21192
Acid dissociation constants ( pKa ) were determined , the effect of functional surfactant alkyl chain length and pH on the observed rate constant ( kobs ) for phosphate ester cleavage has been discussed , and the effect of substrate on the supernucleophilicities of the studied oximes was monitored .
 Chemical: alkyl; Chemical: phosphate ester; Chemical: oximes
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: alkyl; Chemical: phosphate ester; Chemical: oximes