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1.
Braz Oral Res ; 33: e043, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31508727

RESUMO

Proteomic techniques have become popular in medicine and dentistry because of their widespread use in analyzing bodily fluids such as blood, saliva, urine, and gingival crevicular fluids as well as hard tissues such as enamel, dentine, and cementum. This review is a guide to proteomic techniques in general dentistry, summarizing techniques and their clinical application in understanding and diagnosing diseases and their use in identifying biomarkers of various diseases.


Assuntos
Proteoma , Proteômica/métodos , Saliva/química , Proteínas e Peptídeos Salivares/química , Biomarcadores/química , Eletroforese em Gel de Poliacrilamida/métodos , Humanos , Espectrometria de Massas/métodos , Neoplasias Bucais/diagnóstico , Síndrome de Sjogren/diagnóstico
2.
J Agric Food Chem ; 67(41): 11542-11552, 2019 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-31538781

RESUMO

Two field trials were conducted to investigate the influence of fungicide and fertilization management on the potato tubers' metabolome (Solanum tuberosum L.). Thereby, fungicides and conventional fertilizers were varied in terms of quantities, number and date of applications, physical state, and product composition. Following a water-methanol-based extraction, samples were analyzed using an UPLC-IMS-QToF and multivariate data analysis. Fungicide application led to significant changes in the tubers' metabolome. Flavonoids were increasingly expressed as a natural response to impending fungal or viral infections in an untreated group, while the phytoalexin rishitinol was highly abundant in groups with fungicide application. In contrast to fungicides, the application of conventional fertilizers did not cause significant alterations in the tubers' compound composition. Consequently, the impact of fungicide application could be rated as more important than the fertilization-derived influence, which might be because of a gentler adaption to fertilization than to the acute stress of fungicide applications.


Assuntos
Produção Agrícola/métodos , Fertilizantes/análise , Fungicidas Industriais/farmacologia , Espectrometria de Massas/métodos , Tubérculos/química , Solanum tuberosum/efeitos dos fármacos , Cromatografia Líquida de Alta Pressão , Metaboloma , Tubérculos/efeitos dos fármacos , Tubérculos/crescimento & desenvolvimento , Tubérculos/metabolismo , Solanum tuberosum/química , Solanum tuberosum/crescimento & desenvolvimento , Solanum tuberosum/metabolismo
3.
J Agric Food Chem ; 67(39): 10984-10993, 2019 Oct 02.
Artigo em Inglês | MEDLINE | ID: mdl-31525294

RESUMO

The objective of the present study was to reveal the effects of four types of nitrogen sources (soymeal, yeast extract, KNO3, and ammonium tartrate) on the lipid metabolism of the oleaginous fungus Mortierella alpina using untargeted lipidomics, targeted fatty acid, and reverse transcription quantitative polymerase chain reaction (RT-qPCR) analysis. Our results showed clear differences in the contents and compositions of lipids between four types of nitrogen sources. Soymeal and ammonium tartrate supplementation favored the accumulation of triglycerides with arachidonic acid (ARA) and C16-18 fatty acids, respectively. These results were further validated by our targeted fatty acid analysis. RT-qPCR analysis of related genes in M. alpina between the four nitrogen source conditions found that soymeal supplementation dramatically increased the expression of GPAT, ELOVL, and Δ12/Δ6 desaturase. Our findings provided new insights into the regulation of lipid biosynthesis in M. alpina and potential avenues for genetic manipulation and highlighted the importance of an optimal nitrogen source for ARA-rich oil production.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Lipídeos/biossíntese , Lipídeos/química , Espectrometria de Massas/métodos , Mortierella/metabolismo , Nitrogênio/metabolismo , Ácidos Graxos Dessaturases/genética , Ácidos Graxos Dessaturases/metabolismo , Ácidos Graxos/biossíntese , Ácidos Graxos/química , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Mortierella/química , Mortierella/enzimologia , Mortierella/genética
4.
Chemosphere ; 235: 1107-1115, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31561301

