Isotopic Analog as the Internal Standard for Quantitative Determination PDF Download
Are you looking for read ebook online? Search for your book and save it on your Kindle device, PC, phones or tablets. Download Isotopic Analog as the Internal Standard for Quantitative Determination PDF full book. Access full book title Isotopic Analog as the Internal Standard for Quantitative Determination by YS. Ho. Download full books in PDF and EPUB format.
Author: YS. Ho
Publisher:
ISBN:
Category : 9-Carboxy-11-Nor-Delta-9-Tetrahydrocannabinol
Languages : en
Pages : 10
Get Book Here
Book Description
Mass spectra of several commonly abused drugs and their deuterated analogs are compared and evaluated with emphasis on the selection of suitable ions for selective ion monitoring when the isotopic analogs are used as the internal standards in a quantitative determination process. Ions selected for this purpose should be of relative high mass with significant intensities, retain at least three labeling isotopes, and be free of interference from the corresponding compound.
Author: YS. Ho
Publisher:
ISBN:
Category : 9-Carboxy-11-Nor-Delta-9-Tetrahydrocannabinol
Languages : en
Pages : 10
Get Book Here
Book Description
Mass spectra of several commonly abused drugs and their deuterated analogs are compared and evaluated with emphasis on the selection of suitable ions for selective ion monitoring when the isotopic analogs are used as the internal standards in a quantitative determination process. Ions selected for this purpose should be of relative high mass with significant intensities, retain at least three labeling isotopes, and be free of interference from the corresponding compound.
Author: RH. Liu
Publisher:
ISBN:
Category : Benzoylecgonine
Languages : en
Pages : 5
Get Book Here
Book Description
Empirical data is used to demonstrate the observation and quantification of benzoylecgonine in negative test samples when high concentrations of deuterated benzoylecgonine are used as the internal standard in the assay process. On the quantitative determination of true positive samples, inaccuracy introduced by the isotopic impurity of the internal standard is calculated as a function of the impurity and the concentration levels of the internal standard used.
Author: WT. Chang
Publisher:
ISBN:
Category : Barbiturate
Languages : en
Pages : 9
Get Book Here
Book Description
The following analyte/isotope-labeled internal standard (IS) systems areadapted to further study the interference phenomenon previously reported fromour laboratory-the intensity ratio of the ion-pair designated for aspecific analyte/2H-analog system increases as the solvent used to reconstitutethe extraction/derivatization residue is increased: (a) Three analyte/2H-analogpairs with 2H-atoms positioned at allylic sites (butalbital, secobarbital,methohexital); (b) Two analyte/2H-analog pairs without these structural features(pentobarbital, phenobarbital); and (c) Two analyte/13C-analog pairs (butalbital,secobarbital) Major experimental parameters adapted in this study include:(a) Varying reconstitution solvent volume while keeping a constant analyte/ISconcentration ratio; (b) Varying analyte/IS concentration ratio; (c) Varyinggas chromatograph (GC) injection port temperature; and (d) Varying GC columntemperature programming conditions, rendering difference in the degree ofoverlap of the peaks derived from the analyte and the 2H-analog. This studyresults in the following observations: (a) Changes in the intensity ratioof the ionpair designated for a specific analyte/2H-analog system depend onmolecular abundance, regardless of whether the 2H-atoms are positioned atactive allylic positions or not-thus, ruling out hydrogen/deuteriumexchange as the cause of the observed interference phenomenon; (b) Variationsin GC injection port temperature do not alter the observed interference phenomenon-thus,ruling out chemical reactions at the injection port as the underlying cause;(c) Variations in peak-overlapping between the analyte and the 2H-analog,facilitated by changing GC column programming conditions, alter the observedinterference phenomenon. Abundance of the analyte and the 2H-analog and theiroverlapping characteristic in the mass spectrometer ion source are believedto be the underlying cause of the observed interference phenomenon. The interferencephenomenon observed for a specific analyte/2H-analog system has significantconsequences on the linearity of the thereby generated calibration curves.Nonlinear approaches can better describe the calibration data and are neededmore in comparison to systems in which 13C-analogs are used as the ISs.
