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: None of the animals that received bupivacaine , normal saline , or normal saline titrated to a pH 3 . 0 developed hind - limb paralysis .
### Output Text:
None of the animals that received <span class="chemical">bupivacaine</span> , normal saline , or normal saline titrated to a pH 3 . 0 developed hind - limb paralysis . 