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1.
J Chromatogr A ; 1621: 461049, 2020 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-32252986

RESUMO

Herein, we report three-dimensional paper chromatography (3D-PC) as a micro-chromatographic platform. The method was based on applying the origami microfluidic device for separation, coupled by colorimetric methods for simultaneous determination. The microfluidic device fabrication was a facile printing approach. Two azo food dyes, Tartrazine (E102) and Indigo carmine (E132), were selected as a model analyte, while carbonate-bicarbonate buffer was used as the mobile phase. Our micro-chromatographic device is associated with two big advantages including needing very small volume of mobile phase ( ~12 µL) and ultrafast separation time (~35 s). Under the optimal conditions, the method provided acceptable linear ranges of 0. 0 g L1-18.0 g L1 (R2 = 0.997) for E102 and 0.070 g L1-10.0 g L1 for E132 and the limits of detection (3σ/slope) were evaluated as 0.620 and 0.060 g L1, respectively. The proposed method was successfully applied in the separation and quantification of these dyes in commercial food products such as jelly, candy, and four kinds of drink samples without any sample preparation prior to analysis. The mean recovery values for the real sample analysis were in the range of 100.14%-102.38% for E132 and E102 respectively. The inter-device relative standard deviations were in the ranges of 1.5%-11.8%. In total, our chromatographic µPAD is small (1.0 cm × 1.0 cm × 0.5 cm), portable, inexpensive, no need of specialized user, requires low volumes of sample (0.5 µL), and can perform separation using 12 µL of aqueous mobile phase in very short time.


Assuntos
Cromatografia em Papel/instrumentação , Cromatografia em Papel/métodos , Corantes de Alimentos/análise , Índigo Carmim/análise , Dispositivos Lab-On-A-Chip , Tartrazina/análise , Colorimetria
2.
Anal Chim Acta ; 1097: 120-126, 2020 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-31910951

RESUMO

In this study, we developed a point-of-care assay platform with simultaneous detection and self-calibration capabilities for multiple targets based on a microfluidic paper-based analytical device (µPAD). This system is easily manufactured using a wax printing method on chromatographic paper. The design pattern consists of a zone of detection and a calibrant zone for controlled loading using wax barriers with different thicknesses. We showed the utility and applicability of this approach by a proof-of-concept study for two clinically important markers: glucose and lactate. With the naked eye, the results could be fully distinguished and recorded to evaluate the analytical performance with a flatbed scanner. The detection limits of glucose and lactate were 0.3125 mM and 0.2975 mM, respectively, and simultaneous detection was possible from a small sample (0.4 µL) with high sensitivity. Furthermore, this device has a self-calibration function, which minimizes the influence of environmental conditions (i.e., ambient light intensity, temperature, humidity, and pressure). Therefore, the developed multiplex paper-based device is promising for clinical multianalyte point-of-care testing since it is easy to manufacture, cost-effective, user-friendly, and highly sensitive.


Assuntos
Cromatografia em Papel , Glucose/análise , Ácido Láctico/análise , Técnicas Analíticas Microfluídicas , Biomarcadores/análise , Calibragem , Cor , Colorimetria , Modelos Moleculares
3.
Anal Chim Acta ; 1078: 16-23, 2019 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-31358214

RESUMO

The adulteration of herbal medicines by dexamethasone or prednisolone is regarded as a serious problem in many communities. Herein, a novel platform for the separation and quantification of both target steroids in herbal medicines based on electrochemical paper-based analytical devices (ePADs) has been created. The ePAD was composed of Whatman SG81 chromatography paper, 3D-printed devices and a commercial screen-printed electrode. Whatman SG81 silica-coated paper was used for the separation of dexamethasone and prednisolone based on the difference in their partition coefficients during the flow of the mobile phase. The optimal mobile phase was composed of 60% ethyl acetate in cyclohexane and required 7 min for separation. The separated steroids on the paper were then quantified by electrochemical detection using differential pulse voltammetry, in which the 3D-printed devices facilitated the measurement. Analytical detection ranges of 10-500 µg mL-1 were obtained for both dexamethasone and prednisolone (r2 = 0.988 and 0.994, respectively). The limits of detection for dexamethasone and prednisolone were 3.59 and 11.98 µg mL-1, respectively, whereas the limits of quantification were 6.00 and 20.02 µg mL-1, respectively. The amounts of both target steroids derived from real herbal medicine samples determined by the proposed method were comparable to those obtained with assays using standard high-performance liquid chromatography. In addition, a simple evaporation step can be used to increase the concentration of the samples before analysis. These ePADs are simple, low-cost, rapid, and very promising for on-site quantitative detection.


