Automated Sample Preparation: Methods for GC-MS and LC-MS

An essential guide to the proven automated sample preparation process While the measurement step in sample preparation is automated, the sample handling step is manual and all too often open to risk and errors. The manual process is of concern for accessing data quality as well as producing limited reproducibility and comparability. Handbook of Automated Sample Preparation for CG-MS and LC-MS explores the advantages of implementing automated sample preparation during the handling phase for CG-MS and LC-MS. The author, a noted expert on the topic, includes information on the proven workflows that can be put in place for many routine and regulated analytical methods. This book offers a guide to automated workflows for both on-line and off-line sample preparation. This process has proven to deliver consistent and comparable data quality, increased sample amounts, and improved cost efficiency. In addition, the process follows Standard Operation Procedures that are essential for audited laboratories. This important book: Provides the information and tools needed for the implementation of instrumental sample preparation workflows Offers proven and detailed examples that can be adapted in analytical laboratories Shows how automated sample preparation can reduce cost per sample, increase sample amounts, and produce faster results Includes illustrative examples from various fields such as chemistry to food safety and pharmaceuticals Written for personnel in analytical industry, pharmaceutical, and medical laboratories, Handbook of Automated Sample Preparation for CG-MS and LC-MS offers the much-needed tools for implementing the automated sample preparation for analytical laboratories.

Table of Contents:
Foreword xiii Preface xv 1 Introduction 1 1.1 A Perspective on Human Performance 2 References 5 2 The Analytical Process 7 2.1 Laboratory Logistics 7 2.1.1 Analytical Benefits of Instrumental Workflows 9 2.1.1.1 Data Quality 11 2.1.1.2 Turnkey Operation 11 2.1.1.3 Green Analytical Chemistry 11 2.1.1.4 Productivity 12 2.1.2 Standard Operation Procedure 13 2.1.3 Economical Aspects 15 References 16 3 Workflow Concepts 19 3.1 Sample Preparation Workflow Design 19 3.1.1 Transfer of Standard Methods to Automated Workflows 20 3.1.2 Method Translation 21 3.1.2.1 Sketching the Automated Workflow 22 3.1.2.2 Robotic System Configuration 22 3.1.3 Online or Offline Configuration 25 3.2 Instrumental Concepts 25 3.2.1 Workstations 25 3.2.2 Revolving Tray Autosamplers 26 3.2.3 Selective Compliance Articulated Robots 28 3.2.4 Cartesian Robots 28 3.2.5 Multiple Axis Robots 32 3.2.6 Collaborative Robots 33 3.3 Sample Processing 35 3.3.1 Sequential Sample Preparation 35 3.3.2 Prep-ahead Mode 35 3.3.3 Incubation Overlapping 36 3.3.4 Batch Processing 36 3.3.5 Parallel Processing Workflows 38 3.3.6 Sample Identification 38 3.3.6.1 Barcodes 38 3.3.6.2 Radio-Frequency Identification Chips 40 3.4 Tool Change 41 3.4.1 Manual Tool Change 41 3.4.2 