9. Atomic Flame Emission Spectroscopy (Flame Photometry)
Introduction
Principles of Flame Photometry
Instrumentation for Atomic Emission Spectrometry
Methods for introducing the sample into the flame, nebulization, hydride generation technique, aspiration of solid samples, direct sample insertion, Atomization by a flame, flames, burners (as flame atomizers), Optical system, Photodetectors, Recorders/readout meters
Sample Preparation
Flame Photometers
Single-beam, Double-beam
Flame Emission Spectrometry
Optimization of Flame Processes
Interferences in Flame Photometry
Spectral interference, Background corrections, Ionization interference, Self-absorption, Physical interference
Experimental Procedure for Quantitative Analysis
Calibration curve procedure, Standard addition procedure, Internal standard procedure
Applications of Flame Emission Spectroscopy
Determinations by Flame Emission spectrometry
10 Atomic Flame Absorption Spectroscopy [AAS]
Introduction
Principles of Atomic Absorption Spectroscopy
Linewidth Effects and Absorption Characteristics
Atomic Absorption Instrumentation
Hollow cathode lamps, Electrodeless discharge lamps, Modultion of the source, Sample vaporization, flame vapourization, flameless vapourization, graphite tube furnace, carbon rod or filament, Vapourization by reduction (generation of a hydride)
Spectrophotometers for AAS
Single beam, 309; Double beam
Applications of Atomic Absorption Spectrometry
Relative Detection Limits of AAS and FES
Experimental Section
Determination of Ca2+ by AAS
Determination of Ca2+ by AAS in an unknown solution
Determination of Na+ by FES
Determination of Na+, K+ and Ca2+ (in mineral waters) by FES
11 Mass Spectrometry
Introduction
Design and Sample Flow in a Mass Spectrometer
Molecular Mass Spectra (Cleavage Reactions and Molecular Ion)
Sample Size and its Placement
Vacuum Creation
Sample Inlet Systems
Ion Sources (Ionization Chamber)
Electron impact ionization sources, Chemical ionization sources, Field ionization
Mass Analysers
Single focussing magnetic sector analysers, Double focussing mass spectrometers, Qudrupole mass spectrometers, Time-of flight mass analysers, Fourier-transform-ion cyclotron resonance analyser
Detection and Recording
Resolution
Fragmentation Process
Identification by Fragmentation
Determination of Molecular Formulae
Molecular Ion
Atomic Weights in Mass spectrometry
Determination of Natural Abundance of the Isotopes
Example
Representation of Some Simple Mass Spectra
Metastable Ions
Applications of Molecular Mass Spectrometry
Advantages of the Mass spectrometry
ElectroAnalytical Techniques
12 Introduction to Electrochemistry
Introduction
Oxidation and Reduction Reactions
Oxidation State (or Number)
Galvanic Cells and Half-Reaction Concept
Liquid Junction Potential and its Elimination
Single Electrode Potential (Double Layer Concept)
Balancing Redox Reactions
Electrode Potential and Standard Electrode Potential
More About Sign Conventions
Effect of Concentration on Electrode Potentials (Nernst's Equation)
Formal Potentials
Redox Indicators
Principles Involved in Redox Titrations
Equilibrium constant and feasibility of redox reactions, Representation of a titration curve for a redox system, Some oxidants as titrants
Electrochemical Cells with Significant Currents
Ohmic potential (IR drop), Polarization, Overvoltage (activation overpotential), Concentration overvoltage or concentration polarization
13 Potentiometric Measurements
Introduction
Principles of the Potentiometry
Accuracy in Potentiometric Methods
Advantages of the Potentiometric Methods
Reversible Electrodes
Electrodes of the first type (or electrodes reversible with respect to cations), metal-metal ion electrodes, amalgam electrodes, gas electrodes, Electrodes of the second type (or electrodes reversible with respect to anions, calomel electrode, silver-silver chloride electrode, gas electrode, Electrodes of the third type, Electrodes of the fourth type (or Redox electrodes)
Standard (or Normal) Hydrogen Electrode (SHE or NHE)
Hildebrand bell-type, Lindsey type, advantages, disadvantages
Calomel Electrode
Silver-Silver Chloride Electrode
Indicater Electrodes
Metal-metal ion electrode, electrodes of the first type, electrodes of the second type, electrodes of the third type, inert (or redox) metal electrodes, Membrane electrodes, glass electrode, merits, demerits, precautions in use
Measurement of the Cell EMF with a Potentiometer