RESUMO

Two analytical techniques - online Gas Chromatography coupled with Flame Ionization Detector (often used method for VOCs monitoring) versus Selected Ion Flow Tube coupled with Mass Spectrometry (a more recent technique based on direct mass spectrometry) - were compared in association to an ozone-based gas treatment. Selecting aldehydes as the representative VOCs, their concentrations were monitored during ozonation experiments by both techniques in parallel. Contradictory results were obtained in the presence of ozone. Aldehydes were up to 90% removed due to a reaction with ozone according to GC/FID analysis, whereas with SIFT/MS, aldehydes concentration remained at the same level during the experiments regardless of the ozone presence. In addition, it was demonstrated that the apparent aldehydes removal was affected by GC injector temperature, varying from 90% (when it was at 250 °C) to 60% (at 100 °C). Meanwhile, even when the ozonation reactor was heated to 100 °C, no aldehydes conversion was evidenced by SIFT/MS, suggesting that the GC injector temperature was not the only interference-causing parameter. The ozone-aldehyde reaction is probably catalyzed by some material of GC injector and/or column. An ozone-GC interference was therefore confirmed, making unsuitable the use of GC/FID with silicone stationary phase to monitor aldehydes in presence of high concentrations of ozone (at least 50 ppmv). On the other hand, SIFT/MS was validated as a reliable technique, which can be employed in order to measure VOCs concentrations in ozonation processes.


Assuntos
Aldeídos/análise , Ionização de Chama/métodos , Cromatografia Gasosa-Espectrometria de Massas/métodos , Ozônio/química , Aldeídos/química , Espectrometria de Massas/métodos , Reprodutibilidade dos Testes , Compostos Orgânicos Voláteis/análise , Compostos Orgânicos Voláteis/química
5.
Environ Monit Assess ; 191(8): 525, 2019 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-31363866

RESUMO

Arsenic contamination in marine environments is a serious issue because some arsenicals are very toxic, increasing the health risks associated with the consumption of marine products. This study describes the development of an improved rapid method for the quantification of arsenic species, including arsenite (AsIII), arsenate (AsV), arsenocholine (AsC), arsenobetaine (AsB), dimethylarsinic acid (DMA), and monomethyl arsonic acid (MMA), in seaweed, sediment, and seawater samples using high-performance liquid chromatography/inductively coupled plasma-mass spectrometry (HPLC/ICP-MS). ICP-MS based on dynamic reaction cells was used to eliminate spectral interference. Ammonium nitrate- and phosphate-based eluents were used as the mobile phases for HPLC analysis, leading to shorter overall retention time (6 min) and improved peak separation. Arsenicals were extracted with a 1% HNO3 solution that required no clean-up process and exhibited reasonable sensitivity and peak resolution. The optimized method was verified by applying it to hijiki seaweed certified reference material (CRM, NMIJ 7405-a) and to spiked blank samples of sediment and seawater. The proposed method measured the concentration of AsV in the CRM as 9.6 ± 0.6 µg/kg dry weight (dw), which is close to the certified concentration (10.1 ± 0.5 µg/kg dw). The recovery of the six arsenicals was 87-113% for the sediment and 99-101% for the seawater. In the analysis of real samples, AsV was the most abundant arsenical in hijiki and gulfweed, whereas AsB was dominant in other seaweed species. The two inorganic arsenicals (AsIII and AsV) and AsV were the most dominant in the sediment and seawater samples, respectively.


