21723
The UV absorption spectra of ( S ) - nornicotine was similar to that of ( S ) - nicotine in the range 280 - 220 nm and acidification of the aqueous solution enhanced the absorption .
 Chemical: ( S ) - nornicotine; Chemical: ( S ) - nicotine
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: ( S ) - nornicotine, ( S ) - nicotine 
Answer:
 Chemical: ( S ) - nornicotine; Chemical: ( S ) - nicotine