S-triazine herbicides, atrazine

Kulshrestha, G., N.T. Yaduraju, and V.S. Mani. 1982. The relative toxicity of the s-triazine herbicides atrazine and simazine to crops. Jour. Environ. Sci. Health B17 341-354. 

Mandelbaum, R.T., D.L. Allan, and L.P Wackett (1995). Isolation and characterization of a Pseudomonas sp. that mineralizes the s-triazine herbicide atrazine. Appl. Environ. Microbiol., 61 1451-1457. 

Wang, Y.-S., J.-R. Duh, Y.-F. Liang, and Y.-L. Chen (1995). Dissipation of three s-triazine herbicides atrazine, simazine, and ametryn in subtropical soils. Bull. Environ. Contam. Toxicol., 55 351-358. 

The toxic effects of some pesticide mixtures are additive, particularly when their toxic mechanisms are identical. The additive effects of the organophosphates chlorpyrifos and diazanon were demonstrated in one study. T Another study found the s-triazine herbicides atrazine and cyanazine to show additive toxic effects. Not all mixtures of similar pesticides produce additive effects, however. In one study, mixtures of five organophos-phate pesticides (chlorpyrifos, diazinon, dimethoate, acephate, and malathion) were shown to produce greater than additive effects when administered to laboratory animals. Another article discusses nonsimple additive effects of pyrethroid mixtures. Despite the similarities in their chemical structure, pyrethroids act on multiple sites, and mixtures of these produce different toxic effects. 10 ... 

Pelizzetti, E., Maurino, V., Minero, C., Carlin, V., Pramauro, E., Zerbinati, 0., andTosato, M.E. Photocatalytic degradation of atrazine and other s-triazine herbicides. Environ. Sci. TechnoL., 24(10) 1559-1565, 1990. 

Duke, W.B. (1964). The decomposition of atrazine and related s-triazine herbicides by soil microorganisms. M.S. Thesis, Oregon State University, Corvallis, Oregon. 98 pp. 

Bacci, E., A. Renzoni, C. Gaggi, D. Calamari, A. Franchi, M. Vighi, and A. Seven (1989). Models, field studies, laboratory experiments An integrated approach to evaluate the environmental fate of atrazine (s-triazine herbicide). Agric. Ecosys. Environ., 27 513-522. Baker, J.L. and J.M. Laflen (1979). Runoff losses of surface-applied herbicides as affected by wheel tracks and incorporation../. Environ. Qual., 8 602-607. 

Buser, H.R. (1990). Atrazine and other s-triazine herbicides in lakes and in rain in Switzerland. Environ. Sci. Technol., 24 1049-1058. 

Pesticides N-nitrosated under 1m vitro and vivo conditions in the laboratory have included the fungicide ziram (zinc dimethyldithiocarbamate), the insecticides carbaryl (1-naphthyl methyl carbamate) and propoxur (o-isopropoxy phenyl methyl carbamate) and the herbicides benzthiazuron [N-(2-benzothiazolyl)-N -methylurea], simazine [2-chloro-4,6-bis(ethylamino)-s-triazine] and atrazine [2-chloro-4-(ethylamino)-6-(isopropylamino)-s-triazine). 

Kawahigashi H, Hirose S, Ohkawa H, Ohkawa Y (2005) Transgenic rice plants expressing human CYPlAl remediate the triazine herbicides atrazine and simazine. J Agric Food Chem 53 8557-8564... 

More controversially, endocrine disruption as a consequence of exposure to the herbicide atrazine (2-chloro-4-ethylamine-6-isopropylamine-s-triazine), one of the most widely used herbicides in the world, has also been hypothesized to explain various adverse biological effects in frog populations in the United States. Exposure to atrazine in the laboratory at high concentrations, far exceeding those found in the natural environment, has been reported to induce external deformities in the anuran species Rana pipiens, Rana sylvatica, and Bufo americanus (Allran and Karasov 2001). Studies by Hayes et al. have suggested that atrazine can induce hermaphroditism in amphibians at environmentally relevant concentrations (Hayes et al. 2002 Hayes et al. 2003). Laboratory studies with atrazine also indicated the herbicide... 

Gunkel, G. 1981. Bioaccumulation of a herbicide (atrazine, s-triazine) in the whitefish (Coregonus fera J.) uptake and distribution of the residue in fish. Arch. Hydmbiol. Suppl. 59(2/3) 252-287. 

Gunkel, G. and B. Streit. 1980. Mechanisms of a herbicide (atrazine, s-triazine) in a freshwater mollusc (Ancylus fluviatilis Mull.) and a fish (Coregonus fera Jurine). Water Res. 14 1573-1584. 

ATRAZINE 2-Chloro-4-ethyl-amfno-6-isopropylamino-s-triazine, Aatrex Herbicide NL 2 0 1 ... 

Members of an extensive group of sym-triazine herbicides, usually having one or two secondary amine substituents, block the Hill reaction and inhibit photosynthesis in a manner quite similar to that of the urea herbicides. The most widely used, 2-chloro-4-(ethylamino)-6-(isopropylamino)-s-triazine (atrazine), (10), is one of several hundred herbicidal analogs... 

Since many herbicides are crop-specific, herbicide concentrations in farmer s fields are routinely monitored to determine herbicide carry-over. Residual herbicides from the previous year adversely affect alternate crops grown to be grown during the subsequent season. There has been a limited amount of literature describing the successful SFE of herbicides such as sulfonylureas, diruron, linuron, and s-triazines spiked on various solid matrices with COj and methanol modified C02 (1,8-11). Summarized here are the differences in recovery of atrazine from an actual farmer s soil sample as a function of extraction temperature and pressure using both CO2 and methanol modified COj. Also shown are comparisons of recoveries from real vs. spiked samples and also static vs. dynamic modifier addition techniques. 

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