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Cells were exposed to a H2S donor , sodium hydroxysulfide ( NaHS ) , at pH 6 . 0 , 7 . 0 , or 8 . 0 for 1 h at 37 degrees C in a sealed conical tube to avoid the loss of dissolved H2S gas .
 Chemical: H2S; Chemical: sodium hydroxysulfide; Chemical: NaHS; Chemical: H2S
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: H2S; Chemical: sodium hydroxysulfide; Chemical: NaHS; Chemical: H2S