Automated Tool Change 42 3.4.3 Tool Identification 44 3.5 Object Transport 46 3.5.1 Magnetic Transport 46 3.5.2 Gripper Transport 48 3.5.3 Needle Transport 50 3.6 Vial Decapping 50 References 52 4 Analytical Aspects 55 4.1 Liquid Handling 55 4.1.1 About Drops and Droplets 55 4.1.2 Syringes 56 4.1.2.1 Precision and Accuracy 57 4.1.2.2 Syringe Needles 58 4.1.2.3 Syringe Needle Point Styles 59 4.1.2.4 Syringe Plunger Types 60 4.1.2.5 Syringe Termination 61 4.1.2.6 Operational Parameters 62 4.1.3 Vial Bottom Sensing 66 4.1.4 Pipetting 67 4.1.4.1 Air Displacement Pipettes 68 4.1.4.2 Positive Displacement Pipets 69 4.1.4.3 Pipetting Modes 69 4.1.4.4 Aspiration 71 4.1.4.5 Dispensing 73 4.1.4.6 Liquid-Level Detection 74 4.1.4.7 Liquid Classes 75 4.1.4.8 Pipet Tips 75 4.1.4.9 Functional Pipet Tips 78 4.1.4.10 Pipet Tip Materials 81 4.1.5 Dilutor/Dispenser Operation 82 4.1.6 Flow Cell Sampling 84 4.2 Solid Materials Handling 85 4.2.1 Workflows with Solid Materials 86 4.2.2 Automated Solids Dosing by Powder Dispensing 86 4.3 Weighing 88 4.4 Extraction 90 4.4.1 Liquid Extraction 91 4.4.2 Pressurized Fluid Extraction 92 4.4.2.1 Solvents and Extraction 93 4.4.2.2 Miniaturization and Automation 94 4.4.2.3 In-Cell Clean-Up 96 4.4.2.4 International Standard Methods 97 4.4.3 Liquid/Liquid Extraction 97 4.4.4 Dispersive Liquid/Liquid Micro-Extraction 100 4.4.4.1 Automated DLLME Workflows 103 4.4.4.2 DLLME for Soil and Urine 103 4.4.4.3 DLLME for Pesticides in Food 104 4.4.4.4 DLLME Hyphenation with LC 104 4.4.5 Sorptive Sample Preparation 104 4.4.5.1 Solid-Phase Micro-Extraction 105 4.4.5.2 SPME Fiber 109 4.4.5.3 SPME Arrow 112 4.4.5.4 Solid-Phase Micro-Extraction with Derivatization 116 4.4.5.5 Direct Solid-Phase Micro-Extraction Mass Spectrometry 119 4.4.5.6 Stir Bar Sorptive Extraction 121 4.4.5.7 Thin-Film Micro-Extraction 123 4.5 Clean-Up Procedures 124 4.5.1 Filtration 124 4.5.1.1 Filter Materials 125 4.5.1.2 Syringe Filter 126 4.5.1.3 Filter Vials 127 4.5.2 Solid-Phase Extraction 129 4.5.2.1 The General SPE Clean-Up Procedure 133 4.5.2.2 On-Line SPE 134 4.5.2.3 Micro-SPE Clean-Up 137 4.5.2.4 Syringe-Based Micro-SPE 141 4.5.3 Gel Permeation Chromatography 143 4.5.3.1 Standardized Methods 145 4.5.3.2 Workflow and Instrument Configuration 145 4.5.3.3 GPC-GC Online Coupling 146 4.5.3.4 Micro-GPC-GC Online Coupling 147 4.6 Centrifugation 148 4.7 Evaporation 150 4.8 Derivatization 153 4.8.1 For LC and LC-MS 154 4.8.1.1 Aromatic Acid Chlorides 154 4.8.1.2 Dansylchloride 155 4.8.1.3 Ninhydrin Reaction 155 4.8.1.4 FMOC Derivatization 155 4.8.2 For GC and GC-MS 156 4.8.2.1 Silylation 156 4.8.2.2 Acetylation 157 4.8.2.3 Methylation 157 4.8.2.4 Methoxyamination 158 4.8.2.5 Fluorinating Reagents 158 4.8.3 For GC and GC-MS In-Port Derivatization 159 4.9 Temperature Control 163 4.9.1 Heating 163 4.9.1.1 Incubation Overlapping 163 4.9.2 Cooling 164 4.10 Mixing 166 4.10.1 Vortexing 166 4.10.2 Agitation 167 4.10.3 Spinning 169 4.10.4 Mixing with Syringes 169 4.10.5 Cycloidal Mixing 169 References 171 5 