Quantitation and Mass Spectrometric Data of Drugs and Isotopically Labeled Analogs
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 quantitation results. Assisting scientists with this process, Quantitation and Mass Spectrometric Data of Drugs and Isotopically Labeled Analogs provides an extremely valuable reference for labs involved in the analysis of therapeutic and abused drugs.
Part One of this comprehensive volume illustrates approaches, mechanisms, and challenges pertaining to the use of isotopic analogs as internal standards for drug quantitation. The second section is a systematic compilation of full-scan mass spectra of drugs and their analogs, as parent compounds and as derivatives resulting from various chemical derivatization approaches, commonly encountered in today’s labs. Based on the mass spectra data presented in the second section, Part Three provides corresponding tables of ion-pairs which can potentially be adapted to designate the drugs and their isotopic analogs in the analytical processes. Relative quality of these ion-pairs (cross-contribution to the intensity of these ions by their isotopic analogs) is included in these tables.
With more than 1500 full-scan mass spectra and quick access data tables, this text represents the authors’ years of work compiling mass spectra of the many chemical derivatization forms of drugs, their metabolites, and their isotopically labeled counterparts. The unparalleled scope of this compilation makes it a critical one-stop reference for those involved in drug analyses of biological specimens and interpretation of results.
Part One. Isotopically Labeled Analog as Internal Standard for Drug Quantitation — Methodology
Quantitation of Drug in Biological Specimen — Isotopically Labeled Analog of the Analyte as Internal Standard
Significance of Accurate Quantitation
Preferred Calibration Method
Internal Standard and Quantitation Ions
Inadequate Isotopic Purity — An Extrinsic Factor
Cross-Contribution Derived from Ion Fragmentation Mechanism — An Intrinsic Factor
Fitting Calibration Data
2H- Versus 13C-Analogs as Internal Standards
Isotopically Labeled Analog of the Analyte as Internal Standard for Drug Quantitation — Chemical Derivatization and Data Collection and Evaluation
Production of Most Favorable Ion-Pairs for Drug Quantitation
Isotopically Labeled Analogs and Chemical Derivatization Groups
Ion Intensity Cross-Contribution Data
Full-Scan Mass Spectra
Selected Ion Monitoring and Calculation of Cross-Contribution Data:
Direct Measurement, Normalized Direct Measurement, Internal Standard Method, Standard Addition Method
Assessing the Accuracy of Empirically Determined Cross-Contribution Data:
Experimentally Observed Concentration, Theoretically Calculated Concentration, Comparing Empirically Derived and Theoretically Calculated Concentrations — Graphic Presentation, Summary
Compilation of Full-Scan Mass Spectra and Ion Intensity Cross-Contribution Tables:
Derivatization Procedures, Instrumentation, and Analytical Parameters
Collection of Mass Spectrometric Data
Ion Intensity Cross-Contribution Data
Part Two. Mass Spectra of Commonly Abused Drugs and Their Isotopically Labelled Analogs in Various Derivatization Forms
Table of Contents for Appendix One
Part Three. Cross-Contributions of Ion Intensity Between Analytes and Their Isotopically Labeled Analogs in Various Derivatization Forms
Table of Contents for Appendix Two
The information presented in this book is definitely of value to any laboratory engaged in toxicology analysis and the quantification of drugs.
—Maria Reid, Royal Canadian Mounted Police, Canadian Society of Forensic Science, Vol. 43, No. 1, March 2010
The book is of obvious utility to those analysts who work in
drug analysis and to those who are confronted occasionally with
a drug-analysis problem. The strategies outlined in this work are
important to anyone who is conducting trace analysis by
chromatography coupled with mass spectrometry.
—Michael L. Gross, Journal of the American Society for Mass Spectrometry