The Art and Science of Chemical Analysis

by Christie G. Enke (Univ. of New Mexico, Albuquerque)

• ISBN13: 9780471373698
• ISBN10: 0471373699
• Edition: 1
• Format: Hardcover
• Copyright: 2000-12-01
• Publisher: Wiley

Summary

Graphs and Excel-based problems appear throughout the book and are supported by user-friendly templates on the accompanying CD. * Study questions and problems appear every few pages throughout the book. These questions are followed by answers. * Enke's book is organized by differentiating characteristics rather than by techniques.

Author Biography

<b>Chris Enke's</b> first book was "Electronics for Scientists" written with Howard Malmstadt, and in later versions with Stan Crouch as well. This book is the ninth he has authored or coauthored. Between these "bookends" he has been active in research and teaching. He is currently Professor of Chemistry at The University of New Mexico and Professor Emeritus at Michigan State University. His Ph.D. was earned at the University of Illinois. He has mentored over 60 Ph.D. students whose theses are in the areas of electroanalytical chemistry, computer-based instrumentation, optical spectroscopy, and mass spectrometry. Over 150 papers and book chapters have resulted from this research. He has received American Chemical Society awards in Chemical Instrumentation and Computers in Chemistry, the Distinguished Faculty Award at Michagan State University, and is an AAAS Fellow. Among his several inventions is the triple quadrupole mass spectrometer (with Rick Yost) for which they received the Distinguished Contribution Award from the American Society for Mass Spectrometry. Chris has served as President of ASMS, Chairman of the Computers in Chemistry Division of ACS, and has been a member of many professional society and journal advisory boards. Thus present book was written out of his love for the subject of analytical chemistry and in appreciation of congenial colleagues, stimulating students, and rewarding research.

Table of Contents

Chemical Analysis, What, Who, and Why	1	(14)
Chemical Quantities	2	(2)
Units Involved in the Expression of Amount	2	(2)
The Differentiating Characteristic	4	(2)
Devising a Probe for the Differentiating Characteristic	4	(1)
Anticipating the Response to the Probe	5	(1)
Measuring the Response to the Probe	5	(1)
Quantitation	6	(1)
Assessing Errors and Interferences	6	(1)
Detection	7	(1)
Assessing Confidence in the Results	7	(1)
Identification	8	(2)
Identification by Deductive Reasoning	9	(1)
``Analyze This for Me!''	9	(1)
Separation	10	(2)
Single-Step Separation	10	(1)
Separation by Dispersion	11	(1)
Chemical Analysis in Science and Society	12	(3)
Challenges and Rewards	12	(1)
The Evolution of Chemical Analysis	12	(1)
Practice Questions and Problems	13	(2)
The Elements of Measurement	15	(46)
Measurement, Interpretation, and Observation	15	(3)
Measurements and Interpretations	16	(1)
Information from Sets of Measurement Data	16	(1)
Sources of Measurement Numbers	16	(1)
Measurement Qualities	16	(2)
Elements of Measurement Systems	18	(2)
Conversion Devices	18	(1)
Input/Output Relationships	19	(1)
Examples of Measurement Systems	20	(4)
The Analog Thermometer	20	(1)
The Ammeter	20	(2)
The Analog Clock	22	(1)
pH Paper	23	(1)
Characteristics of Scalar Readouts	24	(2)
Linear Scales	24	(1)
Scalar Readout Characteristics	25	(1)
Interpolation Errors	25	(1)
Verniers	25	(1)
Scales in Arcs or Circles	26	(1)
Volume-to-Length Converters	26	(4)
The Graduated Cylinder	27	(1)
Scale Indication by Liquid Level	27	(1)
The Buret	27	(1)
The Volumetric Flask	28	(1)
The Pipet	28	(1)
Effects of Temperature on Volumetric Measurements	28	(2)
