HPLC-MS Handbook for Practitioners

Stavros Kromidas studied biology and chemistry at the University of Saarbrücken, where he obtained his Ph.D. degree on the development of new chiral stationary phases for HPLC in 1983. After working for Waters GmbH for five years, he founded NOVIA GmbH, a provider of professional training and consulting in analytical chemistry, serving as the CEO until 2001. Since 2001 he works as an independent consultant for analytical chemistry, based in Saarbrücken (Germany). For more than 20 years he has regularly held lectures and training courses on HPLC, and has authored numerous articles and several books on various aspects of chromatography.

• Preface XIThe Structure of HPLC-MS for Practitioners XIIIList of Contributors XVPart I Overview, Pitfalls, Hardware-Requirements 11 State of the Art in the LC/MS 3O. Schmitz1.1 Introduction 31.2 Ionization Methods at Atmospheric Pressure 51.2.1 Overview of API Methods 61.2.2 ESI 61.2.3 APCI 81.2.4 APPI 91.2.5 APLI 101.2.6 Determination of Ion Suppression 111.2.7 Best Ionization for Each Question 111.3 Mass Analyzer 121.4 Future Developments 131.5 What Should You Look forWhen Buying a Mass Spectrometer? 14References 152 Technical Aspects and Pitfalls of LC/MS Hyphenation 19M.M. Martin2.1 Instrumental Requirements for LC/MS Analysis – Configuring the Right System for Your Analytical Challenge 202.1.1 (U)HPLC andMass Spectrometry – Not Just a Mere Front-End 202.1.2 UHPLC System Optimization – Gradient Delay and Extra-column Volumes 212.1.3 Does YourMass Spectrometer Fit Your Purpose? 332.1.4 Data Rates and Cycle Times ofModernMass Spectrometers 382.1.5 Complementary Information by Additional Detectors or Mass SpectrometryWon’t Save theWorld 392.2 LC/MS Method Development and HPLC Method Adaptation – How toMakeMy LC Fit forMS? 432.2.1 Method Development LC/MS – LC Fits theMS Purposes 442.2.2 Converting Classical HPLC Methods into LC/MS 532.3 Pitfalls and Error Sources – Sometimes Things Do GoWrong 542.3.1 No Signal at All 542.3.2 Inappropriate Ion Source Settings and Their Impact on the Chromatogram 562.3.3 Ion Suppression 582.3.4 Unknown Mass Signals in the Mass Spectrum 592.3.5 Instrumental Reasons for the Misinterpretation ofMass Spectra 652.4 Conclusion 682.5 Abbreviations 69References 703 Aspects of the Development of Methods in LC/MS Coupling 73T. Teutenberg, T. Hetzel, C. Portner, S. Wiese, C. vom Eyser, andJ. Tuerk3.1 Introduction 733.2 From Target to Screening Analysis 743.2.1 Target Analysis 743.2.2 Suspected-Target Screening 743.2.3 Non-target Screening 743.2.4 Comparable Overview of the Different Acquisition Modes 753.3 The Optimization of Parameters in Chromatography andMass Spectrometry 753.3.1 Requirements and Recommendations for HPLC/MS Analysis Taking DIN 38407-47 as an Example 753.3.2 The Definition of Critical Peak Pairs in the Context of HPLC/MS Coupling 773.3.3 The Separation of Polar Components fromthe Column Void Time 793.3.4 Determining the HPLC Method Parameters Using the Example of the Separation of Selected Pharmaceuticals 803.3.5 Carrying out Screening Experiments 843.3.6 Evaluation of the Data and Discussion of the Influencing Parameters 863.3.7 Using Simulation Software for Fine Optimization 983.3.8 Choosing the Stationary Phase Support 993.3.9 The Influence of the Inner Column Diameter and theMobile Phase Flow Rate 1033.3.10 The Influence of the Injection Volume 1043.3.11 Establishing theMass Spectrometric Parameters 1153.3.12 Optimization of theMass Spectrometric Parameters 1173.3.13 Quantification Using LC/MS 1223.3.14 Screening Using LC/MS 1283.3.15 Miniaturization – LC/MS Quo Vadis? 132References 135Part II Tips, Examples, Trends 1394 LC/MS for Everybody/for Everything? – LC/MS Tips 141F. Mandel4.1 Introduction 1414.2 Tip Number 1 1424.2.1 Choosing the Right LC/MS Interface 1424.3 Tip Number 2 1484.3.1 Which Mobile Phases Are Compatible with LC/MS? 1484.4 Tip Number 3 1494.4.1 Phosphate Buffer – The Exception 1494.5 Tip Number 4 1504.5.1 Paired Ions 1504.5.2 Which “Antidote” Is Available? 1514.5.3 Summary 1524.6 Tip Number 5 1524.6.1 Using Additives to Enhance Electrospray Ionization 1524.6.2 Additives for APCI 1534.6.3 Summary 1544.7 Tip Number 6 1544.7.1 How Can I Enhance Sensitivity of Detection? 1544.8 Tip Number 7 1554.8.1 No Linear Response and Poor Dynamic Range? 1554.8.2 The Reasons 1564.8.3 Possible Solutions 1564.8.4 Summary 1574.9 Tip Number 8 1574.9.1 HowMuch MSn Do I Need? 1574.9.2 Solutions 1584.9.3 Summary 1584.10 Need More Help? 166References 167Part III User Reports 1695 LC Coupled to MS – a User Report 171A.Muller and A. HofmannReferences 1766 ProblemSolvingwithHPLC/MS– aPracticalViewfromPractitioners 177E. Fleischer6.1 Introduction and Scope 1776.2 Case Example 1 1816.2.1 Investigation ofMethohexital Impurities and Decomposition Products 1816.2.2 Sample Preparation 1816.3 Case Example 2 1836.3.1 Separation of Oligomers from Caprolactam, Multicomponent Separation of Impurities on a Gram Scale 1836.4 Case Example 3 1846.4.1 Preparation and Isolation of bis-Nalbuphine from Nalbuphine 1846.5 Case Example 4 1866.5.1 Isolation and Elucidation of Dopamine Impurities 1867 LC/MS from the Perspective of a Maintenance Engineer 189O.Muller7.1 Introduction and Historical Summary 1897.2 Spray Techniques 1907.3 Passage Through the Ion Path 1917.4 The Analyzer 1917.5 Maintenance 193References 198Part IV Vendor’s Reports 2018 LC/MS – the Past, Present, and Future 203T.L. Sheehan and F. Mandel9 Vendor’s Report – SCIEX 207D. Schleuder10 Manufacturer Report – Thermo Fisher Scientific 213M.M. Martin10.1 Liquid Chromatography for LC/MS 21410.2 Mass Spectrometry for LC/MS 21510.3 Integrated LC/MS Solutions 21710.4 Software 217References 219About the Authors 221Index 227