Assuntos
Arsenicais/análise , Cromatografia Líquida de Alta Pressão/métodos , Monitoramento Ambiental/métodos , Espectrometria de Massas/métodos , Poluentes Químicos da Água/análise , Monitoramento Ambiental/instrumentação , Sedimentos Geológicos/química , República da Coreia , Água do Mar/química , Alga Marinha/química
6.
J Mass Spectrom ; 54(9): 729-737, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31432563

RESUMO

Fentanyl and related psychoactive substances are at the forefront of the opioid overdose crisis, for which a complete solution is not immediately obvious. Drug testing for harm reduction may be an effective approach to both reduce overdoses and importantly, engage people who use drugs (PWUD) with the medical system. Paper spray mass spectrometry (PS-MS) is an ambient ionization strategy that is uniquely suited to address this complicated analytical task. This perspectives article presents the merits of PS-MS, with a focus upon the current state of its use as a candidate drug checking strategy for harm reduction. PS-MS is inherently sensitive and selective, with detection limits in the picogram range. It requires small drug samples (~1 mg) for quantitative drug testing, critical to encourage pre-consumption measurements by PWUD in the context of a harm reduction strategy. Calibrations obtained in surrogate drug matrices containing highly concentrated primary drugs demonstrate comparable sensitivities, a wide calibration range, and minimal matrix effects. PS-MS can be interfaced with high-resolution MS for non-targeted analysis, allowing the identification of novel psychoactive substances as they appear in street drugs. Individual quantitative PS-MS measurements for drug testing can be done in 1 minute or less, resulting in high sample throughput. Significant advancement in mass spectrometer miniaturization and mobilization has concomitant benefits for direct, on-site drug checking, such as reduced cost, simplified maintenance and ease of use by less skilled operators. While PS-MS technology continues to rapidly advance, it is our opinion that PS-MS can be utilized as an effective tool for harm reduction in the opioid overdose crisis.


Assuntos
Overdose de Drogas/prevenção & controle , Fentanila/análogos & derivados , Fentanila/análise , Espectrometria de Massas/instrumentação , Espectrometria de Massas/métodos , Psicotrópicos/análise , Drogas Ilícitas/análise , Redução do Dano , Ensaios de Triagem em Larga Escala/instrumentação , Ensaios de Triagem em Larga Escala/métodos , Humanos , Limite de Detecção , Miniaturização , Sensibilidade e Especificidade , Detecção do Abuso de Substâncias/métodos , Fatores de Tempo
7.
J Agric Food Chem ; 67(36): 10174-10184, 2019 Sep 11.
Artigo em Inglês | MEDLINE | ID: mdl-31418563

RESUMO

The progress of lipid oxidation in foods is evaluated by measuring the peroxides and their scission products. However, hydrogen abstraction-independent pathways are not considered by commonly applied methods despite the known reactivity of epoxides toward biomolecules. Herein, a novel liquid chromatography tandem-mass spectrometry method was developed to detect hydroperoxidized and epoxidized triacylglycerols (TAGs) without derivatization or hydrolyzation of food samples. Epoxidized TAGs could be detected in refined canola oil at concentrations of 96.8 ± 2.08 µM, while only 5.77 ± 0.04 µM hydroperoxidized TAGs could be determined. In contrast to canola oil, margarine was more resistant to lipid oxidation since generation of epoxidized TAGs could only be marginally enhanced from 21.7 ± 0.48 to 28.8 ± 0.64 µM in margarine after treatment at 180 °C for 60 min, as also reflected by a peroxide value of 0.80 ± 0.00 mequiv O2/kg, which remained unchanged. The new method allows the assessment of food safety by the simultaneous measurement of hydroperoxidized and epoxidized TAGs without hydrolysis and laborious sample preparation.


Assuntos
Cromatografia Líquida/métodos , Margarina/análise , Espectrometria de Massas/métodos , Óleo de Brassica napus/química , Triglicerídeos/química , Compostos de Epóxi/química , Peróxido de Hidrogênio/química , Oxirredução
8.
Plant Sci ; 286: 49-56, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31300141