Characteristics of Digital Readouts	30	(4)
The Number Register	30	(1)
The Stepwise form of the Transfer Function	31	(1)
Range and Resolution	31	(1)
Measurements Involving ADCs	32	(1)
The Discrete Nature of the Data	32	(1)
Stimulus---Response Measurements	33	(1)
Null Measurements and Conversion Devices	34	(5)
Double-Pan Balance	34	(1)
Null Measurement Characteristics	35	(1)
Null Conversion Devices	36	(1)
The Electronic Analytical Balance	37	(2)
Measurement Accuracy and Precision	39	(6)
Measures of Precision	39	(1)
Confidence Intervals	40	(2)
Significant Figures	42	(1)
Measurement Precision in Data Processing	42	(3)
Comparing Means and Deviations	45	(6)
Comparing the Mean with an Accepted Value	45	(1)
Comparing the Means of Two Data Sets	46	(1)
Limit of Detection	47	(1)
Comparing the Deviations of Two Data Sets	48	(1)
Rejection of Data	48	(3)
Least Squares Method for Linear Plots	51	(10)
The Straight Line	52	(1)
Linear Regression	52	(1)
Precision of the Regression Results	52	(4)
Precision of Values Calculated from the Working Curve	56	(2)
Practice Questions and Problems	58	(3)
Acidity, Activity, and pH	61	(29)
Acids, Bases, and their Reactions	61	(3)
Conjugate Acid---Base Pairs	61	(1)
Relative Strengths of Acids and Bases	62	(1)
Equilibrium Constants	62	(2)
Acids and Bases in Water	64	(6)
Reactions of Acids with Water	64	(1)
Relationship Between [H3O+] and [OH-] in Water	64	(2)
Reactions of Bases with Water	66	(1)
Logarithmic Concentration Expressions	67	(1)
Other Amphiprotic Solvents	68	(2)
Concentrations, Activities, and pH	70	(9)
Chemical Potential	70	(2)
Chemical Activity	72	(2)
Activity Coefficients	74	(3)
Mean Ionic Activities	77	(1)
Activity Coefficients of Neutral Species	77	(2)
Equilibrium Constants	79	(5)
The Equilibrium State	80	(1)
Thermodynamic and Formal Equilibrium Constants	80	(1)
The Effect of Ionic Strength on K'a	81	(1)
Using Formal Equilibrium Constants	82	(2)
pH Electrode and the Definition of pH	84	(6)
The pH Electrode	84	(1)
pH Standards	85	(1)
The Definition of pH	85	(1)
The Measurement of pH	86	(2)
Practice Questions and Problems	88	(2)
Analysis by Acid---Base Reactivity	90	(46)
Equilibrium Concentrations	90	(5)
The Fraction of the Conjugate Pair in Each Form	91	(1)
Solving for [H3O+] in Solutions of Acids	92	(1)
Solving for [H3O+] in Solutions of Bases	93	(2)
Exact Equilibrium Expressions	95	(3)
Quantitation by Acid---Base Titration	98	(11)
Making the Standard Titrant	98	(2)
Adding Known Volumes of Standard Solution	100	(2)
Detecting the Response to the Titrant	102	(1)
Using an Indicator	103	(2)
Using a pH Meter	105	(1)
Concentration Effect in Strong Acid---Base Titration	106	(3)
Weak Acids, Weak Bases, and Buffers	109	(6)
Titration of Weak Acids	109	(2)
Buffer Solutions	111	(2)
Titration of Weak Bases	113	(2)
Logarithmic Concentration Plots	115	(9)
Constructing Logarithmic Concentration Diagrams	116	(1)
Solving Problems with Log Plots	117	(3)
Obtaining Titration Curve Points from Log Plots	120	(4)
Quantitation in Polyprotic Systems	124	(9)
Alpha Plots for Polyprotic Systems	125	(2)
Logarithmic Concentration Diagrams	127	(1)
Titration Curves in Polyprotic Systems	128	(2)
Titrations of Acid Mixtures	130	(3)
Other Analyses by Acid---Base Reaction	133	(3)
Identification by Acid---Base Reactivity	133	(1)
Detection by Acid---Base Reactivity	134	(1)
Separation by Acid-Base Reactivity	134	(1)
Practice Questions and Problems	134	(2)
Analysis by Absorption of Light	136	(46)
Colored Solutions and White Light	138	(5)
The Wave Nature of Light	139	(1)
The Particle Nature of Light	140	(1)
Sources of Light	140	(1)
Light Absorbing Solutions	141	(2)
Measuring the Absorption of Light	143	(5)
