Analytical Chemistry for Technicians

Analytical Chemistry for Technicians, Third Edition......Page 2
Dedication......Page 4
Preface......Page 5
Acknowledgments......Page 6
The Author......Page 8
Safety in the Analytical Laboratory......Page 9
Contents......Page 11
Table of Contents......Page 0
1.1 Analytical Science Defined......Page 25
1.2 Classifications of Analysis......Page 26
1.3 The Sample......Page 27
1.5 Analytical Technique and Skills......Page 28
1.6 The Laboratory Notebook......Page 31
1.7.1 Errors......Page 33
1.7.2 Elementary Statistics......Page 34
1.7.3 Normal Distribution......Page 35
1.7.4 Precision, Accuracy, and Calibration......Page 36
1.7.5 Statistical Control......Page 37
Experiment 1: Assuring the Quality of Weight Measurements......Page 38
Questions and Problems......Page 39
2.2 Obtaining the Sample......Page 41
2.3 Statistics of Sampling......Page 43
2.4.2 Maintaining Sample Integrity......Page 44
2.5 Sample Preparation: Solid Materials......Page 46
2.5.3 Solid–Liquid Extraction......Page 47
2.5.4 Other Extractions from Solids......Page 48
2.5.5 Total Dissolution......Page 49
2.6.1 Extraction from Liquid Solutions......Page 52
2.6.2 Dilution, Concentration, and Solvent Exchange......Page 53
2.7 Reagents Used in Sample Preparation......Page 54
Experiment 3: A Study of the Dissolving Properties of Water, Some Common Organic Liquids, and Laboratory Acids......Page 55
Questions and Problems......Page 57
3.3 The Balance......Page 60
3.4 Calibration and Care of Balances......Page 62
3.6.1 Physical Separation Methods and Calculations......Page 63
3.6.1.1 Loss on Drying......Page 64
3.6.1.3 Residue on Ignition......Page 66
3.6.1.4 Insoluble Matter in Reagents......Page 67
3.6.1.5 Solids in Water and Wastewater......Page 68
3.6.1.6 Particle Size by Analytical Sieving......Page 69
3.6.3 Gravimetric Factors......Page 71
3.6.4 Using Gravimetric Factors......Page 73
3.7.1 Weighing Bottles......Page 74
3.7.3 Isolating and Weighing Precipitates......Page 75
Experiment 4: Practice of Gravimetric Analysis Using Physical Separation Methods......Page 77
Experiment 5: The Percent of Water in Hydrated Barium Chloride......Page 79
Experiment 6: The Gravimetric Determination of Sulfate in a Commercial Unknown......Page 80
Experiment 7: The Gravimetric Determination of Iron in a Commercial Unknown......Page 82
Questions and Problems......Page 84
4.2 Terminology......Page 88
4.3.1 Molarity......Page 90
4.3.2 Normality......Page 91
4.4.1 Solid Solute and Molarity......Page 93
4.4.2 Solid Solute and Normality......Page 94
4.5 Stoichiometry of Titration Reactions......Page 95
4.6.1 Standardization Using a Standard Solution......Page 96
4.6.2 Standardization Using a Primary Standard......Page 98
4.7 Percent Analyte Calculations......Page 100
4.8.1 The Volumetric Flask......Page 102
4.8.2 The Pipet......Page 105
4.8.3 The Buret......Page 109
4.8.4 Cleaning and Storing Procedures......Page 110
4.9.2 Pipetters......Page 111
4.9.4 Digital Burets and Automatic Titrators......Page 112
4.11 Analytical Technique......Page 113
Experiment 8: Preparation and Standardization of HCl and NaOH Solutions......Page 115
Questions and Problems......Page 116
5.2 Acid–Base Titrations and Titration Curves......Page 121
5.2.2 Titration of Weak Monoprotic Acids......Page 122
5.2.4 Equivalence Point Detection......Page 123
5.2.5 Titration of Polyprotic Acids: Sulfuric Acid and Phosphoric Acid......Page 125
5.2.7 Titration of Tris-(hydroxymethyl)amino Methane......Page 127
5.2.8 Titration of Sodium Carbonate......Page 128
5.2.9 Alkalinity......Page 129
5.2.10 Back Titrations......Page 130
5.2.11 The Kjeldahl Method for Protein......Page 131
5.2.12 Buffering Effects and Buffer Solutions......Page 135
5.3.2 Complex Ion Terminology......Page 139
5.3.3 EDTA and Water Hardness......Page 142
5.3.4.1 Solution Preparation......Page 145
5.3.5 Water Hardness Calculations......Page 146
