Ultrasound in Chemistry

"The book can be recommended to practicing analytical chemists who need to develop more efficient strategies for analysis, and in general to those practitioners who need to improve analytical methodological performance. It could also serve as a valuable starting point for researching new avenues in the analytical use of ultrasound." (Anal Bioanal Chem, 2009) "Analytical Applications is a practical book that emphasizes some of the latest developments in the implementation of ultrasound in the analytical lab." (Analytical and Bioanalytical Chemistry, August 2009)

J. L. Capelo-Martnez obtained his PhD in chemistry in 2002 from the University of Vigo, Spain, where he was associate professor from 1999 to 2002. In December 2004 he became Research Fellow at the Associated Laboratory REQUIMTE, as well as at the Chemistry Department of the New University of Lisbon, and in 2006 was invited as an auxiliary professor to the same institution. His research work is related to new uses of ultrasonic energy as a tool at the Analytical Chemistry Laboratory. Dr. Capelo has more than fifty manuscripts and several patents to his name, he is a regular referee for various analytical journals and a member of the advisory board of the Analytical Journal TALANTA.

Preface XI List of Contributors XIII 1 The Power of Ultrasound 1 Hugo Miguel Santos, Carlos Lodeiro, and Jos-Luis Capelo-Martnez 1.1 Introduction 1 1.2 Cavitation 1 1.2.1 Parameters Affecting Ultrasonic Cavitation 3 1.2.1.1 Frequency 3 1.2.1.2 Intensity 4 1.2.1.3 Solvent 5 1.2.1.4 Temperature 5 1.2.1.5 External Pressure and Bubbled Gas 5 1.2.1.6 Direct and Indirect Ultrasonic Application 6 1.3 Common Ultrasonic Devices Used in Analytical Chemistry 6 1.3.1 Ultrasonic Bath 6 1.3.1.1 Types of Ultrasonic Baths 7 1.3.1.2 How to Locate the Most Efficient Place Inside an Ultrasonic Bath 8 1.3.1.3 Temperature Control 8 1.3.1.4 Shape and Material of Reaction Container 9 1.3.2 The Ultrasonic Probe 9 1.3.2.1 Parts of an Ultrasonic Probe 10 1.3.2.2 Types of Ultrasonic Probes 10 1.3.2.3 Dead Zones 11 1.3.2.4 How to Choose the Correct Ultrasonic Probe 12 1.3.2.5 Temperature Control 13 1.3.2.6 Shape and Material of Reaction Container 14 1.4 Current Ultrasonic Devices for New Analytical Applications 14 References 15 2 Ultrasonic Energy as a Tool for Sample Treatment for the Analysis of Elements and Elemental Speciation 17 Hugo Miguel Santos, Carlos Lodeiro, and Jos-Luis Capelo-Martnez 2.1 Introduction 17 2.2 Parameters Influencing Element Ultrasonic SolidLiquid Extraction 17 2.2.1 Extracting Reagent 17 2.2.1.1 Extracting Reagents for Total Element Extraction 18 2.2.1.2 Extracting Reagents for Elemental Speciation 19 2.2.1.3 Extracting Reagents for Sequential Extraction Schemes 19 2.2.2 Matrix Properties 20 2.2.2.1 Type of Matrix 20 2.2.2.2 Mass of Matrix 20 2.2.2.3 Sample Size 22 2.2.3 Ultrasonic Device 22 2.2.3.1 Type of Ultrasonic Device 22 2.2.3.2 Time of Ultrasonication 23 2.2.3.3 Ultrasonic Amplitude 23 2.2.3.4 Ultrasonic Frequency 23 2.2.3.5 Temperature of Sonication 23 2.3 US-SLE from Soils and Sediments 24 2.4 US-SLE from Sewage Sludge 24 2.5 US-SLE Extraction from Plants 24 2.6 Extraction from Soft Tissues 27 2.7 Total Element Determination 27 2.7.1 US-SLE and US-SS for F-AAS 27 2.7.2 US-SLE and US-SS for ET-AAS 28 2.7.3 US-SLE and US-SS for CV and HG Employed with AAS or AFS 28 2.8 Elemental Fractionation and Elemental Speciation 30 2.8.1 What is Speciation? 30 2.8.2 Shortening Sequential Fractionation Schemes 31 2.8.3 Speciation for Soils and Sediments 34 2.8.4 Speciation from Plants 34 2.8.5 Speciation from Soft Tissues 36 2.8.6 Speciation from Other Types of Samples 43 2.9 On-Line Applications 45 2.9.1 Open and Closed Systems 46 2.9.2 UB 47 2.9.3 UP 47 2.10 Current Trends 48 2.10.1 Accelerating LiquidLiquid Extractions 48 2.10.2 Chemical Vapor Formation 49 2.11 Conclusion 49 References 50 3 Ultrasonic Assisted Extraction for the Analysis of Organic Compounds by Chromatographic Techniques 55 Raquel Rial-Otero 3.1 Introduction 55 3.2 Overview of Classic and Modern Extraction Procedures for Organics 56 3.3 Ultrasonic Assisted Extraction (UAE) 60 3.3.1 Basic Principles 60 3.3.2 Parameters Influencing Ultrasonic Assisted Extraction 61 3.3.2.1 Amount of Sample 61 3.3.2.2 Sample Particle Size 61 3.3.2.3 Extraction Solvent 61 3.3.2.4 pH of Extracting Solution 62 3.3.2.5 Solvent Volume 62 3.3.2.6 Sonic Power 62 3.3.2.7 Frequency 63 3.3.2.8 Extraction Time 63 3.3.2.9 Extraction Temperature 63 3.3.3 Applications 63 3.3.3.1 Liquid Samples 64 3.3.3.2 Solid Samples 64 3.3.3.3 Clean-Up 70 3.4 Coupling Ultrasound with Other Extraction Techniques 71 3.4.1 Coupling Solid Phase Microextraction (SPME) and Ultrasound 71 3.4.1.1 Improving the Extraction Procedure in Direct-SPME 71 3.4.1.2 Improving the Extraction Procedure in HS-SPME 73 3.4.1.3 Facilitating the Desorption Process 73 3.4.2 Coupling Stir Bar Sorptive Extraction (SBSE) and Ultrasound 74 3.5 Comparison between UAE and Other Extraction Techniques 75 3.6 Conclusion 76 References 77 4 Elec