Historical notes at the Department of Analytical Chemistry

By Professor Bengt Nygård

From the retrospective survey of the development of chemistry in Uppsala by Arne Fredga it is evident that analytical chemistry on few occasions can be found as a separate subject. The main reason for this situation may be the fact that analytical techniques frequently have been incorporated in the general chemical research. Therefore a real separation has not been accounted for until very late.

Torben Bergman

Torben BergmanTorbern Bergman's contributions to analytical chemistry already in the eighteenth century are well documented. Even if he in the beginning was not a chemist his work on the development of the qualitative and quantitative analytical chemistry has been of fundamental importance. For all future Bergman's name is closely connected to analytical chemistry, not forgetting all his efforts in other areas of science.

It was not until late in the nineteenth century that analytical chemistry was again and formally represented in education and research. In 1862 Johan Fredrik Bahr entered a position as associate professor and his successor Lars Fredrik Nilsson was in 1878 appointed extraordinary professor in analytical chemistry. During the first half of this century analytical chemistry was again assimilated into the new sharing of chemistry, mainly general and inorganic chemistry and organic chemistry as the heavy parts.

Central analytical laboratory

In the report from the Research Committee of Science 1945 concerning the future requirements for research it was suggested to establish a central analytical laboratory at the University of Uppsala. It should be attached to the chemical institute, commissioned to participate in the education in analytical chemistry as well as constitute an organisation for basic research. Furthermore, the laboratory should work as a consulting and effectuating unit for external analytical problems with preference for the faculty. To secure a high standard for this laboratory right from the beginning the head should be in a position of associate professor.

According to the proposals the new chair was established on July 1, 1946 and Folke Nydahl was the first to enter the duty in 1947. Nydahl, also lecturer in chemistry at the Agricultural College of Sweden, was earlier director of the Official Laboratory of Agricultural Chemistry in Kristianstad. Nydahl's previous research activities in analytical chemistry design of the institute. However, Widman obviously tried to provide for different interests and the building probably corresponded quite well to the requirements of a modern chemical institute at the turn of the century. It was inaugurated on the 2:th of September 1904. Cleve was on leave from the beginning of the term and retired in February 1905. At this point the designations of the chairs were changed and Widman was made Professor of Chemistry (ordinarius) with teaching responsibilities in organic chemistry. It was decreed that the holder of the other professorship should teach general and inorganic chemistry.

Widman's research work had slown down during the building period but it was now revived to its full extent and directed towards oxido compounds. Sven Bodforss and Henrik Jörlander were also working in this field; G. Karl Almström was investigating pyrrole derivatives and Arthur Bygden organic silicon compounds.

The investigations of Assistant Professor ('docent') Håkan Sandqvist on phenanthrenesulphonic acids may perhaps be regarded as a late extension of the naphthalene work of Cleve and Widman. This field, however, turned out to be a very difficult and tedious one.

Widman retired in 1917 but continued his activities as an experimental scientist for another few years.

Folke Nydal

Folke NydalWith increasing responsibility for education in analytical chemistry as well as examination also on the research level, it was natural to strengthen the position for he head of the laboratory to full professor, which was done in 1963. During this period chairs in analytical chemistry were created at all Swedish universities. This interesting and sudden development of the education, and research in analytical chemistry on the university level may be looked upon as a general interest of the community to improve the conditions for an academic discipline with strong orientation towards practical applications.

Nydahl's research activities are mainly connected with wet chemical analytical techniques and characterised by a profound feeling for solving analytical problems. Together with a number of co-workers Nydahl has improved and developed analytical methods for minerals and rocks with the purpose to secure the standardisation for the more rapid but sometimes less accurate instrumental procedures. Among these investigations may be mentioned chelometric determination of aluminium, calcium and magnesium in the presence of each other (M. Mortsell), the hydrogen peroxide method for spectrophotometric determination of titanium (R. Bryntse), determination of minor amounts of magnesium after separation from calcium by coprecipitation with nickelhydroxide (E. Johansson), extraction of calcium and strontium by coprecipitation (Allan Bengtsson).

Great effort has been made to improve techniques for trace and elementary analysis. To this category of work belong microelementary analysis of selenium (Arthur Bengtsson), determination of trace amounts of sulphur in selenium (B.-L. Sjöborg 1967), determination of microquantities of sulphate sulphur as methyleneblue (L. Gustafsson 1960).

To analytical investigations of more general interest belong separation of sulphate and hydrogen sulphate ions from interfering substances by adsorption on aluminium oxide, prior to sulphate determination (with L. Gustafsson 1953), 4-amino-4'-chlorodiphenyl as an analytical reagent for sulphate (Arthur Bengtsson 1957), the influence of sulphate on the determination of phosphoric acid as molybdophosphate (G.-B. Nordstrom), determination of the solubility products for triphenyltinhydroxide, -fluoride and -chloride as well as the acid constant of triphenyltinaquoion (G. Brodin 1958).

L.-H. Andersson (diss. 1962) carried out a comprehensive investigation of two methods for the determination of silicon as silicic acid and L. Danielsson (diss. 1967) performed a systematic study of the sorption of about thirty metal ions on ion exchangers from solutions containing large amounts of iron. Advanced instrumental techniques were used for the quantitative determinations.

