XIV
Table of Contents
6.2.2.1 Isotope Dilution Mass Spectrometry . . . . . . . . . . 263
6.2.2.2 Titrimetry. . . . . . . . . . . . . . . . . . . . . . . . . 264
6.3 Relative Quantitation Methods . . . . . . . . . . . . . . . . . . . . . 271
6.3.1 Interpolation and Extrapolation Methods . . . . . . . . . . . 271
6.3.2 Comparative Methods . . . . . . . . . . . . . . . . . . . . . . 275
Questions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 276
Seminars . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 278
Suggested Readings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 281
7 The Analytical Problem . . . . . . . . . . . . . . . . . . . . . . . . . . 283
7.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 283
7.2 Meanings of "Problem" in Analytical Chemistry . . . . . . . . . . . 286
7.3 Integral Definition of the Analytical Problem . . . . . . . . . . . . . 286
7.4 Elements of the Analytical Problem . . . . . . . . . . . . . . . . . . 289
7.5 Steps ofthe Analytical Problem-solving Process . . . . . . . . . . . 290
7.5.1 Identifying and Confirming the Information Required . . . . 291
7.5.2 Pinpointing the Analytical Information Required . . . . . . . 292
7.5.3 Planning the Analytical Approach . . . . . . . . . . . . . . . 294
7.5.4 Monitoring the Results . . . . . . . . . . . . . . . . . . . . . . 296
7.5.5 Implementing Corrective Actions . . . . . . . . . . . . . . . . 297
7.6 Consistency Between Required Information and Supplied
Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 297
7.7 The Analytical Problem in the Context of Quality . . . . . . . . . . 299
Questions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 301
Seminars . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 304
Suggested Readings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 305
8 Analytical Chemistry and Quality ................. .. 307
8.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 308
8.2 A Generic Approach to Quality . . . . . . . . . . . . . . . . . . . . . 310
8.2.1 Integral Definition of Quality . . . . . . . . . . . . . . . . . . 310
8.2.2 Types of Quality. . . . . . . . . . . . . . . . . . . . . . . . . . 313
8.2.3 Quality Compromises . . . . . . . . . . . . . . . . . . . . . . 314
8.2.4 Structure of Quality . . . . . . . . . . . . . . . . . . . . . . . . 315
8.2.5 Benefits of Quality . . . . . . . . . . . . . . . . . . . . . . . . 316
8.3 General Aspects of Quality in Analytical Chemistry . . . . . . . . . 317
8.3.1 Types of Quality in Analytical Chemistry . . . . . . . . . . . 317
8.3.2 Quality and Analytical Properties . . . . . . . . . . . . . . . . 318
8.3.3 Quality and the Analytical Problem . . . . . . . . . . . . . . . 319
8.4 Quality Systems in the Analytical Laboratory . . . . . . . . . . . . . 319
8.4.1 Elements of Quality Assurance . . . . . . . . . . . . . . . . . . 319
8.4.2 ISO Guide 25 (EN-45000) . . . . . . . . . . . . . . . . . . . . 321
8.4.3 Good Laboratory Practices . . . . . . . . . . . . . . . . . . . . 323