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: Plasma cortisol concentrations were significantly raised during the active phase ( 323 + / - 43 to 1082 + / - 245 mmol / L , P < 0 . 05 ) .
### Output Text:
Plasma <span class="chemical">cortisol</span> concentrations were significantly raised during the active phase ( 323 + / - 43 to 1082 + / - 245 mmol / L , P < 0 . 05 ) . 