Analyse separately, fight together The Norwegian toxicologists then went a step further and asked Braun's colleagues at the University of North Dakota to isolate the soot particles from the adherent chemical toxic substances using solvents. Braun then analysed the components individually under X-ray light: first the "bare" soot particles, then the solution with the suspected carcinogenic chemicals previously bound to the soot. Braun again found various functional groups on the carbon structure and was able to compare them with the findings of his earlier work. At the same time, the toxicologists tested the effect of the two soot fractions on human lung cells in culture. For the first time separate investigations had been carried out to establish what is so dangerous in soot. The study, which recently appeared in the journal "Toxicology Letters", is, in Braun's opinion, the first to combine the methods of X-ray absorption spectroscopy (NEXAFS) with toxicological methods. |