HANDBOOK OF DRUG ANALYSIS

Transcription

1 HANDBOOK OF DRUG ANALYSIS APPLICATIONS IN FORENSIC AND CLINICAL LABORATORIES Ray H. Liu Daniel E. Gadzala American Chemical Society Washington, DC

2 Contents Dedication Foreword Preface About the Authors Introduction iii v vii ix xix SECTION I NATURE OF DRUG ABUSE AND SAMPLE CHARACTERISTICS AND PRETREATMENT Chapter 1. Nature of Abused Drugs and Sample Characteristics Drug Abuse and Drug Testing 3 Assessing the Extent of Drug Use 3 Evolution of the Nation's Antidrug Policy 4 The Response and Contribution of the Scientific Communities: Drug Testing 4 Drug Classification 6 Chemical Structure 7 Legal Schedule 7 Pharmacological Effect 8 Samples in Criminal Investigations 8 Illicit Solid Dosage Forms 8 Carriers 9 Unintended Impurities 9 Intended Combinations 11 Multiple Active Ingredients 11 Excipients and Adulterants 12 Unexpected Contents 13 Counterfeits 13 Look-Alike and Designer Drugs 14 Biological Samples 14 Drug Metabolism 14 Administration, Absorption, Distribution, and Excretion of Drugs 15 Exposure 17 Distribution 17 Excretion 18 Biotransformation of Drugs 18 General Drug Biotransformation Patterns 19 Metabolites of Drugs Commonly Found in Forensic Analysis 19 Characteristics of Biological Samples 19 Biological Fluids 21 Blood, Plasma, and Serum 22 xi

3 Urine 22 Saliva 22 Postmortem Tissues 23 Vitreous Humor 24 Liver 25 Brain 25 Stomach Contents 26 Bile 26 Muscle 26 Unconventional Samples 26 Hair 26 Sweat 28 Bone, Nails, and Biological Stains 28 Meconium 29 Insect Larvae 29 References 29 Chapter 2. Sample Pretreatment Extraction of Drugs in Dosage Forms 35 ph Adjustment 35 Extraction Efficiency 36 Specific Applications 36 Extraction of Drugs in Plant Materials 38 Pretreatment of Biological Samples 38 Acid and Enzyme Hydrolysis of Conjugated Drugs 39 Protein Removal 40 Inorganic Acids and Salts 40 Organic Solvent Precipitation 40 Proteolytic Enzymes 41 Extraction 41 Liquid-Liquid Extraction of Organic-Solvent-Soluble Drugs 42 Solvent Selection 42 Removal or Identification of Co-Extracted Materials 44 Extraction-Derived Artifacts 44 Extraction of Water-Soluble Drugs 45 Liquid-Solid Extraction of a Lyophilized Sample 45 Ion-Pair Extraction 45 Salting-Out 45 Formation of Derivatives Favoring Organic Solvent Extraction 46 Solid-Phase Extraction 46 Solid-Phase Adsorbents and Intermolecular Forces 47 Automation 49 Application Examples 49 References 51 SECTION II PRELIMINARY TEST AND CHROMATOGRAPHIC METHODS Chapter 3. Color Tests xii Comparison of Color Formation with a Color Chart Reference 57 Multiple Reagent Testing 58 References 60

