When the reaction is complete, {HEAD ~ the solvent layer} containing the leuco dye is isolated and treated with {TAIL ~ a decolorizing agent}, e.g., Attapulgus clay 
When the reaction is complete , { HEAD ~ the solvent layer } containing the leuco dye is isolated and treated with { TAIL ~ a decolorizing agent } , e.g. , Attapulgus clay
OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH REL OTH OTH REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH