Pub Date : 2020-11-05DOI: 10.1002/9780470027318.A9909
C. Huck
The properties of natural products are related to certain classes of compounds such as alkaloids, flavonoids, and essential oils. Traditionally, separation techniques including thin-layer chromatography (TLC), liquid chromatography (LC), gas chromatography (GC), and capillary electrophoresis (CE) even hyphenated to mass spectrometry (MS) were used for the elucidation and qualitative and quantitative analyses of individual compounds. In the food industry, spectroscopic investigations using infrared radiation have been used to monitor and evaluate the composition and quality since the early 1960s. During the last four decades, near-infrared (NIR) spectroscopy (800–2500 nm; 12,500–4000 cm−1) has become one of the most attractive and used methods for analysis for the following reasons: It represents a noninvasive analytical tool allowing a fast and simultaneous qualitative and quantitative characterization of natural products and their constituents. In this contribution, the principle, technique, and methodology are described followed by a discussion of quantitative and qualitative application possibilities. Finally, some hints to helpful regulatory issues and advantages and limitations are critically evaluated. Keywords: near-infrared spectroscopy; natural product; medicinal plant; transflection; diffuse reflection; multivariate analysis; cluster analysis
{"title":"Near‐Infrared Spectroscopy in Natural Product Research","authors":"C. Huck","doi":"10.1002/9780470027318.A9909","DOIUrl":"https://doi.org/10.1002/9780470027318.A9909","url":null,"abstract":"The properties of natural products are related to certain classes of compounds such as alkaloids, flavonoids, and essential oils. Traditionally, separation techniques including thin-layer chromatography (TLC), liquid chromatography (LC), gas chromatography (GC), and capillary electrophoresis (CE) even hyphenated to mass spectrometry (MS) were used for the elucidation and qualitative and quantitative analyses of individual compounds. In the food industry, spectroscopic investigations using infrared radiation have been used to monitor and evaluate the composition and quality since the early 1960s. During the last four decades, near-infrared (NIR) spectroscopy (800–2500 nm; 12,500–4000 cm−1) has become one of the most attractive and used methods for analysis for the following reasons: It represents a noninvasive analytical tool allowing a fast and simultaneous qualitative and quantitative characterization of natural products and their constituents. In this contribution, the principle, technique, and methodology are described followed by a discussion of quantitative and qualitative application possibilities. Finally, some hints to helpful regulatory issues and advantages and limitations are critically evaluated. \u0000 \u0000 \u0000Keywords: \u0000 \u0000near-infrared spectroscopy; \u0000natural product; \u0000medicinal plant; \u0000transflection; \u0000diffuse reflection; \u0000multivariate analysis; \u0000cluster analysis","PeriodicalId":119970,"journal":{"name":"Encyclopedia of Analytical Chemistry","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127472166","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}
Pub Date : 2020-11-04DOI: 10.1002/9780470027318.A9502
M. Roldán-Pijuán, R. Lucena, S. Cárdenas
The efficiency of a given microextraction technique relies on both thermodynamic and kinetics factors. The first one defines the maximum amount of analyte that can be extracted, whereas the latter describes the rate at which the extraction equilibrium is reached. The stirring of the sample during extraction is a well-known kinetic variable that positively affects the diffusion of the analytes between the donor and acceptor phases. Although stirring/agitation is a critical and optimizing variable in most of the microextraction techniques, only a few of them integrate stirring within the extraction device. The so-called stirring/extraction integrated microextraction techniques present a high potential, and they have been the focus of a deep research in the past decade. This article is focused on the description of the main research milestones in this development, giving a wide overview of the potential and applicability of these microextraction techniques. Keywords: extraction/agitation integrated techniques; microextraction; sample preparation
{"title":"Microextraction Techniques Based on the Combination of Agitation and Extraction in the Same Device","authors":"M. Roldán-Pijuán, R. Lucena, S. Cárdenas","doi":"10.1002/9780470027318.A9502","DOIUrl":"https://doi.org/10.1002/9780470027318.A9502","url":null,"abstract":"The efficiency of a given microextraction technique relies on both thermodynamic and kinetics factors. The first one defines the maximum amount of analyte that can be extracted, whereas the latter describes the rate at which the extraction equilibrium is reached. The stirring of the sample during extraction is a well-known kinetic variable that positively affects the diffusion of the analytes between the donor and acceptor phases. Although stirring/agitation is a critical and optimizing variable in most of the microextraction techniques, only a few of them integrate stirring within the extraction device. The so-called stirring/extraction integrated microextraction techniques present a high potential, and they have been the focus of a deep research in the past decade. This article is focused on the description of the main research milestones in this development, giving a wide overview of the potential and applicability of these microextraction techniques. \u0000 \u0000 \u0000Keywords: \u0000 \u0000extraction/agitation integrated techniques; \u0000microextraction; \u0000sample preparation","PeriodicalId":119970,"journal":{"name":"Encyclopedia of Analytical Chemistry","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130503059","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}
Pub Date : 2020-11-04DOI: 10.1002/9780470027318.a9279.pub2
Y. Morisawa, I. Tanabe, Y. Ozaki
{"title":"Far‐Ultraviolet Spectroscopy in the Solid and Liquid States, Principle, Instrumentation, and Application","authors":"Y. Morisawa, I. Tanabe, Y. Ozaki","doi":"10.1002/9780470027318.a9279.pub2","DOIUrl":"https://doi.org/10.1002/9780470027318.a9279.pub2","url":null,"abstract":"","PeriodicalId":119970,"journal":{"name":"Encyclopedia of Analytical Chemistry","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134219582","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}
Pub Date : 2020-09-18DOI: 10.1002/9780470027318.a9931.pub2
G. Gunaherath, A. Gunatilaka
{"title":"Plant Steroids: Occurrence, Biological Significance, and Their Analysis","authors":"G. Gunaherath, A. Gunatilaka","doi":"10.1002/9780470027318.a9931.pub2","DOIUrl":"https://doi.org/10.1002/9780470027318.a9931.pub2","url":null,"abstract":"","PeriodicalId":119970,"journal":{"name":"Encyclopedia of Analytical Chemistry","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128153240","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}
Pub Date : 2020-09-17DOI: 10.1002/9780470027318.a9494.pub2
Michael J. Morten, D. A. Reid, E. Rothenberg
{"title":"Single‐Molecule Fluorescence Imaging Techniques","authors":"Michael J. Morten, D. A. Reid, E. Rothenberg","doi":"10.1002/9780470027318.a9494.pub2","DOIUrl":"https://doi.org/10.1002/9780470027318.a9494.pub2","url":null,"abstract":"","PeriodicalId":119970,"journal":{"name":"Encyclopedia of Analytical Chemistry","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114737471","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}
Pub Date : 2020-09-17DOI: 10.1002/9780470027318.a9351.pub2
Michelle M. Martinez, G. Khanal, D. Pappas
{"title":"Apoptosis (Programmed Cell Death) Studied by Fluorescence Spectroscopy","authors":"Michelle M. Martinez, G. Khanal, D. Pappas","doi":"10.1002/9780470027318.a9351.pub2","DOIUrl":"https://doi.org/10.1002/9780470027318.a9351.pub2","url":null,"abstract":"","PeriodicalId":119970,"journal":{"name":"Encyclopedia of Analytical Chemistry","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116362571","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}
Pub Date : 2020-06-04DOI: 10.1002/9780470027318.a9689
Robert Teuma‐Castelletti, N. Sadiq, D. Beauchemin
{"title":"Inductively Coupled Plasma Mass Spectrometry Analysis of Environmental Samples for the Quantification of Potentially Toxic Species","authors":"Robert Teuma‐Castelletti, N. Sadiq, D. Beauchemin","doi":"10.1002/9780470027318.a9689","DOIUrl":"https://doi.org/10.1002/9780470027318.a9689","url":null,"abstract":"","PeriodicalId":119970,"journal":{"name":"Encyclopedia of Analytical Chemistry","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-06-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129646696","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}
