Atrazine production

Generic producers and a number of companies registered and sold technical atrazine under their own trade names to other formulators. There are more than 140 atrazine products in the United States sold by 41 companies. 

Figure 32.2 Examples of BMPs included on atrazine product labels. From Syngenta Crop Protection (2005).

Table A5 Examples of label changes implemented for Syngenta atrazine products...

Mitigation for tile-outlets in terraced fields for atrazine products... 

This large volume indicates that there is cither no health problem or there is considerable uncertainty (i.e., the product of the uncertainty factors is large) in estimating a reference dose for atrazine. 

Atrazine is a widely used triazine which can degrade to several products, including deisopropylatrazine (DIA), deethylatrazine (DEA) and hydroxyatrazine (HA). These species are highly polar and their determination by GC requires a derivatiza-tion step. LC methods combined with SPE (off-line or on-line) are therefore the ones which are most commonly used. The LC-LC method proposed in the literature (34) can allow low levels to be detected with a small sample volume. The experimental conditions are shown in Table 13.1. Due to the different polarity between the most... 

The product-ion spectra of the (M - - H)+ ions of atrazine, the structure of which is shown in Figure 3.29, and three of its transformation products showed that if the isopropyl side-chain was present in the structure a constaut neutral... 

Figure 3.29 Structure of atrazine. Reprinted from J. Chromatogr., A, 915, Steen, R. J. C. A., Bobeldijk, I. and Brinkman, U. A. Th., Screening for transformation products of pesticides using tandem mass spectrometric scan modes , 129-137, Copyright (2001), with permission from Elsevier Science.

The TIC trace from the LC-MS analysis of an extracted river water sample, spiked with 3 p.g dm of atrazine and three of its degradation products, is shown in Figure 3.30. The presence of significant levels of background makes confirmation of the presence of any materials related to atrazine very difficult. The TIC traces from the constant-neutral-loss scan for 42 Da and the precursor-ion scan for m/z 68 are shown in Figure 3.31 and allow the signals from the target compounds to be located readily. 

Atrazine is successively transformed to 2,4,6-trihydroxy-l,3,5-triazine (Pelizzetti et al. 1990) by dealkylation of the alkylamine side chains and hydrolytic displacement of the ring chlorine and amino groups (Figure 1.3). A comparison has been made between direct photolysis and nitrate-mediated hydroxyl radical reactions (Torrents et al. 1997) the rates of the latter were much greater under the conditions of this experiment, and the major difference in the products was the absence of ring hydroxylation with loss of chloride. 

Combined treatment of atrazine with ozone and H2O2 resulted in retention of the triazine ring, and oxidative dealkylation with or without replacement of the 2-chloro group by hydroxyl (Nelieu et al. 2000). Reaction with ozone and hydroxyl radicals formed the analogous products with the additional formation of the acetamido group from one of the N-alkylated groups (Acero et al. 2000). 

Acero JL, K Stemmier, U van Gunten (2000) Degradation kinetics of atrazine and its degradation products with ozone and OH radicals a predictive tool for drinking water treatment. Environ Sci Technol 34 591-597. 

This example illustrates the difficulty of showing pesticides mutagenic activity. For example, mutagenic activity was clearly expressed not in the sym-triazine herbicides atrazine and cyanazine, but in their transformation products formed in corn husks ... 

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