Author: RH. Liu
Publisher:
ISBN:
Category : Barbiturates
Languages : en
Pages : 7
Get Book Here
Book Description
Internal standards are commonly used for the quantitative determination of drugs of abuse and their metabolites (drug/metabolite) in biological fluids and tissues by the selective ion monitoring (SIM) gas chromatography/mass spectrometry (GC/MS) procedure. Analogs of drugs/metabolites that are labeled with three or more deuterium atoms (Isotopic analog) at appropriate positions are considered to be the most effective internal standards for these applications. Before a specific deuterated analog can be adopted as an internal standard in a GC/MS assay, the mass spectrum of the compound or its derivative must be evaluated along with the corresponding spectrum from the parent drug/metabolite. There should be an adequate number of sufficiently high-mass ions (typically three for the drug/metabolite and two for the isotopic analog) that can be attributed to each analyte, and these ions should be sufficiently free of interference from the other analyte of the pair (cross-contribution) Interferences may be caused by the presence of an isotopic impurity in the deuterated analog (extrinsic factor) or may be due to the ion fragmentation characteristics of the compound (intrinsic factor) The extrinsic factor may be corrected by the manufacturer with different synthetic methods and purification procedures, while the intrinsic factor may be partially or wholly corrected through the use of different chemical derivatives (sample preparation stage) or different ionization (GC/MS assay stage) procedures.
Author: Wenkui Li
Publisher: John Wiley & Sons
ISBN: 111867135X
Category : Science
Languages : en
Pages : 709
Get Book Here
Book Description
Consolidates the information LC-MS bioanalytical scientists need to analyze small molecules and macromolecules The field of bioanalysis has advanced rapidly, propelled by new approaches for developing bioanalytical methods, new liquid chromatographic (LC) techniques, and new mass spectrometric (MS) instruments. Moreover, there are a host of guidelines and regulations designed to ensure the quality of bioanalytical results. Presenting the best practices, experimental protocols, and the latest understanding of regulations, this book offers a comprehensive review of LC-MS bioanalysis of small molecules and macromolecules. It not only addresses the needs of bioanalytical scientists working on routine projects, but also explores advanced and emerging technologies such as high-resolution mass spectrometry and dried blood spot microsampling. Handbook of LC-MS Bioanalysis features contributions from an international team of leading bioanalytical scientists. Their contributions reflect a review of the latest findings, practices, and regulations as well as their own firsthand analytical laboratory experience. The book thoroughly examines: Fundamentals of LC-MS bioanalysis in drug discovery, drug development, and therapeutic drug monitoring The current understanding of regulations governing LC-MS bioanalysis Best practices and detailed technical instructions for LC-MS bioanalysis method development, validation, and stability assessment of analyte(s) of interest Experimental guidelines and protocols for quantitative LC-MS bioanalysis of challenging molecules, including pro-drugs, acyl glucuronides, N-oxides, reactive compounds, and photosensitive and autooxidative compounds With its focus on current bioanalytical practice, Handbook of LC-MS Bioanalysis enables bioanalytical scientists to develop and validate robust LC-MS assay methods, all in compliance with current regulations and standards.
