was undertaken.Reagents. Commercial solid n-tetradecyl-and n-dodecylamines (Aldrich) and liquid n-butylamine were purified by vacuum distillation. Reagent grade dimethylamine (Eastman) was used without further purification. A 20% aqueous solution of methylamine was used for the preparation of the methylamine salt. Commercial 2,4-D (Aldrich) was recrystallized from benzene until a constant melting point of 140.3 ± 0.5°was attained.1:1 salts of 2,4-D were made by adding stoichiometric amounts of the amines dissolved in benzene-acetone solutions to solid 2,4-D at 10°. The solutions were shaken until all the 2,4-D had disappeared. The solvent was removed under vacuum at room temperature. The resultant salts were recrystallized from 1:1:1 ether-acetone-hexane until the melting points were constant.EXPERIMENTAL SECTION Pyrolysis Experiments. The solid salts were pyrolyzed in sealed Pyrex tubes covered with aluminum foil. Separate samples were pyrolyzed for 1 hr at temperatures from 30 to 200°. The tubes were then cooled before recording mass, infrared, and nuclear magnetic spin resonance spectra of the products.
2,4-D levels in the South Saskatchewan River near Saskatoon in 1973 at the height of the spraying season, and at harvestime, were determined by a method involving direct glc analysis, ankaline hydrolysis, followed by n-butylation of the liberated free acid after acidification of the alkaline solution, and confirmed by subsequent n-octylation. GC/MS also confirmed the presence of 2,4-D. 2,4-D was detected during the spraying season but not at harvest time or in river mud samples. The average level was ca. 2mug of acid equivalent to 2,4-D per liter of river water at the height of the spraying season.
Purity of Reagent Grade p-and o-Chlorophenoxyacetic Acids and Its Biological Implications Reagent grade p-and o-chlorophenoxyaceticThe level of 2,4-D may account for the biological acids contain phenolic (<0.2%) and 2,4-dichloro-
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