Assuntos
Cromatografia em Papel/métodos , Dexametasona/análise , Técnicas Eletroquímicas/métodos , Preparações Farmacêuticas/análise , Preparações de Plantas/análise , Prednisolona/análise , Carbono/química , Cromatografia em Papel/instrumentação , Contaminação de Medicamentos , Técnicas Eletroquímicas/instrumentação , Eletrodos , Limite de Detecção , Papel , Impressão Tridimensional
4.
Dalton Trans ; 47(25): 8346-8355, 2018 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-29896594

RESUMO

In this work, we present a facile preparation of a paper-based glucose assay for rapid, sensitive, and quantitative measurement of glucose in blood plasma and urine. Two copper phosphorescent complexes [Cu(2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline)(2,6-dimethylphenylisocyanide)2][B(C6H3(CF3)2)4] (Cu1) and [Cu(2,9-dimethyl-1,10-phenanthroline)(2,6-dimethylphenylisocyanide)2][B(C6H3(CF3)2)4] (Cu2) and a new silver congener [Ag(P3)CNAg(P3)][B(C6H3(CF3)2)4] (Ag3) (P3 = PPh2C6H4-PPh-C6H4PPh2 [bis(o-diphenylphosphinophenyl)phenylphosphine]) have been synthesized and their oxygen sensing abilities were investigated. The dimetallic phosphine-based Ag3 complex, having a high oxygen sensing ability, was employed as an efficient signal transducer in enzymatic reactions to recognize blood plasma glucose and urine glucose, which provided a wide linear response for a concentration range between 1.0 and 35 mM and a rapid response, with a limit of detection (LOD) of 0.09 mM for glucose. In practical application, this Ag3 paper-based device offers great analytical reliability and accuracy upon monitoring glucose concentrations in blood plasma.


Assuntos
Técnicas Biossensoriais , Glicemia/análise , Complexos de Coordenação/química , Glicosúria/urina , Prata/química , Cromatografia em Papel , Complexos de Coordenação/síntese química , Cobre/química , Humanos , Limite de Detecção , Luminescência , Oxigênio/química , Fenantrolinas/química , Fosfinas/química
5.
Adv Healthc Mater ; 7(14): e1800104, 2018 07.
Artigo em Inglês | MEDLINE | ID: mdl-29766658

RESUMO

The design and fabrication of reconfigurable, modular paperfluidics driven by a prefabricated reusable block library, asynchronous modular paperfluidic linear instrument-free (Ampli) block, are reported. The blocks are inspired by the plug-and-play modularity of electronic breadboards that lower prototyping barriers in circuit design. The resulting biochemical breadboard is a paperfluidic construction set that can be functionalized with chemical, biological, and electrical elements. Ampli blocks can form standard paperfluidic devices without any external instrumentation. Furthermore, their modular nature enhances fluidics in ways that fixed devices cannot. The blocks' ability to start, stop, modify, and reverse reaction flows, reagents, and rates in real time is demonstrated. These enhancements allow users to increase colorimetric signals, fine tune reaction times, and counter check multiplexed diagnostics for false positives or negatives. The modular construction demonstrates that field-ready, distributed fabrication of paper analytical systems can be standardized without requiring the "black box" of craft and technique inherent in paper-based systems. Ampli assembly and point-of-care redesign extends the usability of paper analytical systems and invites user-driven prototyping beyond the lab setting demonstrating "Design for Hack" in diagnostics.