5.4.1 Review of Basic Concepts and Terminology......Page 149
5.4.2 The Ion-Electron Method for Balancing Equations......Page 152
5.4.3 Analytical Calculations......Page 153
5.4.4.1 Potassium Permanganate......Page 154
5.4.4.2 Iodometry: An Indirect Method......Page 155
5.5 Other Examples......Page 156
Experiment 11: Titrimetric Analysis of a Commercial Soda Ash Unknown for Sodium Carbonate......Page 157
Experiment 12: Determination of Protein in Macaroni by the Kjeldahl Method......Page 158
Experiment 13: Analysis of Antacid Tablets......Page 159
Experiment 14: Determination of Water Hardness......Page 160
Questions and Problems......Page 161
6.1 Review of the Analytical Strategy......Page 170
6.2 Instrumental Analysis Methods......Page 172
6.3.1 Sensors, Signal Processors, Readouts, and Power Supplies......Page 174
6.3.2 Some Basic Principles of Electronics......Page 175
6.4 Details of Calibration......Page 178
6.4.1 Thermocouples: An Example of a Calibration......Page 179
6.4.2 Calibration of an Analytical Instrument......Page 180
6.4.3 Mathematics of Linear Relationships......Page 181
6.4.4 Method of Least Squares......Page 182
6.5 Preparation of Standards......Page 183
6.6.2 Sample Blanks......Page 184
6.7 Effects of Sample Pretreatment on Calculations......Page 185
6.8.1 Data Acquisition......Page 187
Experiment 15: Voltage, Current, and Resistance......Page 188
Experiment 16: Checking the Calibration of a Temperature Sensor......Page 191
Experiment 17: Working with an Instrumentation Amplifier......Page 192
Experiment 18: Use of a Computer in Laboratory Analysis......Page 195
Questions and Problems......Page 196
7.2 Characterizing Light......Page 200
7.2.1 Wavelength, Speed, Frequency, Energy, and Wavenumber......Page 201
7.3 The Electromagnetic Spectrum......Page 205
7.4.1 Brief Summary......Page 206
7.4.2 Atoms vs. Molecules and Complex Ions......Page 208
7.4.3 Absorption Spectra......Page 209
7.4.4 Light Emission......Page 212
7.5 Absorbance, Transmittance, and Beer’s Law......Page 214
7.6 Effect of Concentration on Spectra......Page 217
Experiment 19: Colorimetric Analysis of Prepared and Real Water Samples for Iron......Page 218
Experiment 21: The Determination of Phosphorus in Environmental Water......Page 219
Questions and Problems......Page 220
8.2.1 Sources......Page 225
8.2.2 Wavelength Selection......Page 226
8.2.2.2 Monochromators......Page 227
8.2.3 Sample Compartment......Page 229
8.2.3.2 Beamsplitting and Chopping......Page 230
8.2.3.3 Double-Beam Designs......Page 231
8.2.5 Diode Array Instruments......Page 232
8.3 Cuvette Selection and Handling......Page 233
8.4.2 Deviations......Page 234
8.4.4 Troubleshooting......Page 235
8.5 Fluorometry......Page 236
8.6 Introduction to IR Spectrometry......Page 238
8.7 IR Instrumentation......Page 239
8.8.1 Liquid Sampling......Page 240
8.9.2 Thin Film Formed by Solvent Evaporation......Page 245
8.9.4 Nujol Mull......Page 246
8.9.5.2 Internal Reflectance......Page 248
8.9.6 Gas Sampling......Page 249
8.10 Basic IR Spectra Interpretation......Page 250
8.11 Quantitative Analysis......Page 253
Experiment 23: Determination of Nitrate in Drinking Water by UV Spectrophotometry......Page 254
Experiment 25: Qualitative Analysis by Infrared Spectrometry......Page 255
Experiment 27: Identifying Minor Components of Commercial Solvents......Page 256
Questions and Problems......Page 257
9.1 Review and Comparisons......Page 264
9.2 Brief Summary of Techniques and Instrument Designs......Page 265
9.3.1 Flames and Flame Processes......Page 267
9.3.2 Spectral Line Sources......Page 268
9.3.2.1 Hollow Cathode Lamp......Page 269
9.3.3 Premix Burner......Page 270
9.3.4 Optical Path......Page 272
9.3.5.1 Slits and Spectral Lines......Page 273
9.3.5.3 Lamp Alignment......Page 274
9.3.6.1 Chemical Interferences......Page 275
9.4.1 General Description......Page 277
9.5 Inductively Coupled Plasma......Page 280
9.6.1 Flame Photometry......Page 284
