Protonation and Degradation Reactions ofs-Triazine Herbicides

Water, chloroform, acetonitrile, and atrazine adsorption to the amorphous silica surface studied by vibrational sum frequency generation spectroscopy

“…However, a weak and broad peak is observed at $2900 cm À1 and is assigned to the atrazine CH stretching modes revealing that atrazine is adsorbed to the silica surface. At pH $ 6.5, atrazine is a neutral molecule (pKa 1 = 1.65 and pKa 2 = 1.95) [43] and the silica surface is mostly terminated with silanol groups. This suggests that atrazine is physisorbed to silanol groups and/or surface water.…”

Catalytic effect of transition metals on microwave-induced degradation of atrazine in mineral micropores

“…Sorption of atrazine on all the solids followed the Freundlich-type isotherm, while the presence of copper and iron enhanced its sorption on the zeolites, particularly in the low aqueous concentration range. With a pKa 1 of 1.60 and a pKa 2 of 1.95 (Colombini et al, 1998), atrazine adsorbs on mineral surfaces as neutral species at circumneutral pH. Displacement of the loosely bound water from the hydrophobic micropore space was believed to be the major mechanism of atrazine sorption on microporous minerals (Cheng and Reinhard, 2007;Hu et al, 2012;Hu and Cheng, 2013a).…”

Electrochemical behavior of parent and photodegradation products of some selected pesticides

“…De-ethylatrazine has been shown to be electroactive, 20 but its reduction potential is too close to atrazine and can not be separated from the reduction peak of atrazine in a differential pulse polarogram. However, as production of the de-ethyl-atrazine and de-isopropyl-atrazine is very low in the photolysis process, the reduction peak observed in Figure 4a can be basically attributed to atrazine.…”

“…A degradation product of the herbicide propanil, 11 3-4-dichloroaniline (DCA), generated by enzymatic or chemical hydrolysis or photolysis, presented an oxidation peak at +0.66 V, allowing its determination in the presence of propanil which has an oxidation peak at +1.27 V, with no peak overlapping. Electrochemical behavior of desethyl atrazine and desethyl terbutylazine, the desethylated degradation products of atrazine and terbutylazine were evaluated by polarography, 20 showing different pH dependences in their reduction processes.…”