Carbon-14 atrazine

Miller, J.L., A.G. Wollum, and J.B. Weber (1997). Degradation of carbon-14-atrazine and carbon-14-metolachlor in soil from four depths. J. Environ. Qual., 26 633-638. 

Goerge, G. and R. Nagel. Kinetics and metabolism of carbon-14 lindane and carbon-14 atrazine in early life stages of zebrafish (Brachydanio rerio). Chemosphere 21 1125-1137, 1990. 

Profile designation Depth from soil surface Organic carbon Atrazine Alachlor... 

Triazines pose rather more of a problem, probably because the carbons are in an effectively oxidized state so that no metaboHc energy is obtained by their metaboHsm. Very few pure cultures of microorganisms are able to degrade triazines such as Atrazine, although some Pseudomonads are able to use the compound as sole source of nitrogen in the presence of citrate or other simple carbon substrates. The initial reactions seem to be the removal of the ethyl or isopropyl substituents on the ring (41), followed by complete mineralization of the triazine ring. 

Torrents A, BG Anderson, S Bilboulian, WE Johnson, CJ Hapeman (1997) Atrazine photolysis mechanistic investigations of direct and nitrate-mediated hydroxyl radical processes and the influence of dissolved organic carbon from the Chesapeake Bay. Environ Sci Technol 31 1476-1482. 

A number of substituted triazines are used as herbicides, and their biodegradation has been discussed in Chapter 10, Part 1. Treatment of soil contaminated with atrazine (2-chloro-4-(ethylamino)-6-isopropylamino-l,3,5-triazine) illustrated a number of significant features. Although the soil that was used had the potential for degradation, a laboratory experiment with Pseudomonas sp. strain ADP that had an established potential for atrazine degradation revealed important limitations. There was a substantial decline in the numbers of Pseudomonas sp. strain ADP and only limited mineralization. Supplementation with citrate or succinate increased the survival of the strain, and successful mineralization was dependent on the preservation of a carbon/nitrogen ratio >10 (Silva et al. 2004). The last would apply generally to substrates with a low C/N ratio such as triazines. 

Atrazine enters plants primarily by way of the roots and secondarily by way of the foliage, passively translocated in the xylem with the transpiration stream, and accumulates in the apical meristems and leaves (Hull 1967 Forney 1980 Reed 1982 Wolf and Jackson 1982). The main phytotoxic effect is the inhibition of photosynthesis by blocking the electron transport during Hill reaction of photosystem II. This blockage leads to inhibitory effects on the synthesis of carbohydrate, a reduction in the carbon pool, and a buildup of carbon dioxide within the leaf, which subsequently causes closure of the stomates, thus inhibiting transpiration (Stevenson et al. 1982 Jachetta et al. 1986 Shabana 1987). 

Hamilton, P.B., G.S. Jackson, N.K. Kaushik, and K.R. Solomon. 1987. The impact of atrazine on lake periphyton communities, including carbon uptake dynamics using track autoradiography. Environ. Pollut. 46 83-103. 

Hapeman, C J., S. Bilboulian, B.G. Anderson, and A. Torrents. 1998. Structural influences of low-molecular weight dissolved organic carbon mimics on the photolytic fate of atrazine. Environ. Toxicol. Chem. 17 975-981. 

Quantification is usually achieved by a standard addition method, use of labeled internal standards, and/or external calibration curves. In order to allow for matrix interferences the most reliable method for a correct quantitation of the analytes is the isotope dilution method, which takes into account intrinsic matrix responses, using a deuterated internal standard or carbon-13-labeled internal standard with the same chemistry as the pesticide being analyzed (i.e., d-5 atrazine for atrazine analysis). Quality analytical parameters are usually achieved by participation in interlaboratory exercises and/or the analysis of certified reference materials [21]. 

Steinheimer et al. [103] used supercritical fluid chromatography to extract Atrazine, diethyl Atrazine and Cyanazine from Canadian cornbelt soils by supercritical fluid extraction with carbon dioxide. 

Methyl ferf-butvl ether. Thiram Carbon monoxide, see Acetaldehyde. Atrazine. Bromacil. Dalapon-sodium. Dieldrin, 1.4-Dioxane, Diuron, Formaldehyde, Formic acid, Malathion, Maleic anhydride. Methanol, Methyl chloride. Methylene chloride. Methyl iodide, 2-Methylpropene, fV-Nitrosodimethylamine, Oxalic acid, Phorate, Picloram, 2,4,5-T, TCDD, Tolnene, Triflnralin... 

