23448
The formazan precipitation was found to be proportional to the TiO2 concentration , being enhanced under laboratory daylight exposure .
 Chemical: formazan; Chemical: TiO2
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: formazan; Chemical: TiO2