RESUMO

Progress in the functional biochemical analysis of plant glycosyltransferases (GTs) has been slow because plant GTs are generally membrane proteins, operate as part of larger, multimeric complexes, and utilize a vast complexity of substrate acceptors. Therefore, the field would benefit from development of adequate high throughput expression as well as product detection and characterization techniques. Here we review current approaches to tackle such obstacles and suggest a new path forward: nucleic acid programmable protein arrays (NAPPA) with liquid sample desorption ionization (LS-DESI-MS) mass spectrometry. NAPPA utilizes in vitro transcription and translation to produce epitope-tagged fusion proteins from cloned GT cDNAs. LS-DESI is a soft ionization technique that allows rapid and sensitive MS-based product characterization in situ. Coupling both approaches provides the opportunity to examine individual GT functions as well as protein-protein interactions. Furthermore, advances in automated oligosaccharide synthesis and lipid nanodisc technology should allow testing of plant GT activity in presence of numerous substrate acceptors and lipid environments in a high throughput fashion. Thus, NAPPA-DESI-MS has great potential to make headway in biochemical characterization of the large number of plant GTs.


Assuntos
Parede Celular/química , Ensaios de Triagem em Larga Escala/métodos , Plantas/química , Polissacarídeos/biossíntese , Análise Serial de Proteínas/métodos , Glicosiltransferases/análise , Espectrometria de Massas/métodos , Proteínas de Plantas/análise , Plantas/enzimologia
9.
J Agric Food Chem ; 67(31): 8425-8430, 2019 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-31322874

RESUMO

In recent years, non-targeted methods have been a popular "buzz" phrase in food fraud detection. Using analytical instrumentation techniques, non-targeted methods have been developed and applied in many food and agricultural situations. However, confusion and misstatements remain regarding how the methods are used. This perspective will discuss the definitions related to non-targeted testing, the procedure of developing and validating methods, the techniques and data analysis, and opportunities and challenges regarding the use of this class of analytical methods. The perspective seeks to provide readers with the latest information regarding recent advances in the use of non-targeted methods.


Assuntos
Análise de Alimentos/métodos , Contaminação de Alimentos/análise , Cromatografia Líquida/métodos , Eletroforese Capilar/métodos , Análise de Alimentos/instrumentação , Humanos , Espectroscopia de Ressonância Magnética/métodos , Espectrometria de Massas/métodos
10.
J Chromatogr A ; 1602: 386-396, 2019 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-31285057

RESUMO

A comprehensive Collision Cross Section (CCS) library was obtained via Travelling Wave Ion Guide mobility measurements through direct infusion (DI). The library consists of CCS and Mass Spectral (MS) data in negative and positive ElectroSpray Ionisation (ESI) mode for 463 and 479 endogenous metabolites, respectively. For both ionisation modes combined, TWCCSN2 data were obtained for 542 non-redundant metabolites. These data were acquired on two different ion mobility enabled orthogonal acceleration QToF MS systems in two different laboratories, with the majority of the resulting TWCCSN2 values (from detected compounds) found to be within 1% of one another. Validation of these results against two independent, external TWCCSN2 data sources and predicted TWCCSN2 values indicated to be within 1-2% of these other values. The same metabolites were then analysed using a rapid reversed-phase ultra (high) performance liquid chromatographic (U(H)PLC) separation combined with IM and MS (IM-MS) thus providing retention time (tr), m/z and TWCCSN2 values (with the latter compared with the DI-IM-MS data). Analytes for which TWCCSN2 values were obtained by U(H)PLC-IM-MS showed good agreement with the results obtained from DI-IM-MS. The repeatability of the TWCCSN2 values obtained for these metabolites on the different ion mobility QToF systems, using either DI or LC, encouraged the further evaluation of the U(H)PLC-IM-MS approach via the analysis of samples of rat urine, from control and methotrexate-treated animals, in order to assess the potential of the approach for metabolite identification and profiling in metabolic phenotyping studies. Based on the database derived from the standards 63 metabolites were identified in rat urine, using positive ESI, based on the combination of tr, TWCCSN2 and MS data.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Espectrometria de Mobilidade Iônica/métodos , Espectrometria de Massas/métodos , Metaboloma , Urina/química , Aminas/análise , Animais , Calibragem , Aprendizado de Máquina , Ratos , Padrões de Referência
11.
Jpn J Ophthalmol ; 63(4): 328-336, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31273564

