Determination of ametryn herbicide by bioassay and gas chromatography-mass spectrometry in analysis of residues in drinking water - Queiroz, Regina Helena Costa; Lanchote, Vera Lúcia; Bonato, Pierina Sueli; Tozatto, Eduardo; Carvalho, Dermeval de; Gomes, M. A.; Cerdeira, Antonio Luiz (Bolletino Chimico Farmaceutico, 1999)