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: Syncope caused by hyperkalemia during use of a combined therapy with the angiotensin - converting enzyme inhibitor and spironolactone .
### Output Text:
Syncope caused by hyperkalemia during use of a combined therapy with the <span class="chemical">angiotensin</span> - converting enzyme inhibitor and <span class="chemical">spironolactone</span> . 