26506
The results of a study on levels of perfluorooctane sulfonate ( PFOS ) and perfluorooctanoic acid ( PFOA ) , analysed by HPLC - ESI - MS , in human milk and food samples from the city of Siena and its province ( central Italy ) are here reported .
 Chemical: perfluorooctane sulfonate; Chemical: PFOS; Chemical: perfluorooctanoic acid; Chemical: PFOA
Given options, please tell me the categories of all the listed entity words.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
 Entities: perfluorooctane sulfonate, PFOS, perfluorooctanoic acid, PFOA 
Answer:
 Chemical: perfluorooctane sulfonate; Chemical: PFOS; Chemical: perfluorooctanoic acid; Chemical: PFOA