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: Other ECG parameters before the application of d , l - sotalol did not identify patients at increased risk for torsades de pointes .
### Output Text:
Other ECG parameters before the application of <span class="chemical">d , l - sotalol</span> did not identify patients at increased risk for torsades de pointes . 