Fritz Pregl was born in 1869, in Laibach, Austria (now Ljubljana, Republic of Slovenia), the only son of Friderike Schlacker and Raimund Pregl. Pregl earned his medical degree from the University of Graz in 1893; while he practiced medicine, he stayed at the university working in a chemistry laboratory. Pregl's interests turned towards organic chemistry and in 1904, he went to Germany to study chemistry with Friedrich Wilhelm Ostwald in Leipzig and Emil Fischer in Berlin. Fischer was a 1902 Nobel laureate in organic chemistry for his sugar and purine research, and Ostwald, a physical chemist, would win the Nobel in 1909 for his work in catalysis.
Returning to Graz in 1905, Pregl renewed his prior research in bile and began protein investigations, having been intrigued by Fischer's recent work on the structure of proteins. In the course of his chemical investigations, Pregl continually came up against one problem: the methods of analysis employed by organic chemistry were much too cumbersome, lengthy, and overly complex for the new discipline of biochemistry in which he was becoming increasingly involved. In particular, Pregl found that he would have to prepare large amounts of test samples if he used traditional analytical methods in his studies on bile acids. Because these acids are complicated proteins, only small quantities can be isolated from liver bile, a process that is both time-consuming and costly: Pregl's research in bile acid alone would require processing several tons of raw bile in order to refine enough of the acid for traditional analysis. It was to overcome such difficulties that he set to improve the methods of microanalysis, thereby altering the direction of his research from biochemistry to analytical chemistry.
By the time Pregl entered the field, microanalysis was already over 70 years old, pioneered by Justus von Liebig, who had developed the combustion method. Additionally, a contemporary of Pregl's, Friedrich Emich, had shown the reliability of working with small quantities of substances in an inorganic framework. Pregl set out to achieve Emich's measurement techniques with organic material.
It was Pregl's achievement to build upon Liebig and Emich's developments, and to refine and improve them to the point where substantially less of the organic substances were required for analysis. In 1910 he left Graz for Innsbruck, where he took the position of professor of medical chemistry at the University of Innsbruck. His first priority was to find or create a balance that would accurately weigh much smaller amounts of substances than those currently available. He turned to W. H. Kuhlman, a German chemist who had recently developed a microbalance accurate to between 0.01 and 0.02 milligrams; Pregl found that with careful adjustments he could accurately utilize Kuhlman's balance to within 0.001 milligrams.
Pregl also took on the combustion analysis of carbon and hydrogen, improving that process by scaling down the size of the analytic equipment and adding a universal filling for the combustion tube that consisted of a mixture of lead chromate and copper oxide set in between two pieces of silver. This adaptation improved the absorption of the carbon dioxide and water. With such refinements, Pregl was able to obtain accurate analyses with between 2-4 milligrams of an organic substance--and fairly accurate readings with only 1 milligram--a significant reduction compared to the.2 to 1 grams needed for Liebig's method. With the new materials employed, Pregl was also able to reduce the time needed for such analysis from three hours to an hour. Pregl and his team also went on to devise new microanalytic techniques for boiling substances to determine their molecular weight by creating apparatus that impeded the substances' contamination with air. This allowed determinations to be made with greatly reduced amounts of such substances.
Although improved techniques since Pregl's time now allow scientists to work with organic samples of only a few tenths of a milligram, his microanalytic improvements were revolutionary in their day and opened the way to new vistas of biochemical research in both science and industry. World renowned, Pregl returned to the University of Graz in 1913 as a full professor at the Medicochemical Institute, and here he perfected the methods he had pioneered, remaining in Graz--despite other tantalizing offers--until his death.
In 1923 Pregl was awarded the Nobel Prize in chemistry for his advances in microanalysis of organic substances. Though his work was an improvement rather than an invention, it was a well deserved honor for a man who tirelessly devoted his life to the cause of science. A life-long bachelor, Pregl was devoted to his students, lending both money and support when needed. In 1929 he endowed an award for chemistry through the Vienna Academy of Sciences, the Fritz Pregl Prize, which continues to provide yearly stipends to promising students. Pregl died following an illness in 1930 at the age of 61.
This is the complete article, containing 793 words
(approx. 3 pages at 300 words per page).
