What Is Analysis?
What Is the Role of the Analyst?
In the N o v e m b e r issue w e published the first i n a series of expressions of o p i n i o n on the questions: W h a t is analysis? and What i s the r o l e of the analyst? It is w i t h pleasure that w e present b e l o w additional comments from men w e l l k n o w n i n the chemical field.
R. B. Seymour. University of Chattanooga
A
is difficult to dt6nc. This is primarily due' to the confusion that, exists in academic and industrial laboratories and in the minds of the men n-ho are rcsponsihle f o i , the operation ( i f these organizations. I n the definition of mcdicine, the profession of niedicint: is taken for granted and on(%does not include first aid or nursing, wgardless of their iniportanrc. -1premedical student who cannot make the grade dot?.: not become a routine physician ncr does an orderly ticcome a doctor of medicine after he has had six mont,hs’ experiencti. Definite spheres of activity have not been c.stablished in the field of analysis, which includes t,he duties of the sample boy as well as the contributions of the world’s most outst,anding analytical chemist. There is as much difference beas practiced by the routine technician and the analytical chemist as there is between the operations of the physician and the nurse. I t is of utmost importance to the entire profession of chemistry that this difference be recognized. The problem cannot, be solved by the substitution of the letter ‘It” for l‘is.” In order not to increase the confusion it is preferable t o discuss the roles of the routine analyst and of the analytical chrmist, separately. The former is trained to do a specific job, the latter should be educated to,be of service to the professioii of chemistry. The modern undergraduate chemistry curriculuni should serve to educate rather than train students and should not produce specialists. Such a course should minimize routine and should emphasize instruction in the principles of the science of chemistry. Experiments which illustrat,e fundamental principles and those which develop laborat,ory skill can be combined if the instructor is an analytical chemist and not a routine analyst. One must decide whether to use classical methods to train routine analysts who are completely unfamiliar with statistics, spectroscopy, microanalysis, polarography, microscopy, and other tools of modern analysis or to educate creative chemists. Fortunately, the gradua,t’ewho has not spent count,less hours in titrating, washing, and weighing will not be properly qualified to become a routine analyst. He must choose some ot,her phase of work where he will not be confused with technicians, or further his education by specializing in a major branch of chemistry. There are many opport,unities open t,o one who has majored in analytical chemistry in an accredited graduat,e school. He may undertake special analyses, develop new methods, or supervise a group of routine analysts. I n no case should he accept a project unless the background of the problem is explained. Otherwise he will be unable to judge the suitability of the sample or the suggested procedure and to drcide whether or not the NALYSIS
devrlopinc~ntof procc~dui~ modifiritt ions is ju.qtifitXt1. duc.11 \ ~ o i , l ; cannot bc done b?- the roct in(, aiialyht a n d nil1 merit the' clnthusiasm of an analytical chcmist who lition-s thc prohl(xin aiitl ran present an inttllligent (:valuation of the data. T h e role of the routine analyst is t o follo\T- instructioiis. The role of tho ana1ytic:tl ch(,niist is to ascertain that thP instructions are correct and are properly carried out and to makc>good use of his technical education. If he will assume his proper role and he n-ill find it less difficult to prove to himself, his e~mployc~, the routine :inalyPtq that anal>-ticalrhcmistrj- is aprofwsion.
Harold P. Klug, Mellon Institute
A
chemistry in its most fundamental aapcct,s is far broader than the mere qualitative and quantitative deterinination of t,he elements present in a substance. An increasing array of analytical problems in the larger research institutes and industrial laboratories involves phase identification, polymorph differentiation, stereochemistry (location of groups i n the molecule), crystal structure, and ot,her concepts not ordinarily the concern of the routine analyst. I n addition, thcre arc all the complex problems attendant on continuous analysis and control in the industrial plant. .ill these problems legitiniatrly fall within the domain of analysis, but they usually call for a different approach and technique and are likely to require cxtensive instrumentation. Thus modern analytical chemistry embraces not only routine determination of the composition of substances, but also structural and physicochemical identifications. Hydrocarbon mixtures, in the past, have been an outstanding analytical problem. Although chemical methods can arcurately analyze even those mixtures of components (up to Ccor C:) ivhich cannot be separated by fractional dist’illation, the time required for such an analysis is excessive. Infrared absorption spectroscopy, however, will quant’itatively determine seven such , components in a mixture wit,h a n accuracy of about 0.5% in only one half to one hour. The mass spectrograph, likewise, will do the same analysis in approximat’elythe same time. I n the inorganic field t,here are many cases which do not lend themselves to the routine methods of analysis. An imporbant example is the det,ermination of quartz in siliceous dust,s. In studying the silicosis hazard in industry, analytical methods are needed which will differentiate and quantitatively measure quartz in the presence of other siliceous minerals. h standard method for quartz analysis utilizes the powder method of x-ray diffract’ion. The powder diffraction pattern of a crystalline compound is a characteristic physical property of the substance, and serves , ideally as a “fingerprint” for its identification, even when admixed with other materials. Quant,itative methods are bascd on the relative intensity of the pattern of a component. A particularly valuable feature of x-ray diffraction methods of analysis is their ability to distinguish bet8weenthe different allotropic or polymorphic forms of a substance. For instance, rutile and anatase, polymorphic forms of titanium dioxide, are both important in the white pigment industry, but rutile is the more desirable in paints since it has greater covering poTT-er, and therefore commands a highvr pricci. These two forms arc indintinSALYTICAL
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guishable in routine chemical analysis, but are readily differentiated and analyzed for by diffraction methods. One of the monumental achievements of x-ray diffraction was the establishing of the structure of penicillin. This was fundamentallv an analytical problem, as indeed are all problems of structure determination in newly isolated compounds. Qualitative and quantitative analysis determine the composition of the substance, but this is only half of the problem. The structure, the positions of its atoms, distinguishes a compound from the others isomeric with it. The complete list of modern physical and physical chemical techniques available to the analyst is large, and has led to a new terminology, “analytical physics.” These new tools require specialists for many phases of their application, but their utility and pon er are making them standard facilities of large research, analytical, and control laboratories. Every research chemist today needs a t least a speaking acquaintance with these new tools; otherwise he will not know what important aids they can be in the solution cf his problems. The trained analytical chemist, of course, should have a real working knowledge of the entire field of modern instrumental analysis. The proper fraining of future research chemists and analytical specialists must emphasize the larger sigmficance of analytical chemistry. Few colleges and universities are prepared to do this job effectively a t the moment, but many are cognizant of the problem and are planning instrumentation laboratories. Such laboratories should have associated with them specialists in optical spectroscopy, mass spectroscopy, x-ray diffraction, polarography, and other instrumental techniques if they arc to provide anything more than additional elementary laboratory exercises in physical chemistry. The analytical specialist could profit by additional courses in physics, particularly optics and electronics. Finally, a survey type of course in which the various instrumental analysis fields are each discussed in a few lectures by a recognized authority could be very valuable.
