6 9 The significant role of trace elements present at the Jlgfg (10- gig), ngfg (10- gig) 12 and pgfg (10- gig) levels in geological, biological, environmental and industrial materials has increasingly been recognized in science and technology. To detect and determine trace elements, we usually use modern optical, electrochemical and nuclear analytical techniques. Althouih most of them are highly sensitive and selective, preliminary enrichment techniques are required to extend the detection limits, improve precision and accuracy of analytical results, and to widen the scope of the determina tion techniques. About two decades ago, I wrote a chapter "Separations and Pre concentrations" in "Trace Analysis: Physical Methods" edited by Prof. G. H. Morrison (Wiley-Interscience, New York, 1965). Since then, the progress in this field has been remarkable. This 'monograph is intended as a laboratory book directly applicable to the practice, but is not a so-called "cookbook" which offers detailed laboratory instruc is useful for all analysts solving problems in inorganic trace tions. I hope this book analysis and appreciating the applicability and limitations of enrichment techniques combined with instrumental determination techniques. In three introductory chapters, general aspects and control of contamination and loss are discussed. The following eight chapters deal with enrichment techniques based on volatilization, liquid-liquid extraction, selective dissolution, precipitation, electrochemical deposition and dissolution, sorption, ion exchange, liquid chromato graphy, flotation, freezing and zone melting. The final two chapters are devoted to special enrichment techniques used in trace analyses of natural waters and gaseous samples.
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Verlagsort
Verlagsgruppe
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ISBN-13
978-3-540-12051-3 (9783540120513)
DOI
10.1007/978-3-642-68854-6
Schweitzer Klassifikation
1 Introduction.- 1.1 Inorganic Trace Analysis in Science and Technology.- 1.2 The Role of Enrichment Techniques in Inorganic Trace Analysis.- 2 General Aspects of Enrichment Techniques.- 2.1 Trace Recovery.- 2.2 Enrichment Factor.- 2.3 Contamination.- 2.4 Simplicity and Rapidity.- 2.5 Sample Size.- 3 Control of Contamination and Loss.- 3.1 Airborne Contamination.- 3.1.1 Clean Rooms.- 3.1.2 Clean Hoods or Benches.- 3.1.3 Other Means to Reduce Airborne Contamination.- 3.2 Contamination and Loss Due to Apparatus.- 3.2.1 Selection of Materials.- 3.2.2 Surface Treatment.- 3.2.3 Cleaning of Containers.- 3.3 Contamination Due to Reagents.- 3.3.1 Selection of Commercial Reagents.- 3.3.2 Preparation of High-Purity Reagents in Analytical Laboratories.- 3.4 Other Sources of Contamination and Loss.- 4 Volatilization.- 4.1 Volatilization from Solutions.- 4.1.1 Volatilization of Trace Elements from Solutions.- 4.1.2 Volatilization of the Matrix from Solutions.- 4.2 Volatilization from Solid and Molten States.- 4.2.1 Volatilization of Trace Elements from Solid and Molten States.- 4.2.2 Volatilization of the Matrix from Solid and Molten States.- 5 Liquid-Liquid Extraction.- 5.1 General Procedures.- 5.1.1 Batch Extraction.- 5.1.2 Continuous Extraction.- 5.1.3 Countercurrent and Chromatographic Extractions.- 5.1.4 Backwashing.- 5.1.5 Stripping.- 5.2 Extraction of Metal Chelates.- 5.2.1 Chelate Extraction Systems.- 5.2.2 Equilibria in Chelate Extraction Systems.- 5.2.3 Masking.- 5.2.4 Synergism.- 5.2.5 Coextraction.- 5.2.6 Extraction Rate.- 5.2.7 Chelate Extraction of Trace Elements.- 5.2.8 Chelate Extraction of Matrix Elements.- 5.3 Extraction of Ion Pairs.- 5.3.1 Ion-Association Systems.- 5.3.2 Ion-Association Extraction of Trace Elements.- 5.3.3 Ion-Association Extraction of Matrix Elements.- 5.4 Special Extractions.- 5.4.1 Three-Phase Extraction.- 5.4.2 Homogeneous Extraction.- 5.4.3 Extraction with Molten Organic Compounds.- 5.4.4 Extraction of Trace Elements from Nonaqueous Samples.- 6 Selective Dissolution.- 6.1 Selective Dissolution of the Matrix.- 6.2 Selective Dissolution of Trace Elements.- 7 Precipitation.- 7.1 Precipitation of Matrix Elements.- 7.1.1 Coprecipitation Phenomena.- 7.1.2 Application of Matrix Precipitation.- 7.2 Precipitation of Trace Elements.- 7.2.1 Carrier Precipitation.- 7.2.2 Application of Carrier Precipitation.- 8 Electrochemical Deposition and Dissolution.- 8.1 Electrodeposition on Solid Electrodes.- 8.2 Electrodeposition on Mercury Cathodes.- 8.2.1 Deposition of Trace Elements.- 8.2.2 Deposition of Matrix Elements.- 8.3 Spontaneous Electrochemical Deposition.- 8.4 Anodic Dissolution.- 9 Sorption, Ion Exchange and Liquid Chromatography.- 9.1 General Procedures.- 9.1.1 Batch Operation.- 9.1.2 Filtration through a Permeable SorbentDisk.- 9.1.3 Column Operation and Chromatography.- 9.2 Separation with Ion Exchange Resins.- 9.2.1 Ion Exchange Resins.- 9.2.2 Ion Exchange Reactions and Equilibria.- 9.2.3 Sorption of Trace Elements on Ion Exchange Resins.- 9.2.4 Removal of Matrix Elements by Sorption on Ion Exchange Resins.- 9.2.5 Sorption of Matrix and Trace Elements on Ion Exchange Resins Followed by Chromatographie Elution.- 9.3 Separation with Cellulosic Exchangers.- 9.4 Separation with Polyurethane Foams.- 9.5 Separation with Miscellaneous Organic Sorbents.- 9.6 Separation with Activated Carbon.- 9.7 Inorganic Ion Exchangers.- 10 Flotation.- 10.1 General Procedures.- 10.2 Carrier Precipitation Followed by Flotation.- 10.2.1 Important Experimental Factors.- 10.2.2 Applications.- 10.3 Ion Flotation.- 10.3.1 Important Experimental Factors.- 10.3.2 Applications.- 11 Freezing and Zone Melting.- 11.1 Freeze Concentration of Dilute Aqueous Solutions.- 11.2 Enrichment of Impurities in Solids by Zone Melting.- 12 Enrichment Techniques in Water Analysis.- 12.1 Separation Based on the Particle Size and Density.- 12.1.1 Filtration and Ultrafiltration.- 12.1.2 Dialysis.- 12.1.3 Gel Filtration.- 12.1.4 Centrifugation.- 12.2 Separation Based on Chemical Reactivity.- 12.2.1 Volatilization.- 12.2.2 Liquid-Liquid Extraction.- 12.2.3 Carrier Precipitation.- 12.2.4 Electrodeposition.- 12.2.5 Sorption, Ion Exchange and Liquid Chromatography.- 13 Enrichment Techniques in Gas Analysis.- 13.1 Separation of Particles.- 13.2 Separation of Gaseous Trace Constituents.- Literature.- A.1 Solvents.- A.2 Masking Agents.- A.3 Ion Exchange Data.- Index of Abbreviations and Symbols.
