26555
Recoveries at three spiked levels ( 10 , 50 , 100ng / g ) in random selected food matrices were in range of 71 - 121 % with RSDs not larger than 25 % .
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Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: Chemical 
Text: {0} 
Answer:
 None