17137
Good recoveries ( 95 . 2 - 101 % ) were obtained by the standard addition method on four samples with high repeatability ( RSD , 0 . 8 - 3 . 4 % ) .
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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:
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