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: Hepatic dysfunction may be one of the possible risk factors , and concomitant fever may be a diagnostic marker for adverse reaction to quetiapine .
### Output Text:
Hepatic dysfunction may be one of the possible risk factors , and concomitant fever may be a diagnostic marker for adverse reaction to <span class="chemical">quetiapine</span> . 