Initiated by the requirements of accurate analytical methods for elements in water (biological research projects in the Baltic) Nydahl and L. Gustafsson have successfully improved some existing methods. One example is the determination of total phosphorus in natural waters (1973). Recently (1976) an important investigation by Nydahl has clarified the reaction parameters at the reduction nitrate - nitrite giving a more accurate determination of nitrate in natural waters.

From the survey of the development in the inorganic department (see p. 73 - 74) it is apparent that some electrochemical work was in progress during the period of 1943 - 1955 under the leadership of E. Blomgren. A certain continuation of this work is represented by a reaction kinetic investigation of organic systems by polarography. This study was performed in the analytical department by R. Tilhage in collaboration with B. Nygård (1964).

Later on, electroanalytical techniques were more consequently introduced in the analytical department. A comprehensive study of some new graphite paste electrodes by J. Lindqvist (diss. 1970) proved the possibility of using this type of electrode for quantitative voltammetric analysis in oxidative processes.

After 24 years as associate and, later, full professor in analytical chemistry, Nydahl retired in 1971. As his successor, Bengt Nygård was appointed.

Bengt Nygård

Bengt NygårdSome of the main problems for a university department of analytical chemistry in the beginning of 1970 can be shortly formulated as follows. The education in different analytical techniques is obvious. The research profile can be given a various extent of connection to certain analytical topics and practical problems or to pure basic methodological studies. Considering the broad scale of techniques incorporated in to-day's analytical chemistry it is also an urgent necessity because of straitened resources to limit the efforts of research to a few specialised fields. Contrary to other universities, the department of analytical chemistry in Uppsala has to its disposal an analytical laboratory working also on a practical base, and economically supported by the faculty of science in common.

In the beginning this unit was anticipated to become a central analytical laboratory for the faculty, actively involved in specific analytical problems included in different external research projects. However, its importance as a central analytical unit has become limited to the same extent, as departments of the faculty with great need of analytical chemistry have created their own analytical service groups. To-day external problems for the central analytical laboratory are found among accurate analysis on standard substances for calibration purposes, in material research, and in determination of special elements (also in trace) in water. Arrangements have been made to concentrate the efforts of the service laboratory to inorganic analytical problems. Recently new investments have improved the equipment for atomic absorption (Fig. 1) and supplied the laboratory with facilities for X-ray fluorescence. In progress is a more systematic study of different methods and development of instrumentation for destruction of organic material in connection with inorganic trace element analysis. The aim of this research project is in first line to develop methods for determination of total amounts of certain elements of interest in the pollution field but at a later stage also to investigate the bonding conditions for trace metals "in vivo".

The basic research in analytical chemistry has so far by different circumstances been given a more independent profile. The earlier research activity of Bengt Nygård was directed towards physical techniques in analytical chemistry. In collaboration with members of the department of organic chemistry, mainly Arne Fredga, Goran Bergson and Lennart Schotte, electroanalytical techniques, especially polarography, had been proven to be a useful tool for studies of redox properties of organic sulphur and selenium compounds. Experiences obtained could confirm the potential possibilities of the voltammetric techniques in organic chemistry for direct analytical purposes as well as for structural correlation of electrochemically measurable parameters. Consequently, a focusing on electroanalytical techniques started in the department during the 1960's was further intensified during the 1970's. As a lucky coincidence a sort of revival of the classical voltammetric techniques came a few years ago. With the help of modern electronics new principles as pulse voltammetry could be realised in commercially available instrumentation of excellent performance. New types of electrodes with graphite as a matrix, e.g. the paste electrode mentioned earlier, could considerably expand the available potential range for voltammetric analysis in anodic direction. Reductive as well as oxidative properties of organic compounds could then be used for electroanalytical purposes.

At the end of the 1960's an instrumental co-operation had started together with the department of electronics. Upon a physicist, Rolf Danielsson who had been established in the department of analytical chemistry, the task was imposed to contribute to the development of instrumentation and techniques of measurement in electroanalytical chemistry. This scientific joint work proved to be very fruitful for improving the instrumental research facilities in the department of analytical chemistry. Danielsson's dissertation in electronics (1973) dealt with the integrated subject "Some examples of electronic instrumentation in analytical chemistry". As a research assistant Danielsson is now responsible for the construction of a new advanced measuring system designed mainly for electroanalytical techniques.

As a specialist on complex chemistry and general solution chemistry Åke Olin entered the department in 1972 as an assistant professor. Also under his responsibility is the development of electroanalytical techniques based on precision potentiometry.

Comprising this introduction means that the research activities are concentrated in three areas within basic and applied electroanalytical techniques namely voltammetry, complex chemistry with potentiometry and instrumental-measuring development. In the following these research projects will be presented in more detail.

Finally it can be mentioned that a limited research program is proceeding in collaboration with industry. One example is physical-chemical investigations of the mechanisms at gel permeation chromatography with special reference to simple inorganic salts. The present capacity of the department for education on the Ph.D. level is about ten students.