REPORT FOR ANALYSTS Trends in Analytical ... - ACS Publications

following World War II? Because of the breadth of analytical chemistry and the need to be somewhat arbitrary with respect to some classifications, qua...
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How much analytical research is done in comparison with research in other fields of chemistry? How does analytical research break down with respect to organic and inorganic analysis? What analytical techniques are most widely used?

Which nations are doing the most research in analysis? How

do answers to these questions compare with those of the period immediately following World War 112

Because of the breadth of analytical chemistry and

the need to be somewhat arbitrary with respect to some classifications, quantitative answers are not possible.

It is, however, possible to develop

significant trends by a proper analysis of data.

The answers to these and

several other related questions appear in this month's Report for Analysts in a study made by Robert B. Fischer and five graduate students at the Department of Chemistry, Indiana University. survey made by F. C. Strong in 1946.

It is a follow up to a related

Both surveys are based on data in

Chemical Abstracts.

y increased tempo of scientific research since theend of World War I1 has been evidenced in many ways. One obvious index is the stepped up expenditures for research and development in the United States and in most foreign nations.

Robert B. Fischer, associate professor at Indiana University since 1952, has long been interested in teaching ond research in analytical chemistry, in V O L U M E 28,

This ever-increasing tempo is reflected also in the number of scientific articles published in technical journals. A key to this growth is the steady climb in the number of articles abstracted in

Chemical Abstracts. Trends and developments in analysis,

general and electron microscopy in particular. The 36-year-old analyst received his B.S. from Wheatan College (Ill.) in 1942, and his Ph.D. in analytical chemistry at the University of Illinois in 1946. From 1944 to 1946 he worked on the Manhattan Project ot the University of Chicago. During the following two years, he served at Illinois as an instructor. In 1948, he joined the staff ot Indiana University as an assistant professor. He i s author of "Applied Electron Microscopy" ( I 943) and "Quantitative Chemical Analysis" (1946). He is active in ACS. The coauthors are all graduate students in chemistry at Indiana University, either mojoring or minoring in analytical chemistry. They are Robert F. Babcock, Robert F. Conley, Sally B. Cross, Frank A. Guthrie, and William W. Paudler.

NO. 12, D E C E M B,ER 1 9 5 6

a vital part of all disciplines of chemistry, are a good barometer of changes in the fields of chemistry. Following World War 11,Strong made a survey of papers published in the field of quantitative analysis to serve as a guide to analytical chemists and teachers of analytical chemistry [AN-. CHEM. 19, 968 (1947)J. He wished to determine such factors as: countries in which the work was done, language used, ratio between organic and inorganic analyses, type of determination, and the type of preliminary separation.. To determine what changes have taken place in the ensuing 10 years, the present authors made, with full approval of Strong, a somewhat similar study for the year 1955. It mas necessary to make arbitrary choices with respect to such factors as: Is a paper analytical or not; is it a research paper; and under what method should i t be classified? Some analytical methods are of tremendous current practical value, even though relatively little research concerning them appears in the literature. Such factors as these prevent an overly rigorous, precise mathematical evaluation of the changes. Although 9A

REPORT FOR ANALYSTS

qualitative and not quantitative, the authors feel that the comparisons are meaningful and significant in indicating in broad, general terms the current trends in analytical chemistry. Analytical Chemistry, Fast-Growing Field

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The surveys covering the 1955 and 1946 periods were made on a somewhat different basis. The 1946 study was based on all papers with a publication date in the calendar year 1946. Chemical Abstracts served as the main source of information. The 1955 study was based on papers abstracted during the calendar year 1955. This study n a s limited to one of every four issues (six out of 22 published during the year). I n making these surv’eys, certain arbitrary choices had to be made. The very naturi: of analytical chemistry, for example, makes it difficult in many cases to decide whether a particular paper should be classified as analytical or not. Classification of some papers as to method or preliminary separation presented similar difficulties. Reports of analyses by knon-n methods were not tabulated unless they included research on some phase of the method and/or the apparatus employed. Determinations of physical constants such as viscosity, density, infrared peaks for specific groupings, and half-wave potentials, were not tabulated unless these constants were directly applied to analysis in the paper or unless the data appeared directly usable for analytical purposes. I n the 1955 surrey the work was divided among several authors who, although they worked closely together. may have differed slightly in their evaluations. It was noted that Chemical Abstracts keeps remarkably up to date, as 48.0% of the analytical papers abstracted in 1955 were published that same year and 38.7y0were published in 1954. The six issues studied for 1955 included 1489 analytical papers, a larger figure than for the entire year’s issues for 1946. Projecting this figure for the full year, using a factor of 2 2 / 6 , indicates a total of about 5460 per year. This total compares with the 74,664 total number of abstracts of papers in the 1955 issues of Chemical Abstracts. In 1955, therefore, about one in 14 papers dealt with analytical chemistry. This compared with a ratio of one in 26 for 1946. Because of the factors mentioned abore, this ratio should not be considered rigorously. However, it is apparent that interest and activity in analytical chemistry are not only keep-

Table I.

