Izaak Maurits Kolthoff (Father of Analytical Chemistry]) (February 11, 1894 - March 4, 1993) was a highly influential chemist

Chemist

A chemist is a scientist trained in the study of chemistry. Chemists study the composition of matter and its properties such as density and acidity. Chemists carefully describe the properties they study in terms of quantities, with detail on the level of molecules and their component atoms...

, widely considered the Father of Analytical Chemistry

Analytical chemistry

Analytical chemistry is the study of the separation, identification, and quantification of the chemical components of natural and artificial materials. Qualitative analysis gives an indication of the identity of the chemical species in the sample and quantitative analysis determines the amount of...

. He was given this title based on his development of analytical chemistry as a modern science. His research dealt with analytical and physical chemistry. His main research topics included potentimetry, conductometry, polarography, theory and application of indicators, acid-base equilibria and titrations in aqueous and non-aqueous media, formation, properties and aging of precipitates, adsorption, coprecipitation, post-precipitation, and induced reactions. He is also credited in development of the polarograph, an instrument for recording polarization of electrolytes. During World War II he served as chairman of the Committee on Analytical research Methods and supervisor of three research projects for the U.S. Government on synethic or "cold process" rubber.

Dr. Kolthoff believed that fundamentals of physical chemistry, biochemistry, and pharmaceutical chemistry should also apply to analytical chemistry, and by doing so further developed the then artful analytical chemistry by applying these fundamentals to analytical processes. Motto:”Theory guides, experiment decides.”

Background

Izaak Kolthoff was the son of Moses and Rosetta Kolthoff was born in Almelo, Netherlands. He is the youngest of three children. During his early education in high school, his first chemistry course allowed him to develop a keen interest in the subject. This inspired him to create his own laboratory in his kitchen. Some of his experiments involved hydrogen sulfide to the dismay of his family. After graduating from high school in 1911 he entered the School of Pharmacy at the University of Utrecht. The reason he began his studies in pharmacy rather than chemistry was that he lacked Latin and Greek, which at that time were prerequisites for admission to the "pure" physical sciences. Nevertheless, the pharmacy curriculum at Utrecht was thorough and involved a great deal of analytical chemistry. Kolthoff's pharmacy professor,
Nicholas Schoorl, was a great influence in his life. Schoorl emphasized a proper balance between descriptive chemistry and the fundamental principles of the field. He was an important part of Kolthoff’s life education. Schoorl drew Kolthoff’s attention to early papers in electro-analytical chemistry as well as co-precipitation. He was also responsible for advising Kolthoff to study analytical chemistry from a scientific perspective as opposed to an empirical art. Upon graduation, Kolthoff obtained an “apotheker” dimploma in 1915. He continued his education by taking more courses at Utrecht in physical and colloid chemistry. By 1918, the University had dropped its requirement for Latin and Greek and he received a Ph.D. in chemistry.

After college, Izaak Kolthoff was known for his originality, insight and timeliness of his published work. Kolthoff published his first paper in 1915 on pH, a new concept at the time. By 1918 he had already published 32 papers. From 1924-1927 he authored or coauthored eight textbooks and monographs. At his time of retirement, he had published 809 research papers and nine textbooks published. Over the next thirty years he published another 136 papers. From 1959 to 1980 he coedited thirty four volumes of reference books. Kolthoff continued his stay at Utrecht as a conservator and then as a lecturer in electrochemistry. In 1924, he was invited on a lecture tour in Canada and the United States. He also served as chairman of the Committee on Analytical Research Methods and supervisor of three research projects for the U.S. Government on synthetic rubber. This work was specifically about the emulsion polymerization process. This was a crucial step to the military for making synthetic rubber as natural rubber supplies had been stopped. He was also considered a political and social justice activist. In the early 1950s, the Un-American Activities Committee accused Kolthoff of belonging to thirty two subversive organizations. This was directly after he criticized Senator Joseph McCarthy’s persecution of perceived communists. No actions was taken against him. Also, he helped German scientist persecuted by Hitler to find jobs at the University of Minnesota.

Kolthoff never married and lived most of his life a short distance from the Chemistry building. After retirement, he continued working with his lab assistant Miron Chantooni. He died on a Thursday at Bethesda Lutheran Hospital and Rehabilitation Center in St. Paul, and ,according to his trustee Sidney Barrows, his death was due to kidney failure.

Occupation

In 1924, Kolthoff went on a lecture tour in the United States and Canada. Soon after, he was offered a position as professor and chief of the Analytical Division of the School of Chemistry at the University of Minnesota in 1927. Initially, he had a contract for just one year but his position there became permanent. In his letter of acceptance he stated, “I may assure you that [on] my side I will try to do my duty as well as possible and I hope that your expectations will not be disappointed. He remained at the University of Minnesota until he nominally retired in 1962. After he retired, he remained active in research until the late 1980s.

Membership

Kolthoff was a member of many honorary groups. These included the National Academy of Sciences. He was also a Fellow of the American Academy of Arts and Sciences, an honorary member of the American Pharmaceutical Association, and an honorary member of eight foreign chemical societies.

