Phenoxyacetic acids herbicide mobility

Mobile phases Eor RP-LC, mixtures of an aqueous component and organic solvents are invariably used. The aqueous component is eventually buffered (e.g., phosphate buffers l-10mmoll for triazines and phenylureas) or acid additivated (e.g., 0.1% phosphoric acid for chlorophenoxy acidic herbicides or 0.1-0.4% for phenoxyacetic herbicides). The organic solvents are mainly methanol, acetonitrile, or their mixtures. For NP-LC, hexane, dichloromethane, ethanol, and iso-propanol are frequently used. 

Other herbicidal phenoxyacetic and phenoxypropionic acids have some properties similar to those of (2,4-dichlorophenoxy)acetic acid, but often have quite different species selectivity. Some of the differences can be explained on the basis of molecular stability, persistence, or mobility in the toxic form, as well as on the basis of differences in solubility and in absorption through leaves or roots. 

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