3.S: The Vocabulary of Analytical Chemistry (Summary)

Every discipline has its own vocabulary. Your success in studying analytical chemistry will improve if you master this vocabulary. Be sure that you understand the difference between an analyte and its matrix, a technique and a method, a procedure and a protocol, and a total analysis technique and a concentration technique.

In selecting an analytical method we consider criteria such as accuracy, precision, sensitivity, selectivity, robustness, ruggedness, the amount of available sample, the amount of analyte in the sample, time, cost, and the availability of equipment. These criteria are not mutually independent, and it often is necessary to find an acceptable balance between them.

In developing a procedure or protocol, we give consideration to compensating for interferences, calibrating the method, obtaining an appropriate sample, and validating the analysis. Poorly designed procedures and protocols produce results that are insufficient to meet the needs of the analysis.

3.8.1 Key Terms

accuracy analysis analyte calibration calibration curve concentration techniques detection limit determination interferent

matrix measurement method method blank precision procedure protocol QA/QC robust

rugged selectivity selectivity coefficient sensitivity signal specificity technique total analysis techniques validation

Additional Resources

Gathered here are three types of resources: suggested experiments, mostly from the Journal of Chemical Education and The Chemical Educator, that provide practical examples of concepts in the textbook; additional readings from the analytical literature that extend and supplement topics covered in the textbook. Although primarily intended for the use of instructors, these resources also will benefit students who wish to pursue a topic at more depth.

The International Union of Pure and Applied Chemistry (IUPAC) maintains a web-basead compendium of analytical terminology. You can find it at the following web site.

• http://old.iupac.org/publications/analytical_compendium/

The following papers provide alternative schemes for classifying analytical methods.

• Booksh, K. S.; Kowalski, B. R. “Theory of Analytical Chemistry,” Anal. Chem. 1994, 66, 782A–791A.
• Phillips, J. B. “Classification of Analytical Methods,” Anal. Chem. 1981, 53, 1463A–1470A.
• Valcárcel, M.; Luque de Castro, M. D. “A Hierarchical Approach to Analytical Chemistry,” Trends Anal. Chem. 1995, 14, 242–250.
• Valcárcel, M.; Simonet, B. M. “Types of Analytical Information and Their Mutual Relationships,” Trends Anal. Chem. 1995, 14, 490–495.

Further details on criteria for evaluating analytical methods may be found in the following series of papers.

• Wilson, A. L. “The Performance-Characteristics of Analytical Methods”, Part I-Talanta, 1970, 17, 21–29; Part II-Talanta, 1970, 17, 31–44; Part III-Talanta, 1973, 20, 725–732; Part IV-Talanta, 1974, 21, 1109-1121.

For a point/counterpoint debate on the meaning of sensitivity consult the following two papers and two letters of response.

• Ekins, R.; Edwards, P. “On the Meaning of ‘Sensitivity’,” Clin. Chem. 1997, 43, 1824–1831.
• Ekins, R.; Edwards, P. “On the Meaning of ‘Sensitivity:’ A Rejoinder,” Clin. Chem. 1998, 44, 1773–1776.
• Pardue, H. L. “The Inseparable Triangle: Analytical Sensitivity, Measurement Uncertainty, and Quantitative Resolution,” Clin. Chem. 1997, 43, 1831–1837.
• Pardue, H. L. “Reply to ‘On the Meaning of ‘Sensitivity:’ A Rejoinder’,” Clin. Chem. 1998, 44, 1776–1778.

Several texts provide analytical procedures for specific analytes in well-defined matrices.

• Basset, J.; Denney, R. C.; Jeffery, G. H.; Mendham, J. Vogel’s Textbook of Quantitative Inorganic Analysis, 4th Edition; Longman: London, 1981.
• Csuros, M. Environmental Sampling and Analysis for Technicians, Lewis: Boca Raton, 1994.
• Keith, L. H. (ed) Compilation of EPA’s Sampling and Analysis Methods, Lewis: Boca Raton, 1996
• Rump, H. H.; Krist, H. Laboratory Methods for the Examination of Water, Wastewater and Soil, VCH Publishers: NY, 1988.
• Standard Methods for the Analysis of Waters and Wastewaters, 21st Edition, American Public Health Association: Washington, D. C.; 2005.

For a review of the importance of analytical methodology in today’s regulatory environment, consult the following text.

• Miller, J. M.; Crowther, J. B. (eds) Analytical Chemistry in a GMP Environment, John Wiley & Sons: New York, 2000.

References

1. Taylor, J. K. Anal. Chem. 1983, 55, 600A–608A.
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3. IUPAC Compendium of Chemical Terminology, Electronic version, http://goldbook.iupac.org/S05606.html.
4. (a) Persson, B-A; Vessman, J. Trends Anal. Chem. 1998, 17, 117–119; (b) Persson, B-A; Vessman, J. Trends Anal. Chem. 2001, 20, 526–532.
5. Valcárcel, M.; Gomez-Hens, A.; Rubio, S. Trends Anal. Chem. 2001, 20, 386–393.
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8. (a) Sandell, E. B.; Elving, P. J. in Kolthoff, I. M.; Elving, P. J., eds. Treatise on Analytical Chemistry, Interscience: New York, Part I, Vol. 1, Chapter 1, pp. 3–6; (b) Potts, L. W. Quantitative Analysis–Theory and Practice, Harper and Row: New York, 1987, pp. 12.
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9. Valcárcel, M.; Ríos, A. Anal. Chem. 1993, 65, 781A–787A.
10. (a) Amore, F. Anal. Chem. 1979, 51, 1105A–1110A; (b) Taylor, J. K. Anal. Chem. 1981, 53, 1588A–1593A.
11. D’Elia, C. F.; Sanders, J. G.; Capone, D. G. Envrion. Sci. Technol. 1989, 23, 768–774.
12. Jiménez-Prieto, R.; Velasco, A.; Silva, M; Pérez-Bendito, D. Anal. Chem. Acta 1992, 269, 273–279.
13. Oungpipat, W.; Alexander, P. W. Anal. Chim. Acta 1994, 295, 36–46.
14. Ibrahim, M. S.; Ahmad, M. E.; Temerk, Y. M.; Kaucke, A. M. Anal. Chim. Acta 1996, 328, 47–52.

Contributors

• David Harvey (DePauw University)