title: Gas chromatographic-mass spectrometric identification of phenylurea herbicides after N-methylation.
mesh_terms: D002849:Chromatography, Gas; D006540:Herbicides / Q000032:analysis*; D013058:Mass Spectrometry; D008745:Methylation; D010671:Phenylurea Compounds / Q000032:analysis*
chemical_list: D006540:Herbicides; D010671:Phenylurea Compounds