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: Using two - stage coronary ligation - , digitalis - , and adrenaline - induced canine ventricular arrhythmias , antiarrhythmic effects of cibenzoline were examined and the minimum effective plasma concentration for each arrhythmia model was determined .
### Output Text:
Using two - stage coronary ligation - , <span class="chemical">digitalis</span> - , and <span class="chemical">adrenaline</span> - induced canine ventricular arrhythmias , antiarrhythmic effects of <span class="chemical">cibenzoline</span> were examined and the minimum effective plasma concentration for each arrhythmia model was determined . 