Developing the Probe	143	(2)
Anticipating the Response to the Probe	145	(1)
Detecting the Response to the Probe	145	(1)
Obtaining the Fraction of Light Transmitted	146	(2)
Relating Light Absorption to Concentration	148	(6)
Rationalizing the Working Curve	149	(1)
The Absorbance-Concentration Relationship	150	(2)
Calibration of the Working Curve	152	(2)
Instruments for Absorption Measurements	154	(7)
Photometers	154	(2)
Spectrometers	156	(1)
Flow Injection Analysis	157	(4)
The Absorbance Spectrum	161	(3)
Rationalizing the Absorbance Spectrum	161	(3)
Obtaining an Absorbance Spectrum	164	(7)
Scanning Spectrometers	164	(2)
Array Detector Spectrometers	166	(1)
Fourier Transform Spectrometers	167	(2)
Attenuated Reflectance Spectroscopy	169	(2)
Spectral Precision and Accuracy	171	(1)
Identification by the Absorption of Light	172	(4)
Compound Identification by Spectral Matching	173	(1)
Deduction of Molecular Structure and Composition	174	(2)
Separation by the Absorption of Light	176	(6)
Mixture Spectra	176	(1)
Resolution by Simultaneous Equations	176	(2)
Study Questions, Section I	178	(1)
Practice Questions and Problems	179	(3)
Analysis by Photon Emission	182	(32)
Photon Excitation of Molecular Species	183	(5)
Photon Absorption	184	(1)
Scattering of the Excitation Radiation	184	(1)
Vibrational Relaxation	185	(1)
Molecular Fluorescence	186	(1)
Phosphorescence	187	(1)
Fluorescence and Phosphorescence Spectrometry	188	(7)
Quantitation	190	(2)
Excitation and Emission Spectra	192	(2)
Phosphorescence Measurements	194	(1)
Raman Spectrometry	195	(3)
Excitation from Chemical Reactivity	198	(3)
Chemiluminescence Measurements	199	(1)
Chemiluminescence Applications	199	(2)
Thermal Excitation and Atomic Emission	201	(6)
Flame Excitation	203	(1)
Plasma Excitation	204	(2)
Creating the Aerosol	206	(1)
Photon Excitation of Atomic Species	207	(7)
Flames for use with Photon Excitation	208	(1)
Furnaces for Sample Atomization	208	(1)
Atomic Fluorescence Spectroscopy	208	(1)
Atomic Absorption Spectroscopy	209	(2)
Practice Questions and Problems	211	(3)
Analysis by Complexation Reactivity	214	(39)
Complexation Reactions	214	(2)
Bonds Formed in Complexation	215	(1)
Complexing Species	215	(1)
Reaction Rates	215	(1)
Equilibrium Concentrations	216	(7)
Formation of a 1: 1 Complex	216	(2)
Solving for Concentrations in Complexation Systems	218	(2)
Formation of Higher Order Complexes	220	(1)
Alpha Plots	220	(3)
The Effect of [H3O+] on Complex Equilibria	223	(7)
Hydrolysis of the Coordination Center	224	(1)
Hydrolysis of the Ligand	225	(2)
Hydrolysis of Ligand and Coordination Center	227	(3)
Quantitation by Complexation Titration	230	(5)
Standard Titrants	230	(1)
Titration Curves	230	(3)
Achieving Selectivity with EDTA Titrations	233	(2)
Equivalence Point Detection	235	(6)
Indicators	235	(1)
Displacement Titration	236	(1)
Back Titrations	237	(1)
Specific Ion Electrodes for Equivalence Point Detection	237	(1)
Light Absorption for Equivalence Point Detection	237	(4)
Log Concentration Plots	241	(6)
1:1 Complex Formation	241	(2)
Stepwise Complex Formation Systems	243	(1)
Prediction of Titration Curves	244	(3)
Spot Tests, Test Strips, Flow Injection Analysis, and Immunoassays	247	(6)
Spot Tests	247	(1)
Test Strips	248	(1)
Flow Injection Analysis	248	(1)
Immunoassays	249	(1)
Practice Questions and Problems	250	(3)
Analysis by Precipitation Reactivity	253	(29)
Precipitation Reactions	253	(6)
The Equilibrium Expressions	254	(1)
The Crystallization of Precipitates	255	(2)
The Nucleation of Precipitates	257	(2)
Equilibrium Concentrations	259	(3)
Simple Solubility Calculations	259	(1)
Effect of Hydrolysis on Solubility	259	(2)