4 Chapter 4. Thin-Layer Chromatography TLC Systems 61 Reproducibility 62 Correction of Retention Data 62 Evaluation of System Separation Power 63 Selection of Developing Systems 63 Detection 65 Standardized Operation 65 References 70 Chapter 5. Immunoassay Immunoassay and Workplace Drug Urinalysis 73 The Basis of Immunoassays 73 On-Site versus Laboratory-Based Immunoassay Kits 74 Role of Immunoassay in Workplace Drug Urinalysis 74 Correlation of Preliminary-Test and Confirmation-Test Results 75 Methodologies and Cross-Reactivities 76 Radioimmunoassay 76 Basic Methodology 76 Cross-Reactivities 77 Application and Sample Characteristics 82 Enzyme Immunoassay 84 Basic Methodology 84 Cross-Reactivities 87 Application and Sample Characteristics 94 Fluorescence Polarization Immunoassay 94 Basic Methodology 94 Cross-Reactivity 95 Application and Sample Characteristics 96 Particle Immunoassay 101 Basic Methodology 101 Interference 102 Targeted Analytes Derived from Unintended Exposure, Food Consumption, and Licit Medication 104 Unknown Cross-Reacting Compounds 104 Nonspecific Binding 105 Detection Mechanism 105 Adulterants 106 Simultaneous Multiple-Drug Detection 109 Comparison of Immunoassay Performance Characteristics 110 Consistency of Immunoassay and GC-MS Test Results 111 Assay Precision and Sensitivity HI Quantitative Data Correlation Between GC-MS and Different Immunoassays 113 Selection of Samples for Correlation Studies 113 Cannabinoids 114 Correlation Studies of Commercial Immunoassays 114 Interpretation of Correlation Parameters 114 Cocaine 117 Opiates 118 Quantitative Data Correlation of GC-MS and Immunoassays Performed with Reagents Manufactured at Different Time Periods 119 Selection of Immunoassay Cutoff in Workplace Drug Urinalysis 119 Development and Comparison of "Quick Test" Immunoassay Kits 121 References 124 xiii

5 Chapter 6. Chromatographic Methods Classification and Complementary Nature of Chromatographic Methods 129 Operational Characteristics of GC and HPLC 130 Gas Chromatography 131 Basic Operational Principles and Parameters 131 Stationary Phases 132 Optimization of Analysis Selection of Column Internal Diameter, Stationary-Phase Film Thickness, Carrier Gas, and Stationary Phases 132 Optimization of Analysis Speed 132 Limitations 134 Chemical Derivatization 134 Merits of Chemical Derivatization 134 Compatibility with the Chromatographic Environment 134 Achieving Required Separation or Improving Separation Efficiency 136 Improvement of Detection and Structure-Elucidation Efficiency 136 Chemical-Derivatization Reactions and Practical Considerations 138 Representative Derivatization Approaches 140 Retention Data as a Basis for Preliminary Drug Identification 141 Identification Based on Relative Retention Time Data 141 Identification Based on Retention Index Data 141 Comparability of Retention Indices Obtained under Various Conditions 141 Utilization of Non-Paraffins as References 143 Detection Systems 145 Basic Operational Principle 145 Applications 145 High-Pressure Liquid Chromatography 146 Basic Operational Principles and Parameters of HPLC 148 Solvent Characteristics and Resolution Optimization 149 Stationary Phase 152 Retention Data as a Basis for Preliminary Drug Identification 153 Limited Screening 153 General Screening 158 Standardization of Retention Data 158 Capacity Factor and Relative Adjusted Capacity Factor 158 Retention Index 159 Further Improvements 160 Detection Systems 161 Absorption 161 Fluorescence 163 Electrochemical Detection 164 References 165 SECTION III IDENTIFICATION METHODS Chapter 7. Molecular Spectrophotometry UV-Visible Spectrophotometry 173 Correlation of Electronic Absorption Spectra with Molecular Structure 174 Applications Involving Chemical Derivatization 175 Extended Techniques and Their Applications 176 Infrared Spectrophotometry 176 Basic Operational Parameters 176 xiv

