In the sentence extracted from biomedical literature, identify all the chemical entities. The required answer format is the same sentence with HTML <span> tags to mark up specific entities. 
### Entity Markup Guides:
Use <span class="chemical"> to denote a chemical.

### Input Text: BACKGROUND : This study examined the role of phase 2 early afterdepolarization ( EAD ) in producing a trigger to initiate torsade de pointes ( TdP ) with QT prolongation induced by dl - sotalol and azimilide .
### Output Text:
BACKGROUND : This study examined the role of phase 2 early afterdepolarization ( EAD ) in producing a trigger to initiate torsade de pointes ( TdP ) with QT prolongation induced by dl - <span class="chemical">sotalol</span> and <span class="chemical">azimilide</span> . 