23168
( 18 ) O isotope exchange depth profiling with ToF - SIMS was employed to simultaneously measure the tracer surface exchange coefficient k * and the tracer diffusion coefficient D * in the temperature range 280 - 475 degrees C .
 Chemical: ( 18 ) O
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: ( 18 ) O