4447
A headspace - solid phase microextraction - gas chromatography - mass spectrometric ( HS - SPME - GC - MS , hereafter abbreviated as " SPME " ) method was developed for dedicated organophosphorus ( OP ) pesticides assessment in multiple vegetable and fruit commodities .
 organophosphorus
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: Chemical 
Text: {0} 
Answer:
 organophosphorus