Sören Jensen is best known for his groundbreaking work in 1966, where he discovered and identified polychlorinated biphenyls (PCBs) in environmental samples from Sweden. This discovery was a result of an unexpected finding during the analysis of the pesticide DDT, where unknown substances appeared on the sample chromatograms. Using the advanced mass spectrometry technology, Jensen identified these unknown compounds as PCBs, a group of industrial chemicals widely used at the time.

Professor Jensen's discovery led to a global awareness of highly toxic PCBs contaminating the environment. In response, Sweden banned the use of PCBs in 1972, and other countries followed suit. PCBs remain a significant environmental contaminant due to their persistence and ability to accumulate in living organisms.

Professor Emeritus Sören Jensen. Photo: Private

Sören Jensen made significant contributions to the field of environmental chemistry throughout his career. He started at Stockholm University's Department of Analytical Chemistry and later led the Swedish EPA’s Special Analytical Laboratory at the multidisciplinary Wallenberg Laboratory where he became a professor in the Environmental Chemistry Unit that later became the Department of Environmental Chemistry. In his later years, he served as Professor Emeritus at the Department of Environmental Science. Sören's work on PCBs laid the foundation for our department's research approach, which involves developing new analytical chemistry methods, searching for new chemicals and their metabolites in environmental samples, collaborating with experts from various fields, assessing the impact of chemicals on humans and the environment, and advocating for the regulation of hazardous substances.

Sören was known for his vision, creativity, and generous assistance in analytical methods development. Even in his late 80s, he remained active in our department, leaving an enduring mark on our research. 

We will deeply miss him, and his legacy will continue to influence the field of environmental science. 

Read an interview with Professor Sören Jensen