C o u n t r y i n W h i c h Work Was D o n e

% of Total“ 1955

Country

United States Academic Industrial Research Institute Unknown (but

u. S.)

1946

23.8

41.6

9.3 6.3 1.7

1.4

Japan Germany Russia Great Britain Italy France India Czechoslovakia Canada Austria Spain Sweden Belgium Switzerland Hungary Netherlands Argentina Australia Chile Denmark Finland Poland Yugoslavia Egypt Israel Norway Scotland South Africa Brazil Peru Rhodesia New Zealand Greece Hawaii Romania China Ireland Mexico Palestine Puerto Rico British W e s t Indies Holland Azurbaijan Indonesia Latvia Lebanon Panama Portugal Sicily Syria

12.3

0.2 10.2 0.2 9.0 12.3 7.4 14.6 5.2 2.5 4.7 8.0 3.9 1.7 3.7 0.2 2.2 1.1 1.7 1.7 2.2 1.7 3.3 1.3 1.0 1.2 2.4 1.1 0.1 1.0 1.8 0.9 0.9 0.6 1.4 0.6 0.2 0.6 0.8 0.6 0.3 0.6 0.5 0.2 0.4 0.1 0.4 0.4 0.2

...

...

...

0.3 0.3 0.2 0.2 0.1 0.1 0.1

,.. ...

0.1 0.1 0.1

... ... ...

0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1

...

0.2 0.9 0.1 0.5 0.3 0.2 0.2 0.2 0.1 0.1 0.1 0.1 0.1 0.1

...

...

... ... ... ...

... ... ...

Based on 1385 entries.

a

Circle No. 10 A on Readers’ Service Card, page 63 A

A N A L Y T I-C A L C H E M I S T R Y

REPORT FOR ANALYSTS

ing pace with the increasing tenipo of scientific research, but are expanding more rapidly than some other areas of chemistry. Analysis Appears in Every Field

Analytical chemistry is involved, directly or indirectly, in virtually all areas of the broad field of chemistry. In Chemical Abstracts, i t was noted, only 46.3y0 of analytical papers were found in the analytical section; 1i.9% of the abstracts of analytical papers were found in the section on biological chemistry, 5.6% in pharmaceuticals, cosmetics, and perfumes, and the remaining 30.2% in all the other sections. In the samples used, the only two sectioiis in which no analytical abstracts appeared n ere explosives and explosions and acids. alkalies, salts, and heavy chemicals. I n many cases \There analytical papers involve development of analytical procedures for application to particular types of materials, the analytical information is often of Ivider interest. International Interest in Analysis

The international nature of scientific research activity was much in evidence in the survey (see Table 1). The rapid growth in certain countries, particularly Japan and Germany, was evident. Japan and Germany, for example, rose from very minor ratings in 1946 to second arid third position, respectively, by 1955. Papers from countries like Japan indicate considerable analytical activity in many fields. I n the United States, for which the authors niade a someiThat detailed breakdown, it is noted that almost 40% of the analytical research is done in academic institutions. Industry follows with 26%, government with 21%, and research institutrs with 7%. English I s Widely Used language

About half of all the analytical Papers in 1955 w r e in English, a drop of 17% from lg4' (see "1. German, which is now in second place, was in sixth place a ago* in third place, was second in 1946. French, noK in fourth place, in third place tWo years ago. Russians and French now represent almost SO% of all papers published, compared to more than 90% in 1946. These figures, like others in the study. are based on certain assumptions. One is that the language used was generally that of the country in which the journal \\.as published. The authors feel that these figures indicate the desirability of graduate

Table 11.

Language of Article % of T o t a l Language 1955" 1946

English German (including Dutch and Austrian) Russian French Italian Czechoslovakian Spanish Polish

14.4 2.9 8.6 11.6 6.0 10.4 5.3 2.4 2.8 0.1 2.4 4.3 0.4 0.4 1.4 0.1 0.2 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 9.3b 0.2 0.6'

...

... ...

Finnish Greek Hungarian

...

...

Portuguese Yugoslavian Japanese Indian b

e

4 9 . 4 66.2

...

