2108
Fentanyl citrate ( 0 . 1 mL ) and 2H5 - fentanyl ( internal standard , 0 . 05 mL , 100 mg / L ) were extracted with Toxi - A tubes ( Toxi - Lab , Irvine , CA ) and analyzed by gas chromatography - mass spectrometry .
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Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: GENE 
Text: {0} 
Answer:
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