Pub Date : 2020-03-18DOI: 10.1002/9780470027318.a9276.pub2
Songyuan Ding, Xue‐Min Zhang, En-Ming You, B. Ren, Z. Tian
{"title":"Surface‐Enhanced Raman Spectroscopy: General Introduction","authors":"Songyuan Ding, Xue‐Min Zhang, En-Ming You, B. Ren, Z. Tian","doi":"10.1002/9780470027318.a9276.pub2","DOIUrl":"https://doi.org/10.1002/9780470027318.a9276.pub2","url":null,"abstract":"","PeriodicalId":119970,"journal":{"name":"Encyclopedia of Analytical Chemistry","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141221925","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}
Pub Date : 2020-03-13DOI: 10.1002/9780470027318.A9031
J. Hutchinson, C. Johns, G. Dicinoski, P. Haddad
Chemical analysis of the residues from improvised explosive devices (IEDs) has become a topical subject as a result of increased frequency of terrorist bomb attacks. There is a need to identify the type of explosive device and its composition, which in turn can assist in the identification of the perpetrators. IEDs can either be organic based (high explosives) or the more easily produced inorganic-based low explosives. Analysis of residues remaining after the deflagration of an inorganic IEDs presents several problems. A wide variety of ionic species may be present (such as unconsumed starting products, ionic species formed as part of the reaction) along with environmental or background species. Therefore, it is important that the target ions used to identify the device can be separated from other background ions present in the sample. The instrumental techniques of capillary electrophoresis (CE) and ion chromatography (IC) are proving to be ideally suited to this task. Both techniques have fundamental advantages, with CE offering highly efficient separations within a short run time, and IC offering high selectivity, sensitivity, and reproducibility. In this article, an outline of the analytical methods used in this area is presented, with particular focus on the application of CE and IC. A brief literature review of published methods is provided, along with background information on inorganic explosives, sampling techniques, portable instrumentation, and recent developments.
{"title":"Identification of Improvised Inorganic Explosive Devices by Analysis of Postblast Residues Using Ion Chromatography and Capillary Electrophoresis","authors":"J. Hutchinson, C. Johns, G. Dicinoski, P. Haddad","doi":"10.1002/9780470027318.A9031","DOIUrl":"https://doi.org/10.1002/9780470027318.A9031","url":null,"abstract":"Chemical analysis of the residues from improvised explosive devices (IEDs) has become a topical subject as a result of increased frequency of terrorist bomb attacks. There is a need to identify the type of explosive device and its composition, which in turn can assist in the identification of the perpetrators. \u0000 \u0000 \u0000 \u0000IEDs can either be organic based (high explosives) or the more easily produced inorganic-based low explosives. Analysis of residues remaining after the deflagration of an inorganic IEDs presents several problems. A wide variety of ionic species may be present (such as unconsumed starting products, ionic species formed as part of the reaction) along with environmental or background species. Therefore, it is important that the target ions used to identify the device can be separated from other background ions present in the sample. The instrumental techniques of capillary electrophoresis (CE) and ion chromatography (IC) are proving to be ideally suited to this task. Both techniques have fundamental advantages, with CE offering highly efficient separations within a short run time, and IC offering high selectivity, sensitivity, and reproducibility. \u0000 \u0000 \u0000 \u0000In this article, an outline of the analytical methods used in this area is presented, with particular focus on the application of CE and IC. A brief literature review of published methods is provided, along with background information on inorganic explosives, sampling techniques, portable instrumentation, and recent developments.","PeriodicalId":119970,"journal":{"name":"Encyclopedia of Analytical Chemistry","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122003381","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}
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