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: OBJECTIVE : To present a case of fluconazole - associated torsade de pointes ( TDP ) and discuss fluconazole ' s role in causing TDP .
### Output Text:
OBJECTIVE : To present a case of <span class="chemical">fluconazole</span> - associated torsade de pointes ( TDP ) and discuss <span class="chemical">fluconazole</span> ' s role in causing TDP . 