Herbicides triazine type

In many applications nowadays it is essential to link a mass spectrometer to the gas chromatography in order to achieve positive identification and sensitivity of analysis. Some 12 types of compounds are listed in Table 1.11(a) which are based on the application of this technique, viz. polyaromatic hydrocarbons, polychlorobenphenyls, dioxins, chloro, carbamate and triazine types of herbicides and pesticides, Diazinon, Dicamba, Imidazoline and Cyperquat herbicides and herbicide pesticide mixtures. 

Triazine type herbicides Methanol enrichment on Cis cartridge Gradient Ci8 high-performance liquid chromatography [72]... 

The principle methods used for the determination of triazine-type herbicides are gas chromatography (Table 4.6) and high-performance liquid chromatography (Table 4.7). Other methods that have been used include isota-choelectrophoresis [369], ELISA [370-375], spectrophotometry [376,377] and thin-layer chromatography [378] (Table 4.8). 

Table 4.6. Gas chromatographic methods for the determination of triazine-type herbicides in soil extracts (from author s own files)...

In the course of their research work on nonpersistent herbicides of the triazine type, Matolcsy and coworkers (Szatala et al., 1972 Matolcsy, 1973) utilised the known elimination reaction of Mannich bases (3-oxoamines), which involves the formation of amine and unsaturated ketone. This specific reactivity of 3-oxoamines is caused by the -/and —M effects of the carbonyloxygen. Due to the partial positive charge of the carbonyl carbon atom, the adjacent carbon atom acquires an acid character, and with the participition of the nitrogen atom a zwitterion is formed, which furthers the amine elimination ... 

Relationships between the chemical structure and the effect of herbicides of the. s-triazine type have been studied by several workers in addition to Gysin and Knusli, whose work has already been cited (1960). McWhorter and Holstun... 

The cause of the selectivity of herbicides of the triazine type has also been investigated by many authors. Roth (1957) investigated the resistance of maize to simazine, and established that the freshly pressed sap of the maize plant decomposes simazine during 100 hours of incubation, while simazine is not decomposed in the pressed-out sap of wheat, which is sensitive to simazine. However, this detoxifying effect does not occur after heat treatment of the pressed-out sap of the maize plant, indicating that a heat-sensitive substance is responsible for the effect (Roth and Knusli, 1961). The substance that detoxifies simazine has been isolated by Castelfranco er a/. (1961). This product, which is sensitive to heat in the raw state but thermostable after purification, proved to be identical with the... 

Herbicides of the triazine type and their metabolites have a very low toxicity for warm-blooded animals. Acute oral toxicities (ld J measured in rats are simazine 5000 mg/kg, atrazine 3080 mg/kg, propazine 5000 mg/kg, prometone 2980 mg/kg, desmetryne 1390 mg/kg, ametryne 1405 mg/kg, prometryne 3150-3750 mg/kg, terbutryne 2400-2980 mg/kg, methopfotryne 5000 mg/kg, and aziprotryne 5833 mg/kg. 

Due to their difference in chemistry, all PSII-inhibiting herbicides demonstrate different binding properties. For example, urea/triazine type inhibitors were proposed to be oriented towards Set 264, triazinones towards Ala 251 and phenolic herbicides were oriented towards His 215 (Table 1). ... 

During the short time of their application in the early 1980s, DLI interfaces were often applied for substance-specific analysis [60] of various types of pesticides and herbicides (triazines, carbamates, organophosphorus compounds) [61-67], chlorinated phenoxyacetic acids, phenylureas, analides (alachlor, propachlor and aldi-carb) [63]. 

The aliphatic amines are valuable intermediates for chemical synthesis applications, Reaction of ethylamine with cyanuric chloride yields triazine-type herbicides, Diethylamine is used in the preparation of vulcanization accelerators where reaction with carbon disulfide yields a dithiocarbamate. Triethyl-amine is used as an acid acceptor in chemical syntheses and as a salt former in various purification processes. The amine is used as a corrosion inhibitor in aqueous systems, as a catalyst in polyurethane applications, in textile and photographic applications, and in anodic electrocoating. 

Abstract The soil as an adsorbent has various active sites leading to rather complicated adsorption mechanisms with environmental pollutants, like pesticides. According to earlier results the chloroacetani-lide type herbicides as solutes resulted in two-step isotherms on soils and quartz. This phenomenon has not been observed yet concerning trace compounds in the environment. In this case the so-called distributed reactivity model is used, suggesting that the total sorption is given as the sum of the local adsorption isotherms. The adsorption of isoproturon (urea-type herbicide) and prometryn (5-triazine type herbicide) was studied on quartz at different pH values. 

