(II)) and ferric (Fe(III)) iron rather than total Fe-determination is the key for closer insight into these detrimental processes. Since Fe(II)/(III) determinations can be hampered by fast redox-state shifts and low concentrations in relevant samples, like cerebrospinal fluid (CSF), methods should be available that analyze quickly and provide low limits of quantification (LOQ). Capillary electrophoresis (CE) offers the advantage of fast Fe(II)/Fe(III) separation and works without a stationary phase, which could interfere with the redox balance or cause analyte sticking. CE combined with inductively coupled plasma mass spectrometry (ICP-MS) as a detector offers further improvement of detection sensitivity and selectivity. The presented method uses 20 mM HCl as a background electrolyte and a voltage of +25 kV. Peak shapes and concentration detection limits are improved by conductivity-pH-stacking. For reduction of 56[ArO]+, ICP-MS was operated in the dynamic reaction cell (DRC) mode with NH3 as a reaction gas. The method achieves a limit of detection (LOD) of 3 µg/L. Due to stacking, higher injection volumes were possible without hampering separation but improving LOD. Calibrations related to peak area were linear up to 150 µg/L. Measurement precision was 2.2% (Fe(III)) to 3.5% (Fe(II)). Migration time precision was <3% for both species, determined in 1:2 diluted lysates of human neuroblastoma (SH-SY5Y) cells. Recovery experiments with standard addition revealed accuracy of 97% Fe(III) and 105 % Fe(II). In real-life bio-samples like CSF, migration time can vary according to varying conductivity (i.e., salinity). Thus, peak identification is confirmed by standard addition.


Assuntos
Eletrólitos/metabolismo , Eletroforese Capilar/métodos , Ferro/análise , Espectrometria de Massas/métodos , Neuroblastoma/metabolismo , Humanos , Oxirredução , Células Tumorais Cultivadas
19.
Food Chem ; 321: 126705, 2020 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-32276144

RESUMO

Since seafood is susceptible to decomposition, additives may be used to maintain its quality. However, some additives may be improperly used to disguise spoilage, thus resulting in food fraud. Market growth demands faster and more reliable quality control tools that incorporate the most common additives in a single analysis. This study developed a rapid analytical method for the determination of citrate, phosphate and sulfite in seafood by capillary zone electrophoresis with indirect UV-Vis detection. Electrophoretic separation was achieved in less than 3.5 min. The background electrolyte consisted of 20 mmol L-1 of benzenesulfonic acid and 45 mmol L-1 of aminocaproic acid. After validation, the method was applied for 24 seafood real samples. Citrate was found in five samples. Four samples presented higher phosphate and sulfite concentrations than those permitted by Brazilian legislation. Good analytical performance indicates that the method is a viable alternative for food control in routine analysis.


Assuntos
Ácido Cítrico/análise , Eletroforese Capilar/métodos , Fosfatos/análise , Alimentos Marinhos/análise , Sulfitos/análise , Eletrólitos , Fatores de Tempo
20.
J Chromatogr A ; 1624: 461099, 2020 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-32327223

RESUMO

In this short communication, we report the use of a second-generation macrolide antibiotic, gamithromycin (Gam), as a novel chiral selector for enantioseparation in capillary electrophoresis (CE). A preliminary analysis of the experiment results shows that Gam is especially suitable for the separation of chiral primary amines. Factors influencing enantioseparations were systematically investigated including the composition of the background electrolyte (BGE), concentration of Gam, the type and proportion of organic solvents, applied voltage, etc. In particular, N-Methylformamide (NMF) was successfully used as a non-aqueous solvent for Gam, and shown to be extremely effective for the separation of primaquine (PMQ) and 1-aminoindan (AMI) when used alone or mixed with other commonly used non-aqueous solvents (e.g. methanol). To our knowledge this was also the first application of NMF as a non-aqueous solvent for antibiotic chiral selectors in CE. The best separations were obtained with 100 mM Tris, 125 mM H3BO3 and 80 mM Gam in methanol/NMF (25:75) solvent for PMQ and AMI, or 80-100 mM Gam in methanol for the other model analytes. Among the analytes, the resolution (Rs) of amlodipine (AML) reached up to 15.65, which is to our knowledge the highest value ever reported in CE studies for this compound (except for using molecularly imprinted polymers technique).


Assuntos
Antibacterianos/química , Eletroforese Capilar , Macrolídeos/química , Anlodipino/análise , Eletrólitos , Formamidas/química , Indanos/análise , Metanol/química , Primaquina/análise , Solventes/química , Estereoisomerismo
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