Integration into Analysis Techniques 191 5.1 GC Volatiles Analysis 191 5.1.1 Static Headspace Analysis 192 5.1.1.1 Overcoming Matrix Effects 194 5.1.1.2 Measures to Increase Analyte Sensitivity 195 5.1.1.3 Static Headspace Injection Technique 195 5.1.2 Multiple Headspace Quantification 197 5.1.3 Dynamic Headspace Analysis 201 5.1.3.1 Purge and Trap 202 5.1.3.2 Dynamic Headspace Analysis with In-Tube Extraction 204 5.1.3.3 Dynamic Headspace Analysis Using Sorbent Tubes 207 5.1.3.4 Needle Trap Microextraction 208 5.1.4 Tube Adsorption 210 5.2 GC Liquid Injection 222 5.2.1 Sandwich Injection 222 5.2.2 Hot Needle Injection 222 5.2.3 Liquid Band Injection 224 5.2.4 Automated Liner Exchange 226 5.3 LC–GC Online Injection 230 5.4 LC Injection 233 5.4.1 Dynamic Load and Wash 234 5.4.2 Using LC Injection Ports with a Pipette Tool 235 References 237 6 Solutions for Automated Analyses 247 First About Safety 248 6.1 Dilution 248 6.1.1 Geometric Dilution of Reference Standards 248 6.1.2 Dilution for Calibration Curves 251 6.1.3 Preparation of Working Standards 256 6.2 Derivatization 259 6.2.1 Silylation 260 6.2.2 SPME On-Fiber Derivatization 262 6.2.3 Metabolite Profiling by Methoximation and Silylation 266 6.3 Taste and Odor Compounds Trace Analysis 271 6.4 Sulfur Compounds in Tropical Fruits 276 6.5 Ethanol Residues in Halal Food 284 6.6 Volatile Organic Compounds in Drinking Water 289 6.7 Geosmin and 2-MIB 295 6.8 Solvent Elution from Charcoal 301 6.9 Semivolatile Organic Compounds in Water 304 6.10 Polyaromatic Hydrocarbons in Drinking Water 315 6.11 Fatty Acid Methylester 321 6.11.1 Application 321 6.12 MCPD and Glycidol in Vegetable Oils 328 6.13 Mineral Oil Hydrocarbons MOSH/MOAH 339 6.14 Pesticides Analysis – QuEChERS Extract Clean-Up 347 6.15 Glyphosate, AMPA, and Glufosinate by Online SPE-LC-MS 362 6.16 Pesticides, PPCPs, and PAHs by Online-SPE Water Analysis 368 6.17 Residual Solvents 375 6.18 Chemical Warfare Agents in Water and Soil 382 6.19 Shale Aldehydes in Beer 390 6.20 Phthalates in Polymers 394 References 400 A Appendix 413 A.1 Robotic System Control 413 A.1.1 Maestro Software 413 A.1.2 Chronos Software 414 A.1.3 Graphical Workflow Programming 415 A.1.4 Sample Control Software 416 A.1.5 Local System Control 417 A.1.6 Script Control Language 418 A.2 System Maintenance 418 A.2.1 Syringes 418 A.2.1.1 Manual Syringe Handling 418 A.2.1.2 Syringe Cleaning 418 A.2.1.3 Plunger Cleaning 419 A.2.1.4 Needle Cleaning 419 A.2.1.5 Confirming the Dispensed Volume of a Syringe 420 A.2.1.6 Sterilization 420 A.2.2 Pipettes 421 A.2.2.1 Calibration 421 A.2.2.2 Pipette Parts Maintenance 421 A.2.3 System Hardware Maintenance Schedule 422 A.3 Syringe Needle Gauge 423 A.4 Pressure Units Conversion 425 A.5 Solvents 425 A.5.1 Solvent Miscibility 425 A.5.2 Solvent Stability 428 A.5.2.1 Halogenated Solvents 428 A.5.2.2 Ethers 429 A.5.3 Solvent Viscosity 429 A.6 Material Resistance 429 A.6.1 Glass 432 A.6.2 Polymers 432 A.6.3 Stainless Steel 433 References 437 Glossary 441 References 451 Index 453