RESUMO

PURPOSE: To report the clinical manifestations, identification, antimicrobial susceptibilities, and treatment outcomes of ocular infections caused by Moraxella species. STUDY DESIGN: Retrospective study. PATIENTS AND METHODS: The medical records of all patients treated at the Departments of Ophthalmology of the Ogaki Municipal Hospital and the Gifu University Graduate School of Medicine for ocular infections caused by Moraxella species between January 2011 and June 2017 were examined. The stored Moraxella species isolated from ocular samples were identified by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS), molecular identification, and the biochemical properties. RESULTS: Sixteen eyes of 16 patients were treated for Moraxella ocular infections. The patients' median age was 72 years. A predisposing systemic or ocular condition was identified in 15 of the patients. Nine of the patients developed keratitis; four, conjunctivitis; and three, blebitis. M lacunata (6 eyes), M catarrhalis (6), M nonliquefaciens (3), and M osloensis (1) were identified by MALDI-TOF MS. All isolates were sensitive to levofloxacin, tobramycin, ceftazidime, ceftriaxone, and cefazolin. Twelve patients with keratitis or blebitis were treated with various topical antimicrobial combinations, and systemic antibiotics were used in 10 of the 12 patients. The mean time for the complete closure of the epithelial defects with keratitis was 24 days. The visual outcomes after treatment were favorable except in 1 keratitis patient who underwent enucleation. CONCLUSIONS: The use of duo-therapy with a combination of fluoroquinolone and cefmenoxime should be considered in cases nonresponsive to monotherapy, such as keratitis and bleb-associated infections. MALDI-TOF MS is useful for the identification of Moraxella to the species level.


Assuntos
Conjuntivite/diagnóstico , Infecções Oculares Bacterianas/diagnóstico , Ceratite/diagnóstico , Espectrometria de Massas/métodos , Moraxella/isolamento & purificação , Infecções por Moraxellaceae/diagnóstico , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , Túnica Conjuntiva/diagnóstico por imagem , Túnica Conjuntiva/microbiologia , Conjuntivite/microbiologia , Córnea/diagnóstico por imagem , Córnea/microbiologia , Infecções Oculares Bacterianas/microbiologia , Feminino , Humanos , Lactente , Ceratite/microbiologia , Masculino , Pessoa de Meia-Idade , Infecções por Moraxellaceae/microbiologia , Reprodutibilidade dos Testes , Estudos Retrospectivos , Adulto Jovem
12.
Food Chem ; 299: 125146, 2019 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-31302427

RESUMO

Matrix effects in complex tea matrices remains a great challenge to rapid quantitative analysis of multi-residue pesticides by analysis of mass spectrometry. Herein, a mixed-mode polymer cationic exchange based dispersive solid-phase extraction (DSPE) procedure was established to eliminate matrix effects of tea for a rapid target alkaline multi-residue pesticides analysis. One-step DSPE procedure can eliminate matrix interferences from the tea extract without additional dilution or tedious cleanup operations. Liquid chromatography-high resolution mass spectrometry using pre-column dilution injection mode was used as the detection technique, while eliminating solvent effects of target analytes and improving the detection sensitivity. Based on this effective analytical method, the results of absolute matrix effects were within 0.77-1.08 for quantitation of the 68 alkaline pesticides, and superior relative matrix effects were also achieved with RSD values below 9.8%. Finally, this method was validated and applied to the alkaline pesticides analysis of the 123 tea samples.