9.6.5 Atomic Fluorescence......Page 285
9.7 Summary of Atomic Techniques......Page 286
Experiment 30: Verifying Optimum Instrument Parameters for Flame AA......Page 287
Experiment 32: The Analysis of Snack Chips for Sodium by Atomic Absorption......Page 289
Experiment 34: The Determination of Sodium in Soda Pop......Page 290
Questions and Problems......Page 291
10.1 Introduction to X-Ray Methods......Page 294
10.2 X-Ray Diffraction Spectroscopy......Page 295
10.3.2 Applications......Page 299
10.4.1 Introduction......Page 300
10.4.2 Instrumentation......Page 301
10.4.3 The NMR Spectrum......Page 303
10.4.3.1 Chemical Shifts......Page 304
10.4.3.2 Peak Splitting and Integration......Page 305
10.5.3 The Magnetic Sector Mass Spectrometer......Page 306
10.5.5 The Time-of-Flight Mass Spectrometer......Page 307
10.5.6 Mass Spectra......Page 308
10.5.7 Mass Spectrometry Combined with Inductively Coupled Plasma......Page 309
10.5.8 Mass Spectrometry Combined with Instrumental Chromatography......Page 311
Questions and Problems......Page 313
11.2 Recrystallization......Page 318
11.3 Distillation......Page 319
11.4.2 The Separatory Funnel......Page 321
11.4.3 Theory......Page 323
11.4.4 Percent Extracted......Page 324
11.4.6 Evaporators......Page 325
11.5 Solid–Liquid Extraction......Page 326
11.6 Chromatography......Page 329
11.7.1 Partition Chromatography......Page 330
11.7.2 Adsorption Chromatography......Page 331
11.7.4 Size Exclusion Chromatography......Page 332
11.8.1 Paper and Thin-Layer Chromatography......Page 334
11.8.2 Classical Open-Column Chromatography......Page 336
11.8.3 Instrumental Chromatography......Page 337
11.8.4 The Instrumental Chromatogram......Page 338
11.8.5 Quantitative Analysis with GC and HPLC......Page 343
11.9.1 Introduction......Page 344
11.9.2 Paper Electrophoresis......Page 345
11.9.3 Gel Electrophoresis......Page 346
Experiment 35: Extraction of Iodine with Heptane......Page 347
Experiment 37: Solid–Liquid Extraction: Determination of Nitrite in Hot Dogs......Page 348
Experiment 38: The Thin-Layer Chromatography Analysis of Cough Syrups for Dyes......Page 349
Questions and Problems......Page 350
12.1 Introduction......Page 355
12.3 Sample Injection......Page 357
12.4.1 Instrument Logistics......Page 359
12.4.2 Packed, Open-Tubular, and Preparative Columns......Page 360
12.4.3 The Nature and Selection of the Stationary Phase......Page 362
12.5.1 Column Temperature......Page 363
12.6 Detectors......Page 365
12.6.1 Thermal Conductivity......Page 366
12.6.2 Flame Ionization Detector......Page 367
12.6.3 Electron Capture Detector......Page 368
12.6.7 GC-MS and GC-IR......Page 369
12.7 Qualitative Analysis......Page 370
12.8.2 The Response Factor Method......Page 371
12.8.3 Internal Standard Method......Page 372
12.9.1 Diminished Peak Size......Page 373
12.9.3 Altered Retention Times......Page 374
12.9.6 Appearance of Unexpected Peaks......Page 375
Experiment 40: A Qualitative Gas Chromatographic Analysis of a Prepared Sample......Page 376
Experiment 42: The Determination of Ethanol in Wine by Gas Chromatography and the Internal Standard Method......Page 377
Experiment 44: A Study of the Effect of the Changing of GC Instrument Parameters on Resolution......Page 378
Questions and Problems......Page 379
13.1.2 Comparisons with GC......Page 385
13.2 Mobile Phase Considerations......Page 386
13.3.1 Pumps......Page 389
13.3.2 Gradient vs. Isocratic Elution......Page 390
13.4 Sample Injection......Page 391
13.5.1 Normal Phase Columns......Page 392
13.5.3 Adsorption Columns......Page 393
13.5.4 Ion Exchange and Size Exclusion Columns......Page 394
13.5.5 Column Selection......Page 395
13.6.1 UV Absorption......Page 396
13.6.3 Fluorescence......Page 397
13.6.4 Refractive Index......Page 398
13.6.5.1 Conductivity......Page 399
13.6.5.2 Amperometric......Page 400
13.6.6 LC-MS and LC-IR......Page 401
13.7 Qualitative and Quantitative Analyses......Page 402
13.8.4 Air Bubbles......Page 403
