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: Rats were given a single dose of adriamycin and one month later divided into four groups matched for albuminuria , blood pressure , and plasma albumin concentration .
### Output Text:
Rats were given a single dose of <span class="chemical">adriamycin</span> and one month later divided into four groups matched for albuminuria , blood pressure , and plasma albumin concentration . 