Effect of Complexation on Solubility	261	(1)
Quantitation by Precipitation Titration	262	(5)
Frequently Used Reactions	243	(19)
Titration Curves	262	(3)
Equivalence Point Detection	265	(2)
Logarithmic Concentration Plots	267	(8)
Unsymmetrical Log Plots	269	(2)
Estimation of Titration Curves	271	(4)
Separation by Precipitation	275	(2)
Quantitation by Weighing the Precipitate	277	(2)
Spot Tests and Test Strips	279	(3)
Practice Questions and Problems	280	(2)
Analysis by Electrode Potential	282	(37)
Electron Exchange at Metals	282	(6)
The Equilibrium Potential Difference	283	(2)
Metal-Solution Potentials from Two Related Ionic Species	285	(3)
Calculating Redox Equilibrium Electrode Potentials	288	(5)
Formal and Thermodynamic Standard Potentials	289	(1)
Relating Redox Concentrations to Equilibrium Potentials	290	(1)
The pH Dependence of Equilibrium Potentials	290	(1)
The Hydrogen Electrode	291	(2)
Measurement of Electrode Potentials	293	(5)
The Necessity of a Reference Electrode	293	(1)
Calculating the Expected Measurement Voltage	294	(1)
Relating Electrode Voltage to Activity and Concentration	295	(1)
Electrodes of the Second Kind	296	(2)
Log Concentration Plots for Redox Couples	298	(6)
Lines for the Case Where Ox and Red are Dissolved	299	(1)
Lines for the Case Where Only Ox or Red is Dissolved	299	(1)
Lines for Secondary Reaction Species	300	(1)
Using Log Plots for Cell Equilibrium Potentials	300	(1)
Log Plots of Unsymmetrical Couples	301	(3)
Ion Reactions on Membrance Surfaces	304	(7)
H+ Reaction with a Glass Surface	305	(1)
Calculation of the Interfacial Potential	305	(1)
Measurement of Interfacial Potential	306	(1)
Use of the Measured Voltage to Calculate pH	307	(1)
Transistor Chemical Sensors	307	(1)
Interfering Electrode Reactions	308	(1)
Gas-sensing Electrodes	308	(1)
The Use of Ion-Surface Interactions for Ions Other than H+	309	(2)
Ion Diffusion Through Porous Membranes	311	(5)
Development of Electrical Potential Difference	312	(1)
Measurement of Membrane Potential	312	(1)
Electrode Types and Interferents	313	(1)
Liquid Junction Potentials	314	(1)
The Equivalence of Response Function for all Electrodes	315	(1)
Selectivity and Detection with Electrodes	316	(3)
Practice Questions and Problems	316	(3)
Analysis by Oxidation---Reduction Reactivity	319	(46)
Oxidation---Reduction Reactions	319	(5)
Combining Electron Half-Reactions	320	(1)
Balancing Complete Redox Reactions	321	(1)
Equilibrium Constants for Redox Reactions	322	(1)
Formal and Thermodynamic Equilibrium Constants	323	(1)
Equilibrium Concentrations	324	(3)
Approximation Method for Equilibrium Concentrations	325	(1)
Algebraic Method for Equilibrium Calculations	326	(1)
Quantitation by Redox Titration	327	(7)
Titration with Ce(IV)	328	(1)
Assuring Analyte Oxidation State Before Titration	328	(1)
Titration Curves	329	(2)
Multiple Equivalence Point Titrations	331	(1)
Equivalence Point Detection	332	(2)
Iodine and Thiosulfate	334	(3)
Log Concentration Plots	337	(8)
Redox Log Plots with a Constant Activity Reactant	338	(1)
Log Plots with Asymmetry and pH Complications	339	(1)
The Iodine, Iodide System	340	(1)
Points on Titration Curves from Log Concentration Plots	341	(4)
Karl Fischer Titration for Water	345	(2)
Quantitation by Electrolytic Redox Reaction	347	(6)
Electrolytic Reactions	347	(2)
Coulombs and Moles	349	(1)
Coulometry	350	(3)
Electrogravimetry	353	(3)
Coulometric Titration	356	(3)
Diffusion-Limited Electrodes	359	(2)
Test Strips, Spot Tests and FIA	361	(4)
Practice Questions and Problems	362	(3)
Analysis by Interphase Partition	365	(38)
The Liquid---Liquid Interface: Extraction	366	(5)
The Gas---Liquid Interface: Distillation	371	(4)