Experiment 46: The Quantitative Determination of Methyl Paraben in a Prepared Sample by HPLC......Page 404
Experiment 48: Designing an Experiment for Determining Caffeine in Coffee and Tea......Page 406
Questions and Problems......Page 407
14.1 Introduction......Page 411
14.2 Transfer Tendencies: Standard Reduction Potentials......Page 412
14.4 The Nernst Equation......Page 415
14.5.1.1 The Saturated Calomel Reference Electrode......Page 417
14.5.2.1 The pH Electrode......Page 419
14.5.2.2 The Combination pH Electrode......Page 420
14.5.2.3 Ion-Selective Electrodes......Page 421
14.5.3 Other Details of Electrode Design......Page 422
14.5.5 Potentiometric Titrations......Page 423
14.6.2 Amperometry......Page 425
14.7 Karl Fischer Titration......Page 426
14.7.3 The Volumetric Method......Page 427
Experiment 50: Determination of the pH of Soil Samples......Page 429
Experiment 51: Red Cabbage Extract, the pH Electrode, and PowerPoint: A Group Project and Oral Presentation......Page 430
Experiment 52: Potentiometric Titration of Phosphoric Acid in Soda Pop......Page 431
Experiment 53: Operation of Metrohm Model 701 Karl Fischer Titrator (for Liquid Samples)......Page 432
Questions and Problems......Page 433
15.2.1 Introduction......Page 436
15.2.4 Capillary Viscometry......Page 437
15.2.5 Rotational Viscometry......Page 439
15.3.2 DTA and DSC......Page 441
15.3.3 DSC Instrumentation......Page 443
15.4 Refractive Index......Page 444
15.5 Optical Rotation......Page 447
15.6.1 Introduction to Density......Page 449
15.6.3 The Density of Irregularly Shaped Solids......Page 450
15.6.4 The Density of Liquids......Page 451
15.6.6 Specific Gravity......Page 453
15.6.7 Hydrometers......Page 454
15.6.9 Density Gradient Columns......Page 455
15.7.2 Sieves and Screen Analysis......Page 456
15.7.3 Data Handling and Analysis......Page 457
15.7.4 Histogram Representation......Page 458
15.7.5 Fractional and Cumulative Representations......Page 459
15.7.7 Electrozone Sensing......Page 462
15.8.1 Impact Testing......Page 464
15.9.1 Introduction......Page 467
15.9.2 The Stress–Strain Diagram......Page 468
15.10.1 Introduction......Page 469
15.10.2 Simple Hardness Tests......Page 470
15.10.3 Indentation Hardness Tests......Page 471
15.10.6 The Knoop Microhardness Test......Page 472
Experiment 54: Capillary Viscometry......Page 473
Experiment 56: Measuring Refractive Index......Page 474
Experiment 57: Particle Size Analysis......Page 475
Experiment 58: Tensile Testing of Polymers Using a Homemade Tester......Page 477
Questions and Problems......Page 478
16.2.1 Carbohydrates......Page 481
16.2.2 Lipids......Page 483
16.2.3.2 Peptides......Page 485
16.2.3.3 Proteins: Primary Structure......Page 486
16.2.3.5 Proteins: Tertiary Structure......Page 487
16.2.4 Nucleic Acids......Page 488
16.3.2 Electrophoresis......Page 491
16.3.3 Chromatography......Page 492
16.3.3.3.1 Columns......Page 493
16.3.3.3.3 Other Considerations......Page 495
Experiment 59: Qualitative Testing of Food Products for Carbohydrates......Page 496
Experiment 60: Fat Extraction and Determination......Page 497
Experiment 61: Identification of Amino Acids in Food by Paper Chromatography......Page 498
Experiment 63: HPLC Separation of Nucleotides......Page 499
Experiment 65: Restriction Endonuclease Cleavage of DNA......Page 500
Experiment 66: Separation of Restriction Enzyme Digestion Fragments via Horizontal Agarose Gel Electrophoresis......Page 501
Questions and Problems......Page 502
A1.1 General Provisions......Page 503
A1.3 Facilities......Page 505
A1.6 Test, Control, and Reference Substances......Page 506
A1.9 Disqualification of Testing Facilities......Page 507
Appendix 2: Significant Figure Rules......Page 508
Appendix 3: Stoichiometric Basis for Gravimetric Factors......Page 510
Appendix 4: Solution and Titrimetric Analysis Calculation Formulas......Page 511
Appendix 5: Answers to Questions and Problems......Page 514