Trichlorobenzene. Trichloroethylene Hydrogen azide, see Alachlor. Aldicarb. Atrazine Hydrogen bromide, see Ethylene dibromide Hydrogen chloride, see Atrazine. Captan. Carbon tetrachloride. Chloroform. Chlorpropham. Chlorpyrifos. 1.2-Dichloroethane. Diuron. Endrin. Formaldehyde. Heptachlor. Heptachlor epoxide. Hexachlorocyclopentadiene. Linuron. Methyl chloride. Methylene chloride. Methyl formate. Monuron. Propanil. Tetrachloroethylene. Trichloroethylene. Vinyl chloride Hydrogen cyanide, see Acetontrile. Alachlor. Aldicarb. 

A facultative anaerobic bacterium isolated from a stream sediment utilized atrazine as a carbon and nutrient source. Microbial growth was observed but no degradation products were isolated. At 30 °C, the half-life was estimated to be 7 d (Jessee et ah, 1983). 

Plant. In tolerant plants, atrazine is readily transformed to hydroxyatrazine which may degrade via dealkylation of the side chains and subsequent hydrolysis of the amino groups with some evolution of carbon dioxide (Castelfranco et al, 1961 Roth and Knuesli, 1961 Humburg et al, 1989). In corn juice, atrazine was converted to hydroxyatrazine (Montgomery and Freed, 1964). In both roots and shoots of young bean plants, atrazine underwent monodealkylation forming 2-chloro-4-amino-6-isopropylamino-s-triazine. This metabolite is less phytotoxic than atrazine (Shimabukuro, 1967). 

Photolytic. Low et al. (1991) reported that the photooxidation of a saturated solution of atrazine by UV light in the presence of titanium dioxide resulted in the formation of ammonium, carbonate, chloride, and nitrate ions. Evgenidou and Fytianos (2002) also studied the photodegradation of atrazine using UV light (X >290 nm) in distilled water (pH 7.1, conductivity 456 mS/cm, dissolved oxygen 8.0 mg/L, total organic carbon 0.8 mg/L), lake water (pH 8.7,... 

Products formed from the combustion of atrazine at 900 °C included carbon monoxide, carbon dioxide, hydrochloric acid, and ammonia (Kennedy et al, 1972, 1972a). At 250 °C, however, atrazine decomposes to yellow flakes which were tentatively identified as primary or secondary amines (Stojanovic et al., 1972). Tirey et al. (1993) evaluated the degradation of atrazine at 12 different temperatures. When atrazine was oxidized at the temperature range of 300-800 °C, numerous reaction products were identified by GC/MS. These include, but are not limited to,... 

Photolytic. Pelizzetti et al. (1990) studied the aqueous photocatalytic degradation of prometon and other s-triazines (ppb level) using simulated sunlight (7, >340 nm) and titanium dioxide as a photocatalyst. Prometon rapidly degraded forming cyanuric acid, nitrates, the intermediate tentatively identified as 2,4-diamino-6-hydroxy-7V,A -bis(l-methylethyl)-s-triazine, and other intermediate compounds similar to those found for atrazine. Mineralization of cyanuric acid to carbon dioxide was not observed. 

Roy, W.R. and Krapac, I.G. Adsorption and desorption of atrazine and deethylatrazine by low organic carbon geologic materials,/. Environ. Qual, 23(3) 549-556, 1994. 

Carbon nanotubes could be also used in a format of disc. A comparison smdy showed that the double-disk system (comprising two stacked disks with 60 mg of CNTs) exhibited extraction capabilities that were comparable to those of a commercial Cig disk with 500 mg sorbent for nonpolar or moderately polar compounds. Moreover, the former system was more powerful than the latter for extracting polar analytes. The triple-layered CNTs disk system showed good extraction efficiency when the sample volume was up to 3,000 mL. Katsumata et al. [136] obtained very high enrichment factor for preconcentration of atrazine and simazine (3,900 and 4,000, respectively, for 200 mL of sample solution when only 30 mg of MWCNTs was used in the format of disk. 

Dwell time, or the time the molecule was actually in the lamp unit, and concentration were two parameters that affected the rate of degradation. Mass spectra of the trimethylsilyl (TMS) derivatives of atrazine subjected to UV-ozonation revealed a number of dehalogenated, dealkylated s -triazines, paraquat yielded the 4-picolinic acid, and 2,4-D gave oxalic acid, glycolic acid and several four-carbon oxidation products. The economics of UV-ozonation as a pretreatment for land disposal compares favorably with incineration and other options open to the small pesticide user. 

A final example in Table X shows the log P computation which CLOGP-3 performs on atrazine. If the three Isolating Carbon atoms in the ring were truly isolating, the negative fragments would predominate and a value of -1.15 would be obtained. The... 

---