Spectroscopic properties of the methyl esters of chlorophenoxy acid herbicides.

The mass and infrared spectra of the methyl esters of 9 chlorophenoxy acid herbicides are presented. Ultraviolet data are discussed and proton magnetic resonance spectra are tabulated. Because of the sensitivity of the technique, the mass spectra are most useful for the identification of those compounds in residues, especially by combined gas chromatography-mass spectrometry. The pure herbicides used for the recording of the spectra were obtained by synthesis and recrystallization.