Separation and detection methods of fluorescent whitening agent in expanded polystyrene

The invention provides a separation method of a fluorescent whitening agent in expanded polystyrene. The separation method is characterized by at least comprising following steps: (1), expanded polystyrene is smashed and dissolved by an organic solvent, and a solution containing expanded polystyrene is obtained; (2), a sulfonating agent is added to the solution containing expanded polystyrene for sulfonating treatment, and sulfonated expanded polystyrene and a sulfonated fluorescent whitening agent are produced; (3), water is adopted for extraction, an aqueous phase is collected and filtered, and a sulfonated fluorescent whitening agent solution is obtained.