Assuntos
Cromatografia Líquida/métodos , Espectrometria de Massas/métodos , Resíduos de Praguicidas/análise , Extração em Fase Sólida/métodos , Chá/química , Cafeína/isolamento & purificação , Análise de Alimentos/métodos , Contaminação de Alimentos/análise , Resíduos de Praguicidas/química , Polifenóis/isolamento & purificação , Reprodutibilidade dos Testes
13.
Food Chem ; 299: 125166, 2019 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-31323443

RESUMO

Dynamic high-pressure microfluidization (DHPM) pretreatment and glycation with lactose were employed to modify α-Lactalbumin (α-LA) with respect to the IgE/IgG binding capacities. No significant difference on incorporation ratio value of glycated α-LA was observed with and without DHPM pretreatment. However, IgE/IgG binding capacities of α-LA were decreased after glycation and DHPM pretreatment promoted the reduction. The lowest IgE/IgG binding capacities of glycated α-LA were obtained by DHPM pretreatment at 110 MPa. Native α-LA was mainly glycated at K62, K94, K98, whereas glycation sites and degree of substitution per peptide (DSP) were added after DHPM treatment. Therefore, the reduced IgE/IgG binding capacities of α-LA was attributed to the characteristics of glycated sites, including the amount, location, and DSP values. Interestingly, K98 played the most important role in decreasing IgE/IgG binding capacities of α-LA. The study revealed that glycation combined with DHPM was a promising way to decrease the allergenicity of proteins.


Assuntos
Hipersensibilidade Alimentar/imunologia , Imunoglobulina E/metabolismo , Imunoglobulina G/metabolismo , Lactalbumina/metabolismo , Alérgenos/química , Animais , Bovinos , Ensaio de Imunoadsorção Enzimática , Indústria de Processamento de Alimentos/métodos , Humanos , Lactalbumina/química , Lactalbumina/imunologia , Lactose/química , Lisina/metabolismo , Espectrometria de Massas/métodos , Pressão , Coelhos
14.
Anal Bioanal Chem ; 411(23): 6091-6100, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31289897

RESUMO

Two 600-bp DNA solutions (DNA600-G and DNA600-T) were developed as certified reference material, NMIJ CRM 6205-a, for the validation of DNA quantification methods. Both DNA600-G and DNA600-T are ideal as "spike-in control" because these materials have artificial nucleic acid sequences. The certified values were determined as the mass concentration of total DNA (whole DNA materials in sample solution regardless of sequence) at 25 °C by formic acid hydrolysis/liquid chromatography-isotope dilution mass spectrometry (LC-IDMS) and inductively coupled plasma-mass spectrometry (ICP-MS) based on the amount of phosphorus. DNAs were synthesized, and plasmids including the synthesized DNAs were cloned into Escherichia coli DH5α. The amplified plasmids were digested with a restriction enzyme and highly purified. Then, the purified DNAs were diluted with water to approximately 1 ng/µL. By using the CRM-validated methods in fields where DNA quantification is required, the reliability of DNA quantification could be improved. Graphical abstract.


Assuntos
DNA/análise , Espectrometria de Massas/métodos , Sequência de Bases , Cromatografia Líquida de Alta Pressão/métodos , Cromatografia Líquida de Alta Pressão/normas , Cromatografia Líquida/métodos , Cromatografia Líquida/normas , DNA/genética , Formiatos/química , Hidrólise , Espectrometria de Massas/normas , Plasmídeos/análise , Plasmídeos/genética , Reação em Cadeia da Polimerase/métodos , Reação em Cadeia da Polimerase/normas , Padrões de Referência
15.
Environ Pollut ; 253: 439-448, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31325889

RESUMO

Ambient submicron particles (PM1) exert significant impacts on visibility degradation during severe pollution episodes of urban China. The U.S. IMPROVE algorithms are widely used for assessing the extinction effect of atmospheric aerosols, but only suitable for fine particulate matter. A proper algorithm for PM1 extinction estimation is lacking and becomes urgent, especially after the online measurement of PM1 species is routine by aerosol mass spectrometers. Here we conducted three-month in-situ measurements to explore mass scattering efficiencies (MSE) of PM1 major species at a supersite of eastern China. Results indicated that MSEs of ammonium sulfate and nitrate increase quickly and then keep stable with the mass accumulation, while those of organic matter keep at ∼5.5 m2/g but with a large vibration in the whole mass range. The algorithm for reconstructing PM1 dry scattering coefficient was derived from the integral of the variation patterns for the three PM1 species. The algorithm was then validated and compared with other empirical algorithms through separate field measurements. Good correlations between the reconstructed and measured dry scattering coefficient were observed with R square higher than 0.9 and slope of 1.01-1.05, indicating that the reconstructed algorithm can predict the dry scattering coefficient well based on PM1 chemical composition measurements in urban China. Our study is expected to provide observed insights on the variation of MSE in the wide mass range especially in the high region, as well as accurate formulas for ambient PM1 dry scattering apportionment.


