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: A challenge dose of quinidine caused clinical symptoms and abrupt elevation of SGOT , alkaline phosphatase , and lactic acid dehydrogenase values .
### Output Text:
A challenge dose of <span class="chemical">quinidine</span> caused clinical symptoms and abrupt elevation of SGOT , alkaline phosphatase , and <span class="chemical">lactic acid</span> dehydrogenase values . 