Degrees and Awards

He received many Honorary Doctor of Science degrees from the University of Chicago, the University of Groningen, Brandeis University, and the Hebrew University of Jerusalem. He received these awards from each of the universities in 1955, 1964, 1974, and 1975, respectively. Also, the Netherlands Government knighted him in 1947 as a Commander in the Order of Orange-Nassau. The American Chemical Society recognized Dr. Kolthoff for his work in modern analytical chemistry, awarding him with the William H. Nichols Medal in 1949. He also received the Robert Boyle Medal from the Royal Society of Chemistry in England, the Charles Medal of the Charles University in Prague, and the Fisher Award, among other awards and medals. On his eightieth birthday, the Division of Analytical Chemistry of the American Chemical Society sponsored the I.M. Kolthoff 80th Anniversary Symposium. The Regents of the University of Minnesota named the new chemistry research building Kothoff Hall in 1972 in his honor.

Research

The main areas of research were as diverse as they were full of insight. The main areas of his research were pH, Electron transfer, precipitation reactions, voltammetry, emulsion polymerization, induced reactions, compounds containing sulfhydryl and disulfide groups, and nonaqueous solutions.

“Proton transfer reactions in analytical chemistry: the pH concept, titrations, indicators, and buffers”

Proton transfer reactions in analytical chemistry: the pH concept, titrations, indicators, and buffers was Dr. Kolthoff’s first paper. It dealt with the titration of phosphoric acid as a mono- and diprotic acid.

“Electron transfer and precipitation reactions”

This topic arose from his thesis work on the fundamentals of iodimetry. In this work he discussed the variety of reactions occurring in iodimetry, the mechanisms of these reactions, side reactions, and titration errors.

“Formation and properties of precipitates”

Dr. Kolthoff spent much time with precipitates. He discovered many new things about crystalline precipitates. He used radiotracers, thorium B for lead and bromine activated by neutrons from a radon-beryllium source to study the highly imperfect crystalline precipitates. These structures underwent aging when above ambient temperatures, meaning purification by recrystallization takes place.

“Voltammetry”

J. Heyrovsky was the inventor of polarography and introduced the topic to Kolthoff in 1933. Polarography is the measurement of voltammetry at the dropping mercury electrode. Two of Kolthoff’s students began working on voltammetry.

“Emulsion Polymerization”

Dr. Kolthoff was asked to work with the major rubber companies to create a synthetic rubber for the war effort. He was asked to develop analytical methods so that the rates at which reactants were consumed could be determined. N-dodecyl mercaptan was a constituent that turned out to be key reactant. It is referred to as OEI for “one essential ingredient.” Dr. Kolthoff developed a method for the determination of OEI based on amperometric titration at the rotated platinum microelectrode with silver nitrate. His method found worldwide use after the war. Immediately after this research, Dr. Kolthoff looked into factors influencing the rates of reaction of mercaptans. He also studied the kinetics and mechanism of emulsion polymerization in general. This later led to initiating systems that worked at lower temperatures and produced “cold rubber.” “Cold rubber” had superior properties to natural rubber.

“Induced Reactions”

Dr. Kolthoff studied a number of induced reactions, including the iron(II)-hydrogen peroxide reaction, and showed that hydroxyl radicals in the first step can induce the oxidation of many organic compounds.

“Compounds containing sulfhydryl and disulfide groups”

He also underwent extensive studies that included compounds containing sulfhydryl and disulfide groups starting in 1950. The papers may be the first in bioelectrochemistry.

“Chemistry of nonaqueous solutions.”

In the early 1950s, Dr. Kolthoff began a long series of studies on how solvents influence the properties of solutes. The contributions of proton transfer followed by electrolytic dissociation were resolved by these studies. He also became interested in reactions of macrocyclic ligands in various solvents.

Der Gebrauch von Farbenindikatoren (1922)

His first published monogram. This book went through many German editions and then was translated into English at Princeton University. It was later titled Acid-Base Indicators after being expanded in 1937 with C. Rosenblum as coauthor.

Konduktometrische Titrationen and Potentiometric Titrations

During the period when he was working on iodimetry, he began to use conductometry and poteniometry which led to these two monograms. Potentiometric Titrations was especially influential, not only in analytical chemistry, but in other fields as well.

Massanalyse

This was a continuation of his fundamental studies of classical methods. It was translated and coauthored by N.H. Furman. It later appeared in 1928 as Volumetric Analysis. It also appeared much later (1942–1958) in an expanded three-volume edition coauthored by V.A. Stenger, G. Matsuyama, and R. Belcher. Dr. Kolthoff served as adviser to Maurits Dekker and Eric Proskauer in creating Interscience Publishers.

Emulsion Polymerization

This book immediately followed Dr. Kolthoff’s studies on “cold rubber.” It was coauthored with F.A. Bovey, A.I. Medalia, and E.J. Meehan.

The Colorimetric and Potentiometric Determination of pH

The Colorimetric and Potentiometric Determination of pH was Dr. Kolthoff’s first book and was published in 1931. It was mostly meant to be used as text.

Textbook of Quantitative Inorganic Analysis

This was his second text published. It was considered to have an “admirable balance between the fundamentals and the experimental features of the field.” This book served as a model for future texts.

Treatise on Analytical Chemistry

This is said to be his most monumental production. Part I deals with the general fundamentals of analytical chemistry. Part II deals with the analytical chemistry of organic and inorganic compounds in more specific terms. Part III concerns analytical chemistry in industry. The Treatise had a huge impact on the world and is the principal reference source of analytical chemistry.