28459
From such FTIR data , we are able to closely monitor the degree of protonation along the polymer chain as well as revealing information concerning the D2O concentration at the interface .
 Chemical: D2O
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: D2O