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: CONCLUSIONS : Delirium was found in 10 % of clozapine - treated inpatients , particularly in older patients exposed to other central anticholinergics .
### Output Text:
CONCLUSIONS : Delirium was found in 10 % of <span class="chemical">clozapine</span> - treated inpatients , particularly in older patients exposed to other central anticholinergics . 