3010
Since we wanted to focus on sub lethal ion - osmoregulatory and respiratory disturbances , arterial blood samples were analysed for pH ( a ) , PaO ( 2 ) , haematocrit and total CO ( 2 ) values at several time points .
 Chemical: CO ( 2 )
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: CO ( 2 )