EDITOR: GEORGE H. MORRISON EDITORIAL HEADQUARTERS 1155 Sixteenth St., N.W. Washington, D.C. 20036 Phone: 202-872-4570 Teletype: 710-8220 151 Executive Editor; Josephine M. Petruzzi Managing Editor: Barbara Cassan Assistant Editor: Stuart A. Borman Editorial Assistant: Jacquelyn Danes Production Manager: Leroy L. Corcoran Art Director: John V. Sinnen Staff Artist: Linda M. Mattingly Copy Editor: Gail M. Mortenson Circulation: Cynthia G. Smith Journals Dept., Columbus, Ohio Associate Head: Marianne Brogan Assistant Editor: Rodney L. Temos Advisory Board L. S.Birks, Donald D. Bly, Peter Carr, Georges Guiochon, Kurt F. J. Heinrich. Bruce R. Kowalski, Robert A. Libby, Marvin Margoshes, Robert S.McDonald, James W. Mitchell, Royce W. Murray, Richard S.Nicholson, Garry A. Rechnitz, Walter Savin, John P. Walters lnstrurnentatlon Advisory Panel: Nelson L. Alpert, Stuart P. Cram, Catherine Fenselau, Gary M. Hieftje, Tomas Hirschfeld, C. David Miller, Carter L. Olson, Thomas H. Rldgway, Yair Talmi Contributing Editor, The Analytical Approach: Jeanette G. Grasseili The Analytical Approach Advisory Panel: Edward C. Dunlop, Robert A. Hofstader, Wilbur D. Shults Regulatory Affalrs, Analytical Dlvision Committee: Fred Freeberg (Chairman) Published by the AMERICAN CHEMICAL SOCIETY 1155 16th Street, N.W. Washington, D.C. 20036
Books and Journals Dlvlslon Director: D. H. Michael Bowen Journals: Charles R. Bertsch Production: Elmer Pusey, Jr. Research and Development: Seldon W. Terrant Manuscript requirements are published in the January 1980 issue, page 219. Manuscripts for publication (4 copies) should be submitted to ANALYTICAL CHEMISTRY at the ACS Washington address.
%hemistry Analytical Controversies I t is the goal of every analyst t o achieve high accuracy and precision in his measurements, since the product of a quantitative analysis is a number t h a t should approximate the true value of the population sampled. Unfortunately, this is often a n elusive goal, as evidenced by controversies over the years between different scientists and laboratories regarding the analysis of the same or similar samples. T h e most recent example of disagreement, described in FOCUS in the September and October issues of ANALYTICAL CHEMISTRY,concerns the determination of crystalline silica in the volcanic ash of Mount St. Helens. This is a question of considerable importance because of its potential health hazard. Although one usually is not surprised when sophomore quant students’ results exhibit a substantial spread, when professionals with considerable experience and excellent facilities disagree in the analysis of important real samples we are disturbed. I t is safe to assume that disagreement between laboratories is as old as chemistry. I t is the rare analytical chemist who has not been involved in one or another round-robin program to determine accepted values for a given sample, be it biological, geological, metallurgical, etc. Two dramatic cases of disagreement over results come to mind. T h e first involved the determination of impurities in uranium on the Manhattan Project during World War 11. A number of laboratories were frantically trying to resolve differences in results obtained using classical chemical methods and some of the “sophisticated” instrumental methods of that time. The controversy was finally resolved by having the chemists from the different laboratories work through the procedures together in the same laboratory. Lo and behold, systematic errors suddenly became apparent to all. T h e second notorious case, about 25 years later, involved the most expensive round robin ever mounted, the Apollo Lunar Analysis Program. In a study on “Evaluation of Lunar Elemental Analysis” (Anal. Chem. 1971,43, 22-31 A) an assessment was made of the quality of results on elemental composition of a specific lunar soil sample that had been analyzed by a substantial number of laboratories using a wide variety of techniques. Wide ranges in concentration had been reported for the various elements, and the study assessed the influence of such factors as level of concentration, technique used, sample heterogeneity, and contamination. While all these factors contributed in varying degrees, the ultimate conclusion was that some laboratories consistently performed better than others. While objectivity dictates the independent analysis of samples by the respective parties participating in any major program, past experience demands that the participants get together to resolve differences in methodology. Only then can controversies like the Mount St. Helens analyses be resolved satisfactorily.
The American Chemical Society and its editors assume no responsibility for the statements and opinions advanced by contributors. Views expressed in the editorials are those of the editors and do not necessarily represent the official position of the American Chemical Society.
ANALYTICAL CHEMISTRY, VOL. 52, NO. 12, OCTOBER 1980
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