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: Oxidative damage precedes nitrative damage in adriamycin - induced cardiac mitochondrial injury .
### Output Text:
Oxidative damage precedes nitrative damage in <span class="chemical">adriamycin</span> - induced cardiac mitochondrial injury . 