Based on 1426 entries, Many of these were actually in English. Some of these may have been in English.

'ChoOl language rr(lllirenlents Of German and either French or Russian. It is noted, however, that English translations of some Russian journals are becoming available. Organics and lnorganics Are Equal

Analytical research \Tork is about equally divided between organic and inorganic analj-qis (see Table 111). Table 111. Organic vs. Inorganic 4nalj sis Nature of

% ___ of T o t a l __

Substance

1955u 1946

47.5 58 47.7 42 4.8

Inorganic Organic Both

' Based

On

...

l3lo entries*

It is noted, holTever, that inorganic papers tend to be concentrated in such areas as the first Seven categories of Chemical Abstracts. These are: Apparatus, plant equipment, and unit operations; general and physical chemistry; electronic phenomena and spectra; phenolllena; electrochemistry; photography; inorganic chemistry; and analStical chemistry. The organic papers appear prillcipally in the remaining 24 sections of Chemical ilbstracts which cover the other fields of chemistry. Colorimetry, Titrimetry, and

Spectrophotometry Are Leading Methods

The optical absorption methods, colorimetry and spectrophotometry, occupy a very important place in modern

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REPORT FOR ANALYSTS analysis and in analytical research (see Table IV), The two conventional categories of “classical” quantitative analysis, titrimetric and gravimetric methods, continue to hold prominent places, a fact which provides one of several reasons for continuing to emphasize them in the first course in quantitative analysis. I n fact, when potentiometric titration methods are included with visual titrimetric methods, titrimetry occupies the top position. A rapid growth in the spectrophotometric method is one of the most significant changes in methods in the past decade.

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Table IT.

Classification According to Method of Total 195P 1946

Method

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22.0

25.6

20.2 15.5

23.0 5.7

6.5 4.8

8.5 4.0

4.2

5.3

3.3

0.6

2.8 2.3 2.0

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1.1 0.5

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0.4 1.6 17.8

17.2 4.8 3.2 0.9 0.3 0.4

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Titrimetry (visual and instrumental) Titrimetry (visual) Titrimetry (instrumental) Potentiometric Amperometric Conductometric Other Colorimetry (visual and photoelectric) Spectrophotometry Visible Ultraviolet Infrared Raman Other Gravimetric Polarography Emission spectrotroscopy Arc and spark Flame X-ray methods Diffraction Fluorescence Absorption Biological assay Gas analysis Radioactivity Turbidimetry and nephelometry Microscopy Electrical conductivity Fluorescence All others

Adsorption Leads Separation Techniques Approximately one fourth of the abstracts examined dealt specifically with methods of separation prior to the final measurement. These separation methods include adsorption, extraction, precipitation, distillation, and dialysis (see Table I*). In 1955, adsorption (chromatographic

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Table V. Type of Preliminary Separation Type % of Total 1955“

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Adsorption Chromatographic Ion exchange Extraction Precipitation Distillation Dialysis OtheP

57.0

194@

28.6

45.3

11.7

18.4 18.0 5 . 2 10.3 3.0 0.9 23.9

17.9

16.9

...

Based on 402 entries. *Includes several topics which were not separation methods, so direct comparisons are not very exact.

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About one in 14 papers currently being abstracted in Chemical Abstracts falls within the subject matter of analytical chemistry; in 1946 the figure was one in 26. The United States is leading, as it was in 1946, with respect to the amount of work done in this field, The increase in some other countries since 1946, however, has been substantial, so that the L-. S. now accounts for 23.8% compared to -11.6% in 1946. I n 1955, the leaders, following the U. S., were Japan, Germany, Russia, and Great Britain. In 19-16 the leaders were, after the IT. S., Great Britain, Russia, France, and Sweden. The most j d e l y used languages were English, German, Russian, and French; in 1946 the order was English, Russian, French, and Spanish. The ratio of organic to inorganic is approximately equal nowv,compared to 58% of organic versus 42% inorganic in 1946. The analytical method most used both in 1955 and 1946 was titrimetry (visual and instrumental) , with colorimetry (visual and photoelectric), second. A close third place in 1955 was held by the various forms of spectrophotometry. In fourth and fifth places in 1955 were gravimetric methods and polarography. I n 1946, gravimetric methods held third place. Spectrophotometry and emission spectroscopy held fourth and fifth place a decade ago. Among the types of preliminary separation, the leader in 1955 and 1946 was adsorption. The 1955 figure (57%) was, however. greater than that in 1946. Second and third places in both years were the same-namely, extraction and precipitation.

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