21938
Inhibition of citral degradation in an acidic aqueous environment by polyoxyethylene alkylether surfactants .
 Chemical: citral; Chemical: polyoxyethylene alkylether
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: citral, polyoxyethylene alkylether 
Answer:
 Chemical: citral; Chemical: polyoxyethylene alkylether