Paul D. V. Manning, International Minerals & Cheaeal Corp.
A
work and treatment of results obtained form the means of judging and interpreting practically all research and development in all fields of science. Accuracv of results and statistical treatment of such results are therefore of paramount importance. There is also one other factor of equal rank but one which is generally given little consideration in the training of the professional worker. This is the speed of obtaining results. More often than is generally realized, the position of a corporation in a field of enterprise depends on the speed a t which its research and development organization can complete an investigation. The bottleneck all too frequently is found in the great volume of analytical work required. Because of the greatly increased costs of all types of research, it is also worth while to try to shorten the time required for all operations, but accuracy of results must never be sacrificed. Our activities in research and development are in many fieldsfrom prospecting thousands of acres of, phosphate and potash ores with analysis of thousands of samples for several constituents, through complex organic syntheses where analytical methods must be invented, to the chemical analysis of crops grown in large field agronomy tests where statistical treatment of results is of highest import, and to continuous, round-the-clock pilot-plant operation where .the planning of the next day’s work depends on analytical results obtained today. For all these, we have turned t o use of new instruments which have usually been developed by physicists and physical chemists. Instruments such as the spectrophotometer, the flame photometer, the polarograph, and others have been of great assistance and have made it possible to discover new phenomena in old fields. The principal difficulty has been in finding men trained in the use of instruments and having a sufficient knowledge of NALYTICAL
physics to enable them to make applications in new fields. For this, we look for men who are primarily physicists trained in chemistry and mathematics, physical chemists, or those very rare finds-ehemjsts who have had more courses in physics than are given in the usual curriculum. A ,constantly revised excellent course in instrumental analysis is an essential; additional courses in physics are advisable for all chemists, and a courye in statistics is an invaluable aid to any scientific worker.
Edward Wichers, National Bureau of Standards
W
HEX the analytical chemist occasionally pauses from the exertion of keeping up Kith his daily tasks he is apt to wonder what has happened to the dignity of his profession. If he thinks back over the history of chemistry he may ponder sadly that although his scientific progenitors occupied the center of the chemical stage throughout a great part of the nineteenth century, they at last lost the spotlight-first to Kekul6 and his tribe, then to Willard Gibbs and his spiritual descendants. While the physical chemist never entirely stole the show from the organic chemist, and more recently has had t o share it with still others, the analytical chemist feels in his gloomier moments that for him there is little left but a stage hand’s job. If there is justification for this pessimism, why has the once glorious profession been so debased? In this writer’s opinion a major reason is that the analytical chemist too often forgets that he is a chemist and behaves as if he were only a technician. Today we have experts in microanalysis, optical and mass spectrometry, and every other specialized technique one can think of. The analyst is acquiring an easy familiarity with electronic gadgets and is beginning t o feel somewhat at home in optics. But too many of u9 give too little thought t o underlying phenomena and to the relation of our activities to the world of chemistry. In the morning we receive a sample about whose significance we do not inquire. In the evening we turn in a report and go home to our supper, little knowing or caring what it all means. For a large part of the nineteenth century, the major task of the chemist was t o resolve the things he saw into their constituent parts-in other words, the analysis of natural materials. Each day brought something new to do that required some new thinking. Today chemistry is mainly concerned with reshaping the materials of nature t o suit man’s needs, and the analyst must meet the resulting demands for the chemical control of processes and product quality. A large part of his effort must now be spent on providing methods suitable for rapid and repetitive use, the more mechanical in operation the better. The progress made in the development of instrumental methods in the past twenty or thirty years is truly astonishing, and the end is not in sight. These techniques are indispensable, and the analytical chemist must produce them. But they are the product of analytical chemistry and not analytical chemistry itself. This should never be lost sight of, and the distinction should be clearly and insistently brought out in the teaching of analytical chemistry. If we define the objective of analytical chemistry as the discovery of a sufficient number of chemical and physical phenomena t o determine uniquely the presence and concentration of any component (elementary or molecular) of any conceivable chemical system, we see a t once that there can be a dignified career for the analytical chemist for a long time to come. Today there is as great a need as there ever was for knowledge of reactions that will serve to identify, to separate, and to determine elements, radicals, and compounds ever more sensitively, more accurately, and more rapidly. To discover them the analytical chemist needs the broadest possible knowledge of chemistry-inorganic, organic, and physical. Of all the family of chemists, he should be a chemist complete, as were his nineteenth century forebears. If the practitioner, and more especially the teacher, of analytical chemistry will firmly cling to this faith, this branch of qur science may hope t o regain some of its lost glory.
