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: We report the case of a 19 - year - old Laotian patient affected by fulminant hepatitis during the third trimester of her pregnancy after a 1 - month administration of quinidine phenylethylbarbiturate .
### Output Text:
We report the case of a 19 - year - old Laotian patient affected by fulminant hepatitis during the third trimester of her pregnancy after a 1 - month administration of <span class="chemical">quinidine phenylethylbarbiturate</span> . 