Assuntos
Técnicas Analíticas Microfluídicas/métodos , Cromatografia em Papel/métodos , Sensibilidade e Especificidade
6.
J Biosci Bioeng ; 126(3): 397-403, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-29673986

RESUMO

Although nucleic acid amplification test (NAT) is widely used for pathogen detection, rapid NAT systems that do not require special and expensive instruments must be developed in order to enable point of care (POC)-NATs, which contribute to early initiation of treatment. As a POC-NAT system, Kaneka DNA chromatography chip (KDCC), developed using DNA tag-bound primer through modified substance, was shown to be suitable for POC testing, due to the rapid detection time, simple procedures, and low manufacturing costs. However, owing to some modifications in primer, the detection performance and amplification speed were shown to be reduced when using KDCC, counteracting the increased speed of detection. To solve these issues and improve the speed of this NAT system, we investigated a better modification substance for KDCC. Here, azobenzene-modified primers were shown to have the highest amplification speed and detection performance in KDCC, of all modifications tested in this study, showing 10-100-fold lower detection limit but maintaining the same reaction time. Additionally, rapid herpes simplex virus detection system with azobenzene modified primers was developed. We believed that this breakthrough will contribute toward enabling greater utilization of POC-NATs for medical care, especially in developing countries and clinics.


Assuntos
Compostos Azo/química , Cromatografia em Papel/métodos , Técnicas de Amplificação de Ácido Nucleico/métodos , Análise de Sequência com Séries de Oligonucleotídeos , Oligonucleotídeos/química , Cromatografia em Papel/instrumentação , Primers do DNA/química , DNA Bacteriano/química , Humanos , Limite de Detecção , Desnaturação de Ácido Nucleico , Análise de Sequência com Séries de Oligonucleotídeos/instrumentação , Análise de Sequência com Séries de Oligonucleotídeos/métodos , Sistemas Automatizados de Assistência Junto ao Leito
7.
ACS Sens ; 3(4): 852-857, 2018 04 27.
Artigo em Inglês | MEDLINE | ID: mdl-29652135

RESUMO

Surface-enhanced Raman scattering (SERS) is a powerful analytical tool which enables the detection and identification of analytes adsorbed on nanostructured noble metals. However, SERS analysis of complex mixtures can be challenging due to spectral overlap and interference. In this report, we demonstrate a method to simplify the identification of mixed-analyte samples by coupling SERS detection with chromatographic separation on a nanoplasmonic paper substrate. This "nanopaper" substrate is a silver coated glass microfiber filter paper which possesses large SERS enhancement and can serve as a stationary phase in paper chromatography. Nanopaper is easily synthesized using the silver mirror reaction, making it a highly accessible technology. Nanopaper was successfully used as a combined paper chromatography-SERS (PC-SERS) substrate in the separation and identification of mixed organic dyes. It was further employed to separate and identify lycopene and ß-carotene in commercial food products, demonstrating the versatility and utility of nanopaper in the identification of complex mixtures.


Assuntos
Cromatografia em Papel , Nanopartículas Metálicas/química , Papel , Prata/química , Análise Espectral Raman , Filtração , Nanopartículas Metálicas/economia , Tamanho da Partícula , Propriedades de Superfície
8.
J Mass Spectrom ; 53(1): 58-64, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-28960779

RESUMO

The ability to rapidly identify and quantitate, over a wide range of concentrations, anthocyanins in food and therapeutic products is important to ensuring their presence at medicinally significant levels. Sensitive, yet mild, analysis conditions are required given their susceptibility to degradation and transformation. Paper spray ionization has been used to detect and quantify the levels of anthocyanin levels in extracts of fresh and dried elderberries, and elderberry stems, as well as 3 commercially available nutraceutical formulations. The component cyanidin glucosides, including cyanidin-3-sambubioside, cyanidin-3-glucoside, cyanidin-3,5-diglucoside, cyanidin-3-sambubioside-5-glucoside, and the aglycone cyanidin, were readily detected in a range of sources. Quantitation was achieved by establishing a calibration plot from dilutions of a stock solution of cyanidin-3,5-diglucoside containing malvidin-3,5-diglucoside as an internal standard at a fixed concentration. The same standard was used to quantify the anthocyanin content in the fruit and nutraceutical formulations. Wide 5-fold variations in anthocyanin concentration were detected in the nutraceutical formulations from different suppliers ranging from 1050 to 5430 mg/100 g. These concentrations compared with 500 to 2370 mg/100 g measured in the dried stems and fruit, respectively.