6 Spectrum-Structure Correlation 178 Practical Considerations and Spectrometric Examination 181 Sample Preparation for Spectrometric Examination 181 Approaches and Cautions for Comparing Unknown Spectra with Known Collections 182 Other Molecular Spectrophotometry 182 Fluorescence Spectrophotometry 182 Circular Dichroism 183 References 184 Chapter 8. Nuclear Magnetic Resonance Spectrometry Magnetic Resonance 185 Chemical Shift and Spin-Spin Coupling 185 Proton Nuclear Magnetic Resonance ('H NMR) Spectrometry 186 'H NMR Spectrometry of Commonly Abused Drugs 186 Differentiation of Enantiomers 188 Carbon-13 Nuclear Magnetic Resonance ( 13 C NMR) Spectrometry 191 References 194 Chapter 9. Mass Spectrometry General Trend and Development 195 Sample Introduction 196 Ionization Methods 196 Recent Developments in MS 197 Computer Applications: Data Acquisition and Conversion, Data Retrieval, Spectrum Interpretation, Mathematical and Statistical Treatment of MS Data, and Targeted-Compound Analysis 198 MS Characteristics of Commonly Abused Drugs 199 Amphetamines and Related Amine Drugs 200 Morphine and Related Alkaloids 202 Marijuana and Other Cannabinoid-Containing Materials 208 Barbiturates 211 Cocaine 213 Phencyclidine and Analogs 215 Lysergic Acid and Related Compounds 217 oc-methylfentanyl 219 Methaqualone and Mecloqualone 219 Benzodiazepines 220 Methadone 221 Analytical Approaches 222 Tandem MS 222 Chemical Derivatization for Enhancing Detection and Structure Elucidation 224 Generation of Favorable Derivatives to Improve the Limit of Detection 224 Generation of Favorable Mass Spectra through Derivatization 224 Generation of Ions More Suitable for Quantification 224 Generation of Ions Helpful for Structure Elucidation 224 Quantitative Analysis 226 Using an Isotope-Labeled Analog as an IS 226 Criteria for Selecting an Isotopic Analog as the IS 226 One-Point Calibration 227 Calibration Curve 227 Further Considerations 228 Instrumental Parameters 230 xv

7 Chromatography-MS Applications 230 GC-MS 230 Operational Parameters 230 Precautions and Minimal Requirements for Using SIM Data as Qualitative Analysis Criteria 230 Precautions and Minimal Requirements for Using SIM Data for Quantitative Determination 231 Application of GC-MS Protocols in Drug Urinalysis: Targeted-Compound Identification 232 Liquid Chromatography-MS 232 References 236 SECTION IV DEVELOPING TECHNOLOGIES AND ANALYTICAL ISSUES Chapter 10. Developing Analytical Technologies Capillary Electrophoresis 247 Applications of CZE and MECC 248 Important Operational Parameters: ph, Buffer Additives, and Organic Modifiers 251 Development in Detection Technologies 253 Supercritical Fluid Extraction and Chromatography 254 Operational Parameters 255 Supercritical Fluid Chromatography 258 References 258 Chapter 11. Sample Differentiation Physical Characterization of Tablets and Capsules 261 Impurity and Component Identification and Quantification 262 Amphetamines 262 Cocaine 263 Cannabis 264 Opiates 265 Analysis of Naturally Occurring Isotopes 267 Basic Methodology 267 Sample Preparation 267 Isotope-Ratio Determination 268 Applications 269 Intrinsic Sample Isotope-Ratio Variation as a Basis for Differentiation 269 Stable-Isotope Coding as a Tracing Mechanism: Methamphetamine Example 272 Analysis of Diastereoisomers and Enantiomers 273 NMR Spectrometry 273 Chromatographic Methods 274 GC Separation of Amphetamine and Methamphetamine Enantiomers 274 Chiral Column 274 Achiral Column 274 Liquid Chromatography 275 Mode of Separation 275 Applications 277 Conclusions 278 References 279 xvi

8 Chapter 12. Interpretation of Test Results Sample Adulteration 283 In Vivo Adulteration 283 In Vitro Adulteration 283 Positive Results Derived From Nonabuse Exposure 284 Unintended Exposure 285 Marijuana 285 Cocaine 285 Others 287 Food and Licit Medication 287 Quantification 288 Concentration Near the Cutoff 289 Quantification Corrected with Creatinine Content and Urinary ph 289 Time Lapse Between Drug Exposure and Sample Collection 290 Stability 291 Identification and Quantification of Drug Metabolites 283 References 294 APPENDICES Appendix I. Drug Classification and Other Pertinent Information 298 Appendix n. Metabolites of Common Drugs 313 Appendix III. Structural Frameworks for Drugs and Metabolite Listed in Appendices I and II 331 Appendix IV. Functional Groups That Complete the Structural Frameworks (Appendix III) for Drugs Listed in Appendices I and II 343 Index 359 xvn