17462
Iron ( III ) was reduced to iron ( II ) by ascorbic acid and preconcentrated on a mini - column packed with polyurethane foam ( PUF ) functionalized with N , N - bis ( salicylidene ) - 1 , 3 - propanediamine ( SPDA ) .
 Chemical: Iron ( III ); Chemical: iron ( II ); Chemical: ascorbic acid; Chemical: polyurethane; Chemical: N , N - bis ( salicylidene ) - 1 , 3 - propanediamine; Chemical: SPDA
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
Answer:
 Chemical: Iron ( III ); Chemical: iron ( II ); Chemical: ascorbic acid; Chemical: polyurethane; Chemical: N , N - bis ( salicylidene ) - 1 , 3 - propanediamine; Chemical: SPDA