Assuntos
Antocianinas/análise , Suplementos Nutricionais/análise , Sambucus/química , Antocianinas/química , Cromatografia em Papel , Frutas/química , Humanos , Espectrometria de Massas , Extratos Vegetais/análise , Extratos Vegetais/química
9.
Toxicol Mech Methods ; 28(4): 243-251, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-29185369

RESUMO

After the cigarette is extinguished, many toxic compounds remain in the environment and accumulate in the air or on surfaces. This exposure is termed thirdhand smoke (THS) and its risks are poorly known. The aim of the study was to evaluate the cellular effects of THS from smokers' homes. Papers were placed in nine smoker's home and three nonsmoker's homes. An area equivalent to the paper size was cleaned with a cotton wipe. A549, Hep-2 and 3T3 cells were exposed to THS for 24 h and cellular functions were assessed by MTT, neutral red (NR) reuptake and trypan blue exclusion assays. High levels of nicotine were found in samples from smokers' homes. Cellular proliferation was similar in almost all samples after THS exposure. Few changes in the cellular functions were observed, mainly higher mitochondrial activity, in paper samples. We are able to detect markers of THS collected from smokers' homes, but a clear evidence of cellular toxicity cannot be demonstrated by the present assays. This is the first study to evaluate the cellular effects of THS samples collected from smokers' homes.


Assuntos
Poluição do Ar em Ambientes Fechados/efeitos adversos , Monitoramento Ambiental/métodos , Habitação , Poluição por Fumaça de Tabaco/efeitos adversos , Células 3T3 , Células A549 , Poluição do Ar em Ambientes Fechados/análise , Animais , Brasil , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Cromatografia em Papel , Cromatografia Gasosa-Espectrometria de Massas , Habitação/normas , Humanos , Camundongos , Poluição por Fumaça de Tabaco/análise
10.
Sci Rep ; 7: 43905, 2017 03 02.
Artigo em Inglês | MEDLINE | ID: mdl-28252113

RESUMO

Distinguishing a specific biomarker from a biofluid sample containing a large variety of proteins often requires the selective preconcentration of that particular biomarker to a detectable level for analysis. Low-cost, paper-based device is an emerging opportunity in diagnostics. In the present study, we report a novel Zinc oxide nanorods functionalized paper platform for the preconcentration of Myoglobin, a cardiac biomarker. Zinc oxide nanorods were grown on a Whatman filter paper no. 1 via the standard hydrothermal route. The growth of Zinc oxide nanorods on paper was confirmed by a combination of techniques consisting of X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS,) scanning electron microscopy (SEM), and energy dispersive spectroscopy (EDX) analysis. The Zinc oxide nanorods modified Whatman filter paper (ZnO-NRs/WFP) was further tested for use as a protein preconcentrator. Paper-based ELISA was performed for determination of pre-concentration of cardiac marker protein Myoglobin using the new ZnO-NRs/WFP platform. The ZnO-NRs/WFP could efficiently capture the biomarker even from a very dilute solution (Myoglobin < 50 nM). Our ELISA results show a threefold enhancement in protein capture with ZnO-NRs/WFP compared to unmodified Whatman filter paper, allowing accurate protein analysis and showing the diagnostic concept.


Assuntos
Cromatografia em Papel/métodos , Mioglobina/isolamento & purificação , Nanotubos , Papel , Óxido de Zinco/metabolismo , Humanos
11.
Curr Pharm Des ; 23(2): 231-241, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-27774906

RESUMO

BACKGROUND: This review aims to present the relevant background information and current research status in concentration of polyphenols using membrane technologies. The potential implementation of membrane separation to bioactive compounds like soluble phenolics from aqueous and organic solvent solutions is gaining increasing interest in the recent years. This review does not pretend to cover the abundant published literature on the subject, but to be representative for the observed tendencies in membrane processes applications for concentration of polyphenols derived from natural products. The first part of the article includes general information regarding the polyphenols and the traditional methods for their separation (such as: thin layer chromatography; paper chromatography; gas chromatography; high performance liquid chromatography; capillary electrophoresis), while the second part presents a review of different membrane processes applied for concentration of polyphenols. Three main sources for such implementations are discussed: (1) aqueous or organic solvent extracts from plant material, (2) fruits, and (3) recovery of polyphenols from industrial waste liquids. A diversity of membrane processes are considered in a large scope of implementations ranging from lab-scale studies to pilot and semiindustrial scale operations. CONCLUSION: Membrane technology is an excellent candidate to make a paradigm shift in biological active compounds fractionation/separation processes. Presented results clearly demonstrate that membrane processes are of great advantages over traditionally used methods; however, characterization of separated polyphenols has to be improved. Most of citied authors concentrated their investigation only on the total amount of polyphenols determination. Exhaustive studies including: antioxidant activities, retention index, total soluble solids, or volume reduction factor, have been only carried out by a few authors.


Assuntos
Fracionamento Químico/métodos , Membranas Artificiais , Polifenóis/isolamento & purificação , Cromatografia Gasosa , Cromatografia Líquida de Alta Pressão , Cromatografia em Papel , Cromatografia em Camada Delgada , Eletroforese Capilar
12.
Ceska Slov Farm ; 65(2): 70-7, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27356596

RESUMO

UNLABELLED: This article presents the results of testing of phenolic compounds (flavonoids, isoflavonoids, xanthones, phenolcarboxylic acids, tannins, coumarins, etc.) in the rhizomes of four Iris species (Iris sibirica L., Iris pseudacorus L., Iris imbricatа Lindl., Iris hungarica Waldst. et Kit.). With the use of paper and thin-layer chromatography, fifteen phenolic compounds were identified: gallic, coumaric, cinnamic, chlorogenic, neochlorogenic, ferulic, caffeic acids; kaempferol, quercetin, hispidulin, daidzein, genistein, formononetin, mangiferin and isomangiferin. Quantitative contents of flavonoids (1.2-3.7%), hydroxycinnamic acids (0.6-6.5%), γ-pyrones (0.01-0.8%), tannins (6-14%), isoflavonoids (1-2%), polyphenolic compounds (up to 3%) in the rhizomes of the Iris species were determined. Chosen plants belong to natural flora and have been often cultivated. However, this phytochemical analysis for the main groups of the biologically active substances shows a perspective use of the Iris species in medicine. KEY WORDS: Iris species Iridaceae phenolic compounds chromatography qualitative analysis quantitative contents.


Assuntos
Iris (Planta)/química , Fenóis/análise , Rizoma/química , Ácidos Carboxílicos/análise , Cromatografia em Papel , Cromatografia em Camada Delgada , Cumarínicos/análise , Flavonoides/análise , Taninos/análise , Xantonas/análise
13.
Anal Sci ; 32(3): 355-9, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26960618

RESUMO

A detection method of gold nanoparticles in chromatography paper has been developed for a simple, cost-effective and reliable quantitation of immunochromatographic strip test. The time courses of the solution resistance in chromatography paper with the gold nanoparticles solution are electrochemically measured by chrono-impedimetry. The dependence of the solution resistance on the concentration of gold nanoparticles has been successfully observed. The main factor to increase the solution resistance may be obstruction of the ion transport due to the presence of gold nanoparticles. The existence of gold nanoparticles with 1.92 × 10(9) particles/mL in an indistinctly-colored chromatography paper is also identified by a solution resistance measurement. This indicates that the solution resistance assay has the potential to lower the detection limit of the conventional qualitative assay.


Assuntos
Cromatografia de Afinidade/métodos , Cromatografia em Papel/métodos , Coloides/análise , Impedância Elétrica , Ouro/análise , Nanopartículas Metálicas/química , Cromatografia de Afinidade/instrumentação , Cromatografia em Papel/instrumentação , Coloides/química , Desenho de Equipamento , Ouro/química , Nanopartículas Metálicas/análise , Tamanho da Partícula , Fitas Reagentes
14.
J Chromatogr B Analyt Technol Biomed Life Sci ; 1015-1016: 142-149, 2016 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-26922000

RESUMO

Paper spray (PS), as a new ambient ionization method, has been applied for direct qualitative and quantitative analysis. The high sensitivity and minimum internal energy (low spray voltage) with optimized paper spray conditions is a significant request for real application in POCT. In this study, a simple and efficient ambient ionization method is developed by spraying from a mesoporous graphene foams (MGFs)-modified paper surface. The good electrical conductivity of MGFs results in obvious spray voltage decrease. Meanwhile, the MGFs-paper substrate has a well improvement in separation and elution efficiency ascribing to ultrahigh specific surface area and π-π electrostatic stacking property of graphene. In combination a commercial triple quadrupole mass spectrometer, the paper spray is successfully used for analysis of amphetamine in saliva. The linear dynamic ranges expand 10 fold in comparison with unmodified chromatography papers and the low limit of quantitation (LOQ) is as low as 1 pg/mL. A small sample volume (0.5 µL) could be analyzed immediately after spotting, without any pretreatment. The performance of this method was demonstrated for application in fast point-of-care mass spectrometry.


