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 Introduction 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 Concluding Remarks References Isotopically Labeled Analog of the Analyte as Internal Standard for Drug Quantitation — Chemical Derivatization and Data Collection and Evaluation Introduction Chemical Derivatization Production of Most Favorable Ion-Pairs for Drug Quantitation Exemplar Studies 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 Concluding Remarks References Part Two. Mass Spectra of Commonly Abused Drugs and Their Isotopically Labelled Analogs in Various Derivatization Forms Table of Contents for Appendix One Stimulants Opioids Hallucinogens Depressants/Hypnotics Antianxiety Agents Antidepressants Others Part Three. Cross-Contributions of Ion Intensity Between Analytes and Their Isotopically Labeled Analogs in Various Derivatization Forms Table of Contents for Appendix Two Stimulants Opioids Hallucinogens Depressants/Hypnotics Antianxiety Agents Antidepressants Others Index

Ray H. Liu is a professor in the Department of Medical Technology at Fooyin University in Taiwan and professor emeritus in the Department of Justice Sciences at the University of Alabama in Birmingham. Sheng-Meng Wang is a professor of forensic science and director of scientific laboratories at Central Police University in Taiwan. Dennis V. Canfield is the manager of the Bioaeronautical Sciences Research Laboratory at the U.S. Federal Aviation Administration’s Civil Aerospace Medical Institute (CAMI) in Oklahoma City, Oklahoma.