Ion-Pair Chromatography and Related Techniques

Ion-Pair Chromatography (IPC) is a rapidly evolving method for difficult analyses of organic and inorganic ions and ionogenic, neutral, and zwitterionic compounds. The possibilities for this technology continue to grow as novel ion-pair reagents and strategies are introduced at an accelerated level. Compensating for a dearth in the literature, Ion-Pair Chromatography and Related Techniques details the basics and the evolution of this established and easily tunable technique and explains its influence on similar methods.

Theoretical modeling to application
Providing a thorough exploration of the multiplicity of interactions involved in an IPC system, this book emphasizes the progress from theoretical modeling to application. It explores the practical potential of IPC in the life science, medicine, pharmacology, forensic, food, and environmental sectors. It examines the upgrade of column technology and instrumentation to improve data quality and to increase sample throughput. The book also compares IPC to other instrumental methods of analysis and discusses the rising importance of the ion-pair concept in different analytical techniques.

Future endeavors
IPC has the potential to have lasting impact in the field of chromatography. Distilling the knowledge gained from preeminent research, this volume is a critical resource that is destined to stimulate future endeavors by separation scientists working in the area of high performance liquid chromatography.

Teresa Cecchi earned a Ph.D. in chemistry from Camerino University in Italy in 1997. She focused on environmental chemistry at Institute Fresenius Gruppe, Germany and served as a consultant to food chemistry laboratories. After working as a researcher at Camerino University on the SUPREME project titled "Pigmentation in South American Camelids," she concentrated on ion pairing chromatography; her major research interests encompass many aspects of this technique including retention modeling, unusual analytes such as zwitterions, and application of this technique to non-separative functions. Dr. Cecchi’s career and studies also span the fields of food packaging chemistry, natural dyes, electrochemistry, and the antioxidant activities of nutraceuticals. She acted as the organizer of a research group at Istituto Tecnico Industriale Statale (It is) Montani in Italy and taught as a contract professor at La Sapienza University in Rome. She is currently a contract professor on the Faculty of Science and Technology at Camerino University, teaching master’s level courses in chemistry and advanced chemical methodologies and a professor of analytical chemistry at ITIS Montani. Dr. Cecchi is also involved in "Teaching of Experimental Sciences" and "Scientific Master Degrees," two projects whose purposes are, respectively, to improve the methodologies of teaching physical sciences, and to encourage students to study scientific subjects. She is the author of over 50 research articles, reviews, congress lectures, and other communications and was the corresponding author of an article that received an award from the Italian Research Evaluation Panel.

Introduction
Electrolyte Solutions and Historical Concept of Ion-Pairing
Phenomenological Treatment
Ion–Solvent Interactions
Ion–Ion Aspecific Interactions
Interactions of Ions with Non-Electrolytes
Critical Review of History of Theoretical Treatments of Ion-Pairing
Thermodynamic Properties of Ion-Pairs
Techniques for Studying Ion Pairing
Retention Modeling as Function of Mobile Phase Composition
Theoretical Models of Ion-Pair Chromatography (IPC)
Empirical Models of IPC
Modeling of Retention as a Function of Analyte Nature
Stationary Phases
Reversed Phase IPC
Normal Phase IPC and Other Stationary Phases
Developments in Column Technology and Fast IPC
Ultrahigh Performance Liquid Chromatography (U-HPLC)
Monolithic Columns
Ion-Pair Reagents
Traditional IPRs
Volatile IPRs
Chaotropic Salts
Ionic Liquid-Based IPRs
Unusual IPRs
IPR Counter Ions
Organic Modifiers
Organic Modifier Concentration in Eluent
Nature of Organic Modifier
Gradient Elution
Role of Eluent pH in IPC
IPC versus RP-HPLC
pH-Dependent Silanol Ionization
Temperature
Influence of Temperature on Column Efficiency
Influence of Temperature on Selectivity under RP-HPLC and IPC Conditions
Special IPC Modes and Variations
Mixture of Different IPRs in Mobile Phase
Permanently Coated Columns
IPRs Added Only to Sample Solution and Ghost Peaks
Special Additives in Mobile Phase
Modification of Eluent Ionic Strength at Constant IPR Concentration
Detection and Combination
UV-Vis Detectors
Fluorescence Detectors
Electrical Conductivity Detectors
Electrochemical Detectors
Evaporative Light Scattering Detectors
Unusual Detectors
Hyphenated Techniques
Examples of Applications
Inorganic and Organometallic Species
Food Analysis
Life Science and Medicine
Pharmaceutical, Toxicological and Clinical Analysis
Environmental Analysis
Enantiomeric Separations
IPC versus Competitive Techniques
Ion-Pairing in Different Analytical Techniques
Capillary Electrophoresis (CE) and Related Techniques
Supercritical Fluid Chromatography (SFC) and Other Techniques
UV-Visible Spectrophotometry
Extraction and Sample Preparation
Non-Separative Applications of IPC
Conclusions and Future Research Needs