Assuntos
Cromatografia em Papel/instrumentação , Cromatografia em Papel/métodos , Monitoramento de Medicamentos/métodos , Grafite/química , Anfetamina/análise , Desenho de Equipamento , Humanos , Modelos Lineares , Saliva/química , Sensibilidade e Especificidade , Espectrometria de Massas por Ionização por Electrospray/métodos
15.
Eur J Clin Microbiol Infect Dis ; 35(3): 353-61, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26796551

RESUMO

To detect Salmonella more efficiently and isolate strains more easily, a novel and simple detection method that uses an enrichment assay and two chromogenic reactions on a chromatography membrane was developed. Grade 3 chromatography paper is used as functionalized solid phase support (SPS), which contains specially optimized medium. One reaction for screening is based on the sulfate-reducing capacity of Salmonella. Hydrogen sulfide (H2S) generated by Salmonella reacts with ammonium ferric citrate to produce black colored ferrous sulfide. Another reaction is based on Salmonella C8 esterase that is unique for Enterobacteriaceae except Serratia and interacts with 4-methylumbelliferyl caprylate (MUCAP) to produce fluorescent umbelliferone, which is visible under ultraviolet light. A very low detection limit (10(1) CFU ml(-1)) for Salmonella was achieved on the background of 10(5) CFU ml(-1) Escherichia coli. More importantly, testing with more than 1,000 anal samples indicated that our method has a high positive detection rate and is relatively low cost, compared with the traditional culture-based method. It took only 1 day for the preliminary screening and 2 days to efficiently isolate the Salmonella cells, indicating that the new assay is specific, rapid, and simple for Salmonella detection. In contrast to the traditional culture-based method, this method can be easily used to screen and isolate targeted strains with the naked eye. The results of quantitative and comparative experiments showed that the visual detection technique is an efficient alternative method for the screening of Salmonella spp. in many applications of large-sized samples related to public health surveillance.


Assuntos
Técnicas Bacteriológicas , Cromatografia em Papel/métodos , Salmonella/isolamento & purificação , Humanos , Sulfeto de Hidrogênio/metabolismo , Himecromona/análogos & derivados , Himecromona/química , Salmonella/classificação , Salmonella/metabolismo , Infecções por Salmonella/diagnóstico , Infecções por Salmonella/microbiologia , Sensibilidade e Especificidade
16.
Braz J Med Biol Res ; 48(10): 902-7, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26445333

RESUMO

Knowledge of the radiochemical purity of radiopharmaceuticals is mandatory and can be evaluated by several methods and techniques. Planar chromatography is the technique normally employed in nuclear medicine since it is simple, rapid and usually of low cost. There is no standard system for the chromatographic technique, but price, separation efficiency and short time for execution must be considered. We have studied an alternative system using common chromatographic stationary phase and alcohol or alcohol:chloroform mixtures as the mobile phase, using the lipophilic radiopharmaceutical [(99m)Tc(MIBI)6]⁺ as a model. Whatman 1 modified phase paper and absolute ethanol, Whatman 1 paper and methanol:chloroform (25:75), Whatman 3MM paper and ethanol:chloroform (25:75), and the more expensive ITLC-SG and 1-propanol:chloroform (10:90) were suitable systems for the direct determination of radiochemical purity of [(99m)Tc(MIBI)6]⁺ since impurities such as (99m)Tc-reduced-hydrolyzed (RH), (99m)TcO(4)(-) and [(99m)Tc(cysteine)2]⁻ complex were completely separated from the radiopharmaceutical, which moved toward the front of chromatographic systems while impurities were retained at the origin. The time required for analysis was 4 to 15 min, which is appropriate for nuclear medicine routines.


