Polymer-Based Aqueous-Two Phase Systems: Fundamentals and Applications

Description

This book presents the fundamentals of the separation mechanism of the environmentally benign polymer-based aqueous two-phase systems (ATPS) and applications of ATPS to separation and/or enrichment of inorganic compounds with batch extraction and chromatographic techniques. It first describes the structures of the aqueous polymer phases formed in the ATPS. Then the effect of the background electrolyte on the distribution of ionic solutes is discussed. A subsequent chapter shows the applications of the ATPS batch extraction to analyses of trace metal ions in environmental samples. In the following chapter, the author introduces multistep pH-peak-focusing countercurrent chromatography developed for the separation and enrichment of metal ions with a PEG/Na2SO4 ATPS. Lastly, the author explains that liquid chromatography (LC) with hydrophilic polymer gel columns using an aqueous solution as the mobile phase is regarded as an efficient separation and enrichment technique based on ATPS, and describes multi-step pH peak focusing LC and partition/ion-exclusion chromatographic ion stacking (PIEC ion stacking), newly developed ATPS chromatographic techniques for separation and enrichment of metal ions and inorganic anions in detail. This book helps researchers and engineers design and implement appropriate environmentally benign analytical methods for environmental analyses, reagent manufacturers, metal refining industry, and so on. Cover Half Title Polymer-Based Aqueous-Two Phase Systems: Fundamentals and Applications Copyright Preface Contents 1. Introduction to Extraction and Chromatography with Polymer-Based Aqueous-Two Phase Systems 1.1 Background 1.2 Phase Diagram 1.3 Structures and Properties of the Aqueous Polyethylene Glycol Phases as Extraction Media in ATPS 1.4 Effects of the Background Phase-Forming Electrolytes on the Partition of Ionic Solutes in PEG/Salt ATPS 1.5 Trace Analyses of Metal Ions in Environmental Samples Based on the Separation and Preconcentration by Extraction with ATPS 1.6 Multistep pH-Peak-Focusing Countercurrent Chromatography 1.7 Aqueous Liquid Chromatography with Hydrophilic Polymer Gel Columns 1.8 ATPS Chromatographic Techniques for Separation and Enrichment of Metal Ions and Inorganic Anions: Multistep pH-Peak-Focusing Liquid Chromatography and Partition/Ion-Exclusion Chromatographic Ion Stacking References 2. Structures and Properties of the Aqueous Polyethylene Glycol Phases as Extraction Media in ATPS 2.1 Introduction 2.2 Complexation Reactions of Co(II) with Thiocyanate Ion in Aqueous PEG Solutions 2.3 Effect of Terminal Functional Groups of Ethylene Oxide Chains on the Formation of Co(II) Thiocyanate Complexes 2.4 A Micro-Heterogeneous Structure Model of PEG–Water Mixtures 2.5 Thermal Phase Transition Behavior of Water in Aqueous PEG Solutions 2.6 Conclusions References 3. Effects of the Background Phase-Forming Electrolytes on the Partition of Ionic Solutes in PEG/Salt ATPS 3.1 Introduction 3.2 Effects of the Phase-Forming Salt on the Phase Diagram of PEG/Salt ATPS 3.3 Intrinsic Effect of the Background Phase-Forming Ions on the Distribution of Ionic Solutes in PEG/Salt ATPS 3.4 Conclusions References 4. Trace Analyses of Metal Ions in Environmental Samples Based on the Separation and Preconcentration by Extraction with ATPS 4.1 Introduction 4.2 Distribution Mechanism of Metal Ions by Complexation with Inorganic Anions 4.3 Spectrophotometric Determination of Trace Amounts of Cadmium in Soil and Sediment Samples 4.3.1 Extraction of Cd(II) with Iodide Ion in PEG6000/Na2SO4 ATPS 4.3.2 Selective Extraction of Cd(II) in a Soil Sample 4.3.3 Enhancement of Selectivity of Extraction and Chromogenic Reaction of Cd(II) Using Masking Reagents 4.3.4 Determination of Cd(II) in Soil and Sediment Samples 4.4 Spectrophotometric Determination of Trace Amounts of Zinc in Environmental Water 4.4.1 Fast Phase Separation Using Convection 4.4.2 Effect of Thiocyanate Concentration on the Extraction of Zn(II) 4.4.3 Masking of Foreign Metal Ions for Selective Spectrophotometric Determination of Zn(II) 4.4.4 Determination of Zn(II) in Tap Water and River Water Samples 4.5 Conclusions References 5. Multistep pH-Peak-Focusing Countercurrent Chromatography 5.1 Introduction 5.2 Effect of the Operating Conditions on the Separation Performance of CCC 5.3 Extraction of Rare Earth Elements with Acetylacetone in PEG/Na2SO4 ATPS 5.4 pH Profile of the Column Effluent Formed by pH Stepwise Elution with Buffer Solutions 5.5 Simultaneous Separation and Enrichment of Rare Earth Elements by Multistep pH-Peak-Focusing CCC 5.6 Conclusions References 6. Aqueous Liquid Chromatography with Hydrophilic Polymer Gel Columns 6.1 Introduction 6.2 Liquid Chromatographic Determination of the Amounts of Water Acting as a Component of the Separation Media in Hydrophilic Polymer Gels 6.3 Thermal Phase Transition Behavior of Water Sorbed in Hydrophilic Polymer Gels 6.4 Solute Retention Selectivity of Hydrophilic Polymer Gel Columns 6.5 Conclusions References 7. ATPS Chromatographic Techniques for Separation and Enrichment of Metal Ions and Inorganic Anions: Multistep pH-Peak-Focusing Liquid Chromatography and Partition/Ion-Exclusion Chromatographic Ion Stacking 7.1 Introduction 7.2 Multistep pH-Peak-Focusing Liquid Chromatography 7.2.1 Retention Behavior of Rare Earth Elements on a Hydrophilic Polymer Gel Column with Aqueous Mobile Phases Containing Acetylacetone 7.2.2 Effect of pH-Peak-Focusing on the Elution Peak of a Rare Earth Element in ATPS-LC 7.2.3 Synergistic Effect of 1,10-Phenanthroline on the Retention of Rare Earth Elements with Acetylacetone 7.2.4 Multistep pH-Peak-Focusing Separation of Rare Earth Elements by ATPS-LC 7.3 Partition/Ion-Exclusion Chromatographic Ion Stacking 7.3.1 Mechanism of Ion Stacking in the Process of Partition Chromatography 7.3.2 Stacking Behavior of Inorganic Anions in Migration Through an Octadecyl-Bonded Silica Column 7.3.3 Ion Stacking by a Combination of Partition and Ion Exclusion with a Hydrophilic Polymer Gel Column 7.3.4 Analysis of Trace Amounts of Anions in Salt Samples by Online PIEC Ion Stacking-Ion Chromatography 7.4 Conclusions References