Author: Ray H. Liu
Publisher: CRC Press
ISBN: 142009498X
Category : Law
Languages : en
Pages : 506
Get Book Here
Book Description
The analysis of drugs and their metabolites in biological media are now expected to routinely achieve 20% accuracy in the ng/mL concentration level. Therefore, the availability and the selection of quality ion-pairs designating the analytes and their isotopically labeled analogs (ILAs) are important considerations in achieving the accuracy of qua
Author: Jose Alonso
Publisher: Royal Society of Chemistry
ISBN: 1788018168
Category : Science
Languages : en
Pages : 473
Get Book Here
Book Description
Isotope Dilution Mass Spectrometry (IDMS) has become an essential tool in research laboratories and is increasingly used in routine analysis labs (including environmental, food safety and clinical applications). This is the first textbook to present a comprehensive and instructive view of the theory and applications of this growing technique. The main objective of this book is to cover the theory and applications of Isotope Dilution in Analytical Chemistry. The scope is comprehensive to include elemental analysis, speciation analysis, organic analysis and biochemical and clinical analysis together with applications in metabolism studies and traceability of goods. Until now there have been no books published with the same general scope (only book chapters on particular applications). This is a textbook focused at post-graduate level covering the basic knowledge required for doctoral studies in this field. Isotope Dilution Mass Spectrometry will also outline practical applications of interest for routine testing laboratories where isotope dilution procedures are implemented or can be implemented in the future. This unique book covers all the theoretical and practical aspects of Isotope Dilution Mass Spectrometry (IDMS). Due to the increasing application of IDMS in many research laboratories and the increasing implementation of IDMS methodologies in routine testing laboratories, scientists in industry and working in or affiliated to this area will this an invaluable source of information. Concerning the theoretical aspects, the authors present a uniform theoretical background which grows from previous developments in Organic, Speciation and Elemental analysis both in their own laboratory and in other laboratories around the world. This general approach will be simpler and will also include new emerging fields such as quantitative proteomics and metabolism studies.
Author: David Glick
Publisher: John Wiley & Sons
ISBN: 0470110910
Category : Science
Languages : en
Pages : 507
Get Book Here
Book Description
Biochemical analysis is a rapidly expanding field and is a key component of modern drug discovery and research. Methods of Biochemical Analysis provides a periodic and authoritative review of the latest achievements in biochemical analysis. Founded in 1954 by Professor David Glick, Methods of Biochemical Analysis provides a timely review of the latest developments in the field.
Author: Ray Marsili
Publisher: CRC Press
ISBN: 0824741676
Category : Technology & Engineering
Languages : en
Pages : 442
Get Book Here
Book Description
Written from a practical, problem-solving perspective, this reference explores advances in mass spectrometry, sample preparation, gas chromatography (GC)-olfactometry, and electronic-nose technology for food, cosmetic, and pharmaceutical applications. The book discusses the chemical structures of key flavor and fragrance compounds and contains numerous examples and chromatograms and emphasizes novel solid-phase microextraction procedures. It includes coverage of isolation and concentration of odor impact chemicals prior to GC manipulation; time-of-flight mass spectrometers and electronic-nose instrumentation; how to identify chemicals responsible for flower scents; and more.
Author: J. R. Chapman
Publisher: John Wiley & Sons
ISBN: 9780471958314
Category : Science
Languages : en
Pages : 366
Get Book Here
Book Description
Practical Organic Mass Spectrometry Second Edition A Guide for Chemical and Biochemical Analysis J. R. Chapman Kratos Analytical Instruments, Manchester, UK This volume provides a comprehensive survey of current techniques for the use of mass spectrometry in organic chemical and biochemical analysis. Every aspect of modern instrumentation and technique is discussed. The new edition retains the effective division of material applied in the author's previous volume-theory, practical requirements and applications. However, it has been thoroughly revised and extended to include all recent advances in mass spectrometry, and is complete with extensive references. This is essentially a book for the practising mass spectroscopist which will appeal to both biochemists and organic chemists. Some familiarity with basic principles is assumed but the author has employed a style which makes this volume suitable for beginners and more advanced students alike. The present volume will be particularly valuable to anyone who wishes to evaluate and compare alternative techniques. Main Contents-Instrumentation; Sample Introduction; Chemical lonization (lon-Molecule Reactions); Negative lon Chemical lonization; The lonization of Labile Materials (Part I); The lonization of Labile Materials (Part II); Tandem Mass Spectrometry (The Dissociation of lons); Quantitative Analysis.
