Encyclopedia of Analytical Chemistry最新文献

{"title":"Ricin Analysis","authors":"Suzanne R. Kalb, J. R. Barr","doi":"10.1002/9780470027318.a9388.pub2","DOIUrl":"https://doi.org/10.1002/9780470027318.a9388.pub2","url":null,"abstract":"","PeriodicalId":119970,"journal":{"name":"Encyclopedia of Analytical Chemistry","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127113198","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Gas in Scattering Media Absorption Spectroscopy","authors":"S. Svanberg","doi":"10.1002/9780470027318.A9325","DOIUrl":"https://doi.org/10.1002/9780470027318.A9325","url":null,"abstract":"Gas in scattering media absorption spectroscopy (GASMAS) is a new variety of tunable diode laser spectroscopy (TDLS). It combines concepts from atmospheric trace-gas monitoring with those pertinent to biological tissue optics. The former field deals with high-resolution spectroscopy in nonscattering media, whereas the latter area is characterized by broad absorption structures in strongly scattering media. GASMAS provides novel applications in, e.g. the material science and biophotonics fields. The absorptive imprints of free gases inside pores or cavities in surrounding solid or liquid matter are typically many orders of magnitude narrower than those of the host material, a fact that is critically utilized. The gas signals are detected in the weak, multiply scattered light emerging from the illuminated sample. Wavelength-modulation and phase-sensitive detection techniques are employed, typically in connection with single-mode CW lasers. Any gas with useful absorption at wavelengths where the host material does not absorb strongly can be detected. For biological tissue, containing liquid water and blood, this limits the useful region to the “tissue optical window” –650–1400 nm – where, however, the interesting gases oxygen and water vapor absorb at around 760 and 950 nm, respectively. This limitation does not pertain to other materials, particularly not to those that do not contain liquid water. GASMAS experiments, which relate to basic physics, include studies of nanoporous ceramics, where wall collisions influence the line shape and provide information on pore-size distribution. A small piece of strongly scattering ceramic can serve as an alignment-free multipass cell with effective path length hundreds of times longer than the physical dimension. Porosity and gas transport studies in construction materials such as polystyrene foams, wood, ceramics, and paper are examples of applications in the material science field. The technique is further very powerful for studying gas in the human body and products that humans eat, such as packaged foods, fruits, and pharmaceutical preparations. A key aspect of food packaging is to prevent oxygen to influence the food. Frequently, modified atmospheres with nitrogen or carbon dioxide as filling gases are used. Applications include monitoring the performance of packaging machines and measurements of the product on the shelf. Porosity in pharmaceutical tablets is important to determine, as it has bearing on controlled release. Following initial work on healthy volunteers, a clinical trial concerning human sinus cavities has been performed. Gas filling and composition can be used as a diagnostic tool in connection with sinusitis, a very common disorder, also related to the problem with heavy overprescription of antibiotics and associated growing bacterial resistance. Following realistic phantom studies, it was shown that it is possible to detect gas in the lungs and intestines of a newborn baby, which could be","PeriodicalId":119970,"journal":{"name":"Encyclopedia of Analytical Chemistry","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133821326","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Electroanalytical Methods Based on Hybrid Nanomaterials","authors":"P. Yáñez‐Sedeño, R. Villalonga, J. Pingarrón","doi":"10.1002/9780470027318.A9394","DOIUrl":"https://doi.org/10.1002/9780470027318.A9394","url":null,"abstract":"Hybrid nanomaterials, defined as an intentional combination of at least a nanomaterial with one or more materials, at an atomic or a nanometer level of mixture, complementing each other to have new or improved functions and properties which component materials did not possess, provide new possibilities for electroanalytical methods The relevant functional properties of nanomaterials can be tuned, in an unimaginable manner, by rational combination with other materials. This fact opens an exciting door for sensor and biosensor technology, which is well supported by the advances in other areas such as surface science, organic and inorganic synthesis, polymer and biomolecular chemistry, and nanotechnology. This article provides a general sight state of the art on the use of nanosized hybrid materials as transduction, amplification, and labeling elements for the establishment of original electrochemical methods of analysis, exemplified with some of the most relevant research published in the past 5 years. The article is divided into two main categories: (i) electrochemical sensors based on hybrid nanomaterials of inorganic–organic, inorganic–inorganic, and organic–organic composition hybrid nanomaterials; (ii) electrochemical biosensors making use of metal nanostructures, carbon nanomaterials, metal and nonmetal oxide nanomaterials, and soft-nanomaterials hybrids. \u0000 \u0000 \u0000Keywords: \u0000 \u0000hybrid nanomaterials; \u0000functionalized surfaces; \u0000electrochemical sensors; \u0000electrochemical biosensors","PeriodicalId":119970,"journal":{"name":"Encyclopedia of Analytical Chemistry","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125281599","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Supramolecular Solvents in the Analytical Process","authors":"Encarnación Romera García, A. Gómez","doi":"10.1002/9780470027318.a9396.pub2","DOIUrl":"https://doi.org/10.1002/9780470027318.a9396.pub2","url":null,"abstract":"","PeriodicalId":119970,"journal":{"name":"Encyclopedia of Analytical Chemistry","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117225885","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Nuclear Magnetic Resonance as Analytical Tool for Crude Plant Extracts","authors":"A. Bilia","doi":"10.1002/9780470027318.A9913","DOIUrl":"https://doi.org/10.1002/9780470027318.A9913","url":null,"abstract":"Authentication, quality control, and stability testing of crude plant extracts are generally achieved and well established through HPLC, HPTLC, and capillary GC, using specific detectors such as UV–vis, RI, and coupled systems (MS), which allow the qualitative and quantitative determination of the composition of the markers or active substances. The major disadvantages of these conventional methods lie in the time consuming for the development of simple and rapid chromatographic separation and for the preparation of samples before measurements. In addition, these techniques are not able to reveal unknown plant metabolites that can contribute to the biological activity. \u0000 \u0000 \u0000 \u0000NMR spectroscopy is nondestructive, selective, and capable of simultaneous detection of a great number of constituents. The identification by NMR provides on both major and minor components, with no restrictions relating to volatility, polarity, or the presence of specific chromophores. Finally, the method can be applied without knowledge of the composition of the sample. NMR spectra contain information about the identity of the molecules in the extracts and are useful to quantify the constituents. NMR spectroscopy coupled with chemometric tools has been successfully applied to the characterization of various herbs and plant extracts for quality control, authentication, determining geographical origin, and detecting adulteration of herbal drugs and extracts. \u0000 \u0000 \u0000Keywords: \u0000 \u0000plant extracts; \u00001D- and 2D-NMR analyses; \u0000DOSY NMR; \u0000quantitative NMR; \u0000NMR and multivariate statistics (or chemometrics); \u0000authentication; \u0000quality control and stability testing","PeriodicalId":119970,"journal":{"name":"Encyclopedia of Analytical Chemistry","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125156955","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Automatic Continuous Online Monitoring and Control of Polymerization Reactions and Related Methods","authors":"W. Reed","doi":"10.1002/9780470027318.a9288.pub2","DOIUrl":"https://doi.org/10.1002/9780470027318.a9288.pub2","url":null,"abstract":"","PeriodicalId":119970,"journal":{"name":"Encyclopedia of Analytical Chemistry","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130615072","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Supercritical Fluid Extraction in Plant Analysis","authors":"S. M. Pourmortazavi, M. Rahimi‐Nasrabadi, Somayeh Mirsadeghi","doi":"10.1002/9780470027318.A9903","DOIUrl":"https://doi.org/10.1002/9780470027318.A9903","url":null,"abstract":"This chapter presents comprehensive information on applications and developments of supercritical fluid extraction (SFE) technique in plant oils and herbal volatile components analysis. Supercritical carbon dioxide (SC-CO2) is widely used for extraction and isolation of volatile and essential oil of plants. SFE possesses valuable advantages in extraction of various analytes, especially nonpolar compounds, from plant matrices. Meanwhile, some modifications such as the usage of modifiers make this technique applicable for the extraction of polar targets as well. SFE in herbal field is used for the extraction of a wide range of analytes including food, agricultural agents, pharmaceuticals, cosmetics, and pesticides. This chapter aims to review, from plant oil analysis standpoint, recent advances in the use of SC-CO2 for the extraction and separation of herbal analytes. In addition, it presents a critical appraisal about the advantages and disadvantages of SFE technique in comparison with traditional extraction methods, that is, Soxhlet, hydrodistillation (HD), and head space extraction. The abilities, advantages, shortcomings, and prospects of SFE for isolation and extraction of volatile components and essential oil of plant materials are also discussed. \u0000 \u0000 \u0000Keywords: \u0000 \u0000supercritical fluid extraction; \u0000supercritical carbon dioxide; \u0000plant oil extraction; \u0000volatile components analysis; \u0000supercritical fluid","PeriodicalId":119970,"journal":{"name":"Encyclopedia of Analytical Chemistry","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124928825","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Characterization of Protein Oligomers by Multi‐Angle Light Scattering","authors":"Mai Shamir, Hadar Amartely, M. Lebendiker, A. Friedler","doi":"10.1002/9780470027318.a9545","DOIUrl":"https://doi.org/10.1002/9780470027318.a9545","url":null,"abstract":"","PeriodicalId":119970,"journal":{"name":"Encyclopedia of Analytical Chemistry","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125350335","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Atomic Force Microscopy Methods forDNAAnalysis","authors":"Y. Lyubchenko","doi":"10.1002/9780470027318.a9258.pub2","DOIUrl":"https://doi.org/10.1002/9780470027318.a9258.pub2","url":null,"abstract":"","PeriodicalId":119970,"journal":{"name":"Encyclopedia of Analytical Chemistry","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122556532","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Fundamentals and Advances of Orbitrap Mass Spectrometry","authors":"M. Scigelová, A. Makarov","doi":"10.1002/9780470027318.A9309","DOIUrl":"https://doi.org/10.1002/9780470027318.A9309","url":null,"abstract":"Analytical chemistry has considerably benefited from the developments in the field of mass spectrometry. The high resolution, mass accuracy, and sensitivity offered by modern mass spectrometers have been essential in addressing analytical needs in numerous areas of research as well as in routine laboratory praxis. The most recent addition to the family of mass spectrometers has been the Orbitrap analyzer, making an ultrahigh-resolution mass spectrometry accessible to most life science laboratories. The Orbitrap-based instrumentation has established itself firmly in the field of proteomics, metabolomics, and metabolite analysis. Moreover, it is gaining increased popularity also in areas of bioanalysis, lipidomics, doping, as well as in drug and pesticide residue analysis. This article presents the principle of operation of the Orbitrap analyzer, its most recent technological developments, and outlook, and it reviews application areas where the Orbitrap analyzers represent the state-of-the-art solution to a multitude of analytical needs.","PeriodicalId":119970,"journal":{"name":"Encyclopedia of Analytical Chemistry","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124519533","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}