Assuntos
Poluentes Atmosféricos/análise , Poluição do Ar/estatística & dados numéricos , Monitoramento Ambiental/métodos , Aerossóis/análise , Algoritmos , China , Espectrometria de Massas/métodos , Nitratos/análise , Óxidos de Nitrogênio , Tamanho da Partícula , Material Particulado/análise
16.
Food Chem ; 301: 125137, 2019 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-31362191

RESUMO

Multi-isotope and multi-elemental analyses were performed on 600 red wine samples imported into China from 7 different countries and compared with Chinese wine. Carbon and oxygen isotopes and 16 elements were used to determine origin traceability. Our goal was to build a classification tool using data modeling that can verify the geographic origin of wines imported into China. Multivariate analyses of the isotopic and elemental data revealed that it is possible to determine the geographical origin for most imported wines with a high level of confidence (>90%). The results show that Artificial Neural Network method had a high discrimination accuracy and is more suitable than Discrimination Analysis and Random Forest methods when it comes to classifying wine origin on a global scale. In conclusion, stable isotope and trace element analyses followed by multivariate processing of the data is a fast and efficient technique suitable for global wine traceability.


Assuntos
Análise de Alimentos/métodos , Vinho/análise , Isótopos de Carbono/análise , China , Análise Discriminante , Espectrometria de Massas/métodos , Modelos Estatísticos , Análise Multivariada , Isótopos de Oxigênio/análise , Oligoelementos/análise
17.
Crit Rev Oncol Hematol ; 141: 153-162, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31302407

RESUMO

Failure of systemic cancer treatment can be, at least in part, due to the drug not being delivered to the tumour at sufficiently high concentration and/or sufficiently homogeneous distribution; this is termed as "pharmacokinetic drug resistance". To understand whether a drug is being adequately delivered to the tumour, "precision pharmacology" techniques are needed. Mass spectrometry imaging (MSI) is a relatively new and complex technique that allows imaging of drug distribution within tissues. In this review we address the applicability of MSI to the study of cancer drug distribution from the bench to the bedside. We address: (i) the role of MSI in pre-clinical studies to characterize anti-cancer drug distribution within the body and the tumour, (ii) the application of MSI in pre-clinical studies to define optimal drug dose or schedule, combinations or new drug delivery systems, and finally (iii) the emerging role of MSI in clinical research.


Assuntos
Antineoplásicos/administração & dosagem , Antineoplásicos/farmacocinética , Resistencia a Medicamentos Antineoplásicos , Espectrometria de Massas/métodos , Neoplasias/diagnóstico , Neoplasias/tratamento farmacológico , Disponibilidade Biológica , Diagnóstico por Imagem/métodos , Relação Dose-Resposta a Droga , Esquema de Medicação , Sistemas de Liberação de Medicamentos , Monitoramento de Medicamentos/métodos , Humanos , Neoplasias/metabolismo , Medicina de Precisão/métodos , Distribuição Tecidual
18.
Food Chem ; 299: 125105, 2019 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-31295636

RESUMO

Within the cocoa market (Theobroma cacao L.), quality and prices are often determined by geographical origin, making traceability indispensable. Therefore, to investigate possibilities of tracing by analytical methods, 48 carefully selected cocoa samples from 20 countries have been profiled using a combination of stable isotope-ratio mass spectrometry (IRMS) and proton nuclear magnetic resonance (1H NMR). Chemometric analysis of combined data sets from both, stable isotope data (δ13C, δ15N, δ18O, δ2H, %C, %N, %O, %H) and 1H NMR fingerprints, achieved good separation with increased classification rates compared to classification with data of the isolated methods. IRMS contributed primarily to discrimination between countries, while 1H NMR significantly contributed to separation of varieties, but also the regions within individual countries. This study thus demonstrates that combination of two analytical methods is an effective tool to enhance both, accuracy and precision, in authenticity testing of cocoa.


