Analytical Method for Measuring SBR Tire Debris in the Environment

A procedure has been developed for assaying submilligram amounts of debris from synthetic tire tread rubber in aerosol samples collected from the atmosphere. The procedure involves separation from the bulk of the sample by Soxhlet extraction with orthodichlorobenzene in a stream of oxygen, followed by infrared spectroscopic determination of the rubber hydrocarbon SBR (styrene-butadiene copolymer) in the extract. The procedure was developed to overcome serious difficulties having to do with the small amounts of rubber normally encountered and with losses of SBR during extraction from aerosol samples. These matters are discussed in some detail and some applications of the method are illustrated.