Assuntos
Cromatografia em Papel/métodos , Cromatografia em Camada Delgada/métodos , Compostos Radiofarmacêuticos/análise , Pertecnetato Tc 99m de Sódio/análise , Álcoois , Clorofórmio , Cromatografia/economia , Cromatografia/métodos , Cromatografia em Papel/economia , Cromatografia em Camada Delgada/economia , Controle de Qualidade , Compostos Radiofarmacêuticos/classificação
17.
Braz. j. med. biol. res ; 48(10): 902-907, Oct. 2015. tab, ilus
Artigo em Inglês | LILACS | ID: lil-761597

RESUMO

Knowledge of the radiochemical purity of radiopharmaceuticals is mandatory and can be evaluated by several methods and techniques. Planar chromatography is the technique normally employed in nuclear medicine since it is simple, rapid and usually of low cost. There is no standard system for the chromatographic technique, but price, separation efficiency and short time for execution must be considered. We have studied an alternative system using common chromatographic stationary phase and alcohol or alcohol:chloroform mixtures as the mobile phase, using the lipophilic radiopharmaceutical [99mTc(MIBI)6]+ as a model. Whatman 1 modified phase paper and absolute ethanol, Whatman 1 paper and methanol:chloroform (25:75), Whatman 3MM paper and ethanol:chloroform (25:75), and the more expensive ITLC-SG and 1-propanol:chloroform (10:90) were suitable systems for the direct determination of radiochemical purity of [99mTc(MIBI)6]+ since impurities such as99mTc-reduced-hydrolyzed (RH),99mTcO4- and [99mTc(cysteine)2]-complex were completely separated from the radiopharmaceutical, which moved toward the front of chromatographic systems while impurities were retained at the origin. The time required for analysis was 4 to 15 min, which is appropriate for nuclear medicine routines.


Assuntos
Cromatografia em Papel/métodos , Cromatografia em Camada Delgada/métodos , Compostos Radiofarmacêuticos/análise , /análise , Álcoois , Clorofórmio , Cromatografia em Papel/economia , Cromatografia em Camada Delgada/economia , Cromatografia/economia , Cromatografia/métodos , Controle de Qualidade , Compostos Radiofarmacêuticos/classificação
18.
J Zhejiang Univ Sci B ; 16(8): 672-9, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26238542

RESUMO

Traditional methods for detecting lactoperoxidase (LP) are complex and time-consuming, so a test strip was made based on the enzymatic reaction principle to enable quick and convenient detection of LP in raw milk. In this study 0.1 mol/L citric acid (CA)/0.2 mol/L disodium hydrogen phosphate (NaP) buffer solution (pH 5.0), 22 mmol/L 3,3',5,5'-tetramethylbenzidine (TMB), 0.6 mmol/L hydrogen peroxide (H2O2), and 0.5% Tween-20 or 0.3% cetyltrimethyl ammonium bromide (CTAB) were optimal for preparing a quick, sensitive, and accurate LP test strip. The coefficient of variation (CV) of the estimated LP concentrations ranged from 2.47% to 6.72% and the minimum LP concentration detected by the test strip was 1-2 mg/L. Estimates of active LP in sixteen raw milk samples obtained using the test strip or the TMB method showed a good correlation (r=0.9776). So the test strip provides a quick, convenient, and accurate method for detecting the LP concentration of raw milk.


Assuntos
Equipamentos Descartáveis , Análise de Alimentos/instrumentação , Contaminação de Alimentos/análise , Lactoperoxidase/análise , Leite/química , Fitas Reagentes , Animais , Cromatografia em Papel/instrumentação , Compostos Cromogênicos/química , Desenho de Equipamento , Análise de Falha de Equipamento , Pasteurização , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
19.
Ann Bot ; 116(2): 225-36, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26113633