Assuntos
Cacau/química , Deutério/análise , Análise de Alimentos/métodos , Espectrometria de Massas/métodos , Espectroscopia de Prótons por Ressonância Magnética/métodos , Isótopos de Carbono/análise , Análise Multivariada , Isótopos de Nitrogênio/análise , Isótopos de Oxigênio/análise
19.
Anal Chim Acta ; 1078: 1-7, 2019 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-31358206

RESUMO

The novel laser ablation inductively coupled plasma mass spectrometry methodology for the rapid screening of elemental impurities in solid pharmaceutical samples with the daily dose less than 2.0 g has been developed in accordance with requirements of established USP <232/233> chapters and ICH-Q3D guideline. The LA-ICP-MS methodology covering the determination of Cd, Pb, As, Hg, Co, V, Ni, Tl, Au, Pd, Ir, Os, Rh, Ru, Se, Ag, Pt was successfully validated in terms of linearity, limit of quantification, accuracy, precision, intermediate precision, specificity and range. Moreover, the presented 'in-house' matrix-matched standards preparation methodology helps to overcome crucial analytical problem connected with unavailability of commercial certified matrix-matched reference material suitable for the direct elemental impurities analysis in various kinds of solid pharmaceutical products. A two step homogeneity study of prepared matrix-matched calibration standards is also reported to investigate the homogeneity of distribution of elemental impurities and internal standards across the pressed pellet. The validated LA-ICP-MS method was applied on analysis of several types of solid pharmaceutical samples (active pharmaceutical ingredients, excipients, placebo and final drug products). The proposed method allowed the accurate, precise and fast screening of elemental impurities without necessity of time and labour consuming solutions preparation and thus it can be used in routine practice as an alternative to conventional ICP-MS or ICP-OES for the rapid quality control of different stages of pharmaceutical production.


Assuntos
Espectrometria de Massas/métodos , Metais Pesados/análise , Preparações Farmacêuticas/análise , Calibragem , Contaminação de Medicamentos , Espectrometria de Massas/normas , Padrões de Referência , Selênio/análise
20.
Food Chem ; 298: 125003, 2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31260957

RESUMO

The oral breakdown, sensory properties, and volatile release during mastication of white bread were investigated. The results of correlation analysis for white bread's physical properties and it's oral physiological parameters during chewing have elucidated that bread's physical properties determined the oral processing behavior. During chewing of white bread, 15 dominant ions with regularly changing patterns were monitored by proton transfer reaction-mass spectrometry (PTR-MS). These dominant ions derived from 32 volatile compounds were further confirmed by pure standards. Partial least squares regression (PLSR) analysis was used to explore the positive correlations between the sensory analysis and the dominant aroma compounds. Results have shown that 9 aroma compounds were predicted as the potent odorants contributing to the changes in aroma profiles. Finally, 3-hydroxy-2-butanone, 2-methyl-1-propanol, and heptanoic acid were confirmed as the key aroma compounds contributing to the changes in aroma profiles of white bread before and after chewing.


Assuntos
Pão , Mastigação , Odorantes/análise , Compostos Orgânicos Voláteis/análise , Acetoína/análise , Adulto , Pão/análise , Butanóis/análise , Feminino , Cromatografia Gasosa-Espectrometria de Massas/métodos , Cromatografia Gasosa-Espectrometria de Massas/estatística & dados numéricos , Ácidos Heptanoicos/análise , Humanos , Análise dos Mínimos Quadrados , Masculino , Espectrometria de Massas/métodos , Espectrometria de Massas/estatística & dados numéricos , Saliva/química , Microextração em Fase Sólida/métodos , Paladar , Triticum/química
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