Principle of potentiometer, Standard (Weston) cell, Potentiometers
Potentiometric Measurement of pH and pH Meter
With hydrogen electrode, 402; using Quinhydrone electrode, 403; Glass-membrane electrode, 405; Antimony-antimony oxide electrode
Operational Definition of pH
Measurement of pH with a pH Meter
Potentiometric Titrations
Principal Types of Potentiometric Titrations
Acid-base (or neutralization) titrations, 414; Precipitation titrations, 415; Redox titrations, 416; Complex-formation titrations
Null-Point Potentiometry
Dead-Stop End Point Potentiometry
Applications of Potentiometry and Potentiometric Titrations
Some Acid-Base and Redox Determinations
Determination of Ka of a weak acid, Determination of Fe(II) with KMnO4, Determination of the strength of K2Cr2O7 against Fe(II)
14. Conductometric Titrations
Introduction to Electrical Conductance
Specific conductance, Equivalent conductance, Relation between specific and equivalent conductances, Molar conductance
Variation of Molar Conductance with Dilution
Degree of Dissociation of a Weak Electrolyte
Kohlrausch's Law
Ostwald's Dilution Law
Conductivity Cells and Cell Constant
Conductivity Water
Platinization of Platinum Electrodes
Determination of Cell Constant
Measurement of the Conductivity Using Kohlrausch Wheatstone Bridge
Applications of Conductance Measurements
Determination of degree of dissociation, Ionic product of water, Solubilities and solubility products, Conductometric titrations
Conductometric Titrations, 441
Some typical titrations, strong acid-base titration, strong acid-weak base, weak acid-strong base, very weak acid with a strong base, weak acid-weak base, mixture of a strong and weak acids with a strong base, displacement (or replacement), Precipitation titrations, Advantages
Oscillometry (High Frequency Titrations)
Applications
15 Voltammetry and Polarographic Methods
Introduction
Excitation Signal
Voltammetric Cell
Polarography
Dropping mercury electrode (DME), merits, demerits, its handling (precautions), Experimental details, Procedure, Circuit of a simple manual polarograph, Miscellaneous phenomena at the DME
Current-Voltage Curve (Basis of Polarography)
Ilkovic Equation
Residual Currents
Half-Wave Potentials
Polarographic Maxima
Quantitiative Evaluation of a Polarographic Wave
Exact procedure, Approximate procedure, Graphical method
Polarographic Methods of Analysis
Direct comparison method, Internal standard (or pilot ion method), Standard addition method
Organic Polarographic Analysis
Applications of Polarography
Inorganic applications, Analysis of mixtures, Determination of stability constant of complexes, Organic applications
Comparison of Polarography and Amperometry
16 Amperometry
Introduction
Types of Amperometric Titration Curves
Volume Changes
Advantages of Amperometric Titrations
Disadvantages
Instrumentation
Amperometric titrations with DME, Lingane and Laitinen cells
Rotating Platinum Microelectrode
Applications of Amperometric Titrations
Determination of Ni2+ with DMG (amperochelometry)
Successive determination of Cl–, Br– and I–
Biamperometric (Using Two Indicator Electrodes) Titrations
Water (Moisture) Determination by Amperometry
17 Coulometry
Introduction
Controlled-Potential Coulometry
Instrumentation, Applications
Amperostatic Coulometry (Coulometric Titrimetry)
Titration cell, 496; principles, 497; End point detection
Instrumentation
Advatnages of Coulometric Titrations
Errors in Coulometric Titrations
Applications
Neutralization titrations, Precipitation and complex formation titrations, Oxidation-reduction titrations
Coulometric Titration of Cyclohexene with Bromine
APPENDICES |
I | List of Analytical Abbreviations |
II | Symbols, Conversion Factors, and Prefixes |
III | Use of Logarithm |
IV | Molar Masses of Some Compounds |
V | pH Indicators |
VI | Density of Solutions |
VII | Solubility Product Constants |
VIII | Tables Related to Specific and Equivalent Conductances |
IX | Some Standard and Formal Reduction Electrode Potentials |
X | Common Chromophores : Electronic Absorption Characteristics |
XI | Characteristic Infrared Absorption Bands |
XII | Resonance Lines for Atomic Absorption |
XIII | Polarographic Half-Wave Potentials |
XIV | A Comparison of Trace Element Detection Limits by FES and FAAS |
XIV | -A Dissociation Constants of Some Acids in Water at 25°C |
-B Acidic Dissociation Constants of Some Bases in Water at 25°C |