6254
The C , N , O , and S isotopic compositions of egg components from 7 different production systems were measured .
 Chemical: C; Chemical: N; Chemical: O; Chemical: S
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: C; Chemical: N; Chemical: O; Chemical: S