RESUMO

BACKGROUND AND AIMS: During evolution, plants have acquired and/or lost diverse sugar residues as cell-wall constituents. Of particular interest are primordial cell-wall features that existed, and in some cases abruptly changed, during the momentous step whereby land-plants arose from charophytic algal ancestors. METHODS: Polysaccharides were extracted from four charophyte orders [Chlorokybales (Chlorokybus atmophyticus), Klebsormidiales (Klebsormidium fluitans, K. subtile), Charales (Chara vulgaris, Nitella flexilis), Coleochaetales (Coleochaete scutata)] and an early-diverging land-plant (Anthoceros agrestis). 'Pectins' and 'hemicelluloses', operationally defined as extractable in oxalate (100 °C) and 6 m NaOH (37 °C), respectively, were acid- or Driselase-hydrolysed, and the monosaccharides analysed chromatographically. One unusual monosaccharide, 'U', was characterized by (1)H/(13)C-nuclear magnetic resonance spectroscopy and also enzymically. KEY RESULTS: 'U' was identified as 3-O-methyl-D-galactose (3-MeGal). All pectins, except in Klebsormidium, contained acid- and Driselase-releasable galacturonate, suggesting homogalacturonan. All pectins, without exception, released rhamnose and galactose on acid hydrolysis; however, only in 'higher' charophytes (Charales, Coleochaetales) and Anthoceros were these sugars also efficiently released by Driselase, suggesting rhamnogalacturonan-I. Pectins of 'higher' charophytes, especially Chara, contained little arabinose, instead possessing 3-MeGal. Anthoceros hemicelluloses were rich in glucose, xylose, galactose and arabinose (suggesting xyloglucan and arabinoxylan), none of which was consistently present in charophyte hemicelluloses. CONCLUSIONS: Homogalacturonan is an ancient streptophyte feature, albeit secondarily lost in Klebsormidium. When conquering the land, the first embryophytes already possessed rhamnogalacturonan-I. In contrast, charophyte and land-plant hemicelluloses differ substantially, indicating major changes during terrestrialization. The presence of 3-MeGal in charophytes and lycophytes but not in the 'intervening' bryophytes confirms that cell-wall chemistry changed drastically between major phylogenetic grades.


Assuntos
Carofíceas/química , Embriófitas/química , Metilgalactosídeos/análise , Pectinas/análise , Polissacarídeos/análise , Fracionamento Celular , Parede Celular/química , Cromatografia Líquida de Alta Pressão , Cromatografia em Papel , Cromatografia em Camada Delgada , Proteínas Fúngicas/metabolismo , Glicosídeo Hidrolases/metabolismo , Monossacarídeos/análise , Espectroscopia de Prótons por Ressonância Magnética , Padrões de Referência , Estereoisomerismo
20.
Anal Chim Acta ; 858: 82-90, 2015 Feb 09.
Artigo em Inglês | MEDLINE | ID: mdl-25597806

RESUMO

This paper presents a simple and low-cost method for patterning poly(dimethylsiloxane) (PDMS) barriers in porous support such as paper for the construction of flexible microfluidic paper-based analytical devices (µPADs). The fabrication method consisted of contact-printing a solution of PDMS and hexane (10:1.5 w/w) onto chromatographic paper using custom-designed rubber stamps containing the patterns of µPADs. After penetrating the paper (∼30 s), the PDMS is cured to form hydrophobic barriers. Under optimized conditions, hydrophobic barriers and hydrophilic channels with dimensions down to 949±88 µm and 771±90 µm (n=5), respectively, were obtained. This resolution is well-suitable for most applications in analytical chemistry. Chemical compatibility studies revealed that the PDMS barriers were able to contain some organic solvents, including acetonitrile and methanol, and aqueous solutions of some surfactants. This find is particularly interesting given that acetonitrile and methanol are the most used solvents in chromatographic separations, non-aqueous capillary electrophoresis and electroanalysis, as well as aqueous solutions of surfactants are suitable mediums for cell lyses assays. The utility of the technique was evaluated in the fabrication of paper-based electrochemical devices (PEDs) with pencil-drawn electrodes for experiments in static cyclic voltammetry and flow injection analysis (FIA) with amperometric detection, in both aqueous and organic mediums.


Assuntos
Cromatografia em Papel , Dimetilpolisiloxanos/química , Técnicas Analíticas Microfluídicas , Papel , Impressão , Borracha , Acetaminofen/análise , Cromatografia em Papel/instrumentação , Cromatografia em Papel/métodos , Eletrodos , Desenho de Equipamento , Análise de Injeção de Fluxo , Hexanos/química , Interações Hidrofóbicas e Hidrofílicas , Técnicas Analíticas Microfluídicas/instrumentação , Técnicas Analíticas Microfluídicas/métodos , Solventes/química
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