Isoproturon is an urea-type herbicide, while prometryn is a triazine-type herbicide (Fig. 1) and both contain more nitrogen atoms with different basicity. 

Photocatalysed degradation of s-triazine type herbicides with Ti02 has been studied and it was observed that cyanuric acid is the final photoproduct [59-62]. 

Triazine-type herbicides were detected in the lower nanogram range by this photosynthesis inhibition reaction with chloroplasts obtained from parts of oats, spinach, beans, and watercress (170) ... 

In Rps. viridis no site-directed mutants are available. However, a number of herbicide-resistant mutants have been characterized (Sinning et al., 1989 Ewald et al., 1990). Herbicides of the triazine type compete with Qb for the binding pocket and their binding is controlled by nearby residues which also are potential candidates for proton donors to reduced Qb- Recently, we have characterized the kinetics and pH-dependence of the electron transfer in the quinone acceptor complex in Rps. viridis wild type (Wt). To get further insight into the mechanisms of quinone reduction we studied these reactions in herbicide-resistant mutants. In this contribution we present a first glance on these experimental results. 

It has already been mentioned that the degradation of s-triazine herbicides such as atrazinc in soil can be described by two reaction types only, hydrolysis and reductive dealkylation (see Figure 10.3-8). Application oF these two reaction types to a specific s-triazinc compound such as atrazinc provides the reaction network shown in Figure 10,3-12. This can also be vcriFicd by running this example on h ttp //www2,chemie,uni-erlangen.de/semces/eros/,... 

The principle was demonstrated using triazine herbicides as templates and by varying the type of functional monomer and the monomer composition. With a final batch size of ca. 40 mg of monomer, the consumption of monomers and template is significantly reduced and the synthesis and evaluation can take place in standard high-performance liquid chromatography (UPLC) autosample vials. After synthesis. 

Aliphatic hydrocarbons, triazine, substituted urea type and phenoxyacetic acid types of herbicides, Fluazifop and Fluazifop-butyl herbicides, ethylene diamine tetracetic acid salts in soil, aliphatic and polyaromatic hydrocarbons, phthalate esters, various organosulphur compounds, triazine herbicides, optical whiteners, mixtures of organic compounds and organotin compounds in non-saline sediments, aromatic hydrocarbons, humic and fulvic acids and mixtures of organic compounds in saline sediments and non-ionic surfactants and cobalamin in sludges. 

This technique has been used to determine the following types of organic compounds in soil polychlorobiphenyls, chlorinated insecticides, triazine herbicides, paraquat and diquat. 

Cotterill [100] studied the effect of ammonium nitrate fertilizer on the electron capture or nitrogen specific gas chromatographic determination of Triazine plus other types of herbicide (Atrazine(2-chloro-4-ethylamino-6-isopropylamino, 1,3,5 triazine), Simazine (2-chloro-4.6 bis ethyl amino 1,3,5 triazine), Linuron (3,4,-chlorophenyl-l-methoxy-l-methyl urea), Metribuzin, Triallate and Phorate) residues in soil. 

Herbicides are used widely throughout the world to control weeds and exist in a wide variety of different types. Examples of classes of herbicide include the triazine, sulfonylurea, phenoxy, and quaternary ammonium herbicides. 

Liquid chromatography -APCI-MS is applicable to many different types of pesticide structures, such as triazines, phenylurea herbicides, acetanilides, and OPPs. A study of 12 pesticides and pesticide degradation products demonstrated the sensitivity of the technique for OPP determination, with detection limits for water samples of about 0.001-0.005 /zg/L (32). 

Research had confirmed that no parent simazine residues were found in treated com plants, and additional data on the dissipation pathway of simazine needed to be developed. Research also indicated that triazines interfered with the photosynthetic process on susceptible growing weeds, as evidenced by the appearance of chlorotic leaves. Steps were undertaken to elucidate simazine s dissipation pathway and herbicidal mode of action. In Basel, Dr. Gast (1958) showed that the accumulation of starch by common coleus (Coleus blumei Benth.) plants was inhibited from treatment with 2-chloro-4,6-bis-(alkyl-amino)-triazines due to the inhibition of sugar synthesis. At the same time, Moreland et al. (1958) found weed control activity could be reduced by supplying carbohydrates to the plants through their leaves and that simazine was a strong inhibitor of the Hill reaction in photosynthesis. Exer (1958) found that triazines inhibited the Hill reaction as strongly as urea of the CMU (monuron) type. 

---