The Gas---Solid Interface: Adsorption	375	(3)
Adsorption Isotherms	376	(1)
Solid Phase Extraction	377	(1)
Continuous Partition: Chromatography	378	(7)
The Fraction of Time Spent in Each Phase	379	(1)
Moving One of the Phases	379	(2)
Measures of Effectiveness	381	(2)
Effect of Mobile Phase Flow Rate	383	(2)
Gas Chromatography	385	(8)
The Instrument	386	(1)
Sample Injection	387	(1)
The Column	388	(1)
The Detector	388	(2)
The General Elution Problem	390	(1)
Peak Overlap	391	(1)
Information Obtained from Gas Chromatograms	391	(2)
High-Performance Liquid Chromatorgraphy	393	(3)
The HPLC System	393	(2)
Partition Chromatography	395	(1)
Variations on the Chromatographic Theme	396	(2)
Planar Chromatography	397	(1)
Mass Spectrometric Detection	398	(1)
Multichannel Chromatographic Detection	399	(4)
Practice Questions and Problems	400	(3)
Analysis by Biochemical Reactivity	403	(46)
Enzyme Reactivity	404	(5)
Varieties of Enzymes and Reactivity	405	(1)
Enzyme Activation and Inhibition	406	(1)
The Effect of pH	406	(2)
Enzyme Stability	408	(1)
Kinetics of Enzyme Reactions	409	(7)
First-Order Reaction Rates	410	(1)
Enzyme-Catalyzed Reactions	410	(2)
The Michaelis---Menten Equation	412	(1)
Analytical Significance of KM and Kcat	413	(3)
Kinetic Methods of Analysis	416	(4)
Continuous Flow Methods	416	(1)
Stopped Flow Methods	417	(1)
Quenching Methods	418	(1)
Applications of Kinetic Analysis with Enzymes	418	(2)
Antigen---Antibody Reactivity	420	(4)
Antibodies and Their Generation	421	(1)
Detecting the Antibody-Antigen Reaction	422	(2)
Immobilized Enzymes and Antibodies	424	(2)
Bonding Biochemical Reagents	424	(1)
Containing Biochemical Reagents	425	(1)
Separation with Biochemical Reactions	426	(8)
Separation on the Basis of Size	426	(2)
Separation on the Basis of Complexation Reactivity	428	(2)
Separation on the Basis of Mass and Density	430	(4)
Immunoassay	434	(7)
Direct Binding Reactions	434	(2)
Competitive Binding Reactions	436	(2)
Enzyme-Linked Immunosorbent Assay (ELISA)	438	(1)
Enzyme Multiplied Immunoassay Technique (EMIT)	439	(1)
Applications of Immunoassay	440	(1)
Biochemically Based Sensors	441	(8)
Photon Emission Sensors	441	(1)
Photon Absorption Sensors	442	(1)
Electrode Potential Sensors	443	(1)
Electrode Current Sensors	444	(2)
Practice Questions and Problems	446	(3)
Background Materials	449	(12)
Stoichiometric Ratios in Chemical Compounds and Reactions	449	(3)
Molecular Formulas	449	(1)
Reaction Stoichiometry	449	(1)
Ionic Reactions	450	(1)
Combining Quantities	450	(2)
Logarithms and Exponents	452	(4)
Logarithms	452	(1)
Antilogarithms	453	(1)
``p'' Units	453	(1)
Logarithmic Scales	454	(1)
Natural Logarithms	454	(1)
Operations with Exponents	455	(1)
Addition and Subtraction	455	(1)
Multiplication and Division	455	(1)
Operations with Logarithms	455	(1)
Electrical Quantities and Their Relationships	456	(5)
Electrical Conductors and Insulators	456	(1)
Separation of Charge	457	(1)
Electrical Current	457	(1)
Electrical Capacitance	458	(1)
Electrical Signals	458	(3)
Appendices	461	(22)
A. Tables of Activity Coefficients and ax	461	(2)
1. Calculated Values of Acitivity Coefficient Using the DHE	461	(1)
2. Table of Ion Size Parameters, ax, for Inorganic Ions	462	(1)
Table of Ion Size Parameters, ax, for Organic Ions	462	(1)
B. K0a Values for Weak Acids in Water	463	(5)
C. Table of Complex Formation (K0f and K'f) Values	468	(4)
D. K0sp and K'sp Values for Some Precipitates	472	(2)
E. Standard Reduction Potentials	474	(2)
F. International Atomic Weights	476	(2)
G. Useful Constants and Conversions	478	(2)
Prefixes for Units and Their Multiplication Factors	479	(1)
H. Techniques Discussed and Their Location	480	(3)
Index	483