Atrazine values

ELP fusion protein (Fig. 9, center). It was shown that picomolar levels of ELP fusion proteins could be purified via ELP coaggregation [47, 48]. The value of this technique was shown by the purification of low levels of ELP fused to an anti-atrazine antibody [49]. 

Pesticide storehouses were examined in five regions of the Astrakhan Oblast because of the rise in the Caspian sea level and the possibility of flooding in 1993-95. Only eight of 39 storehouses were standard however, even they did not meet construction standards, and most were in terrible condition. Residual pesticides contaminated the land surrounding many of these storehouses. In the Volodarsk Region, the maximal values for contamination were atrazine at 1330 times MPC DDT at 53 times MPC, methyl parathion at 1330 times MPC, trifluraline at 8000 times MPC, and phosalone at 107 times MPC. 

From Figure 9 it can be concluded that the sensitivity of the assay is adequate to screen water samples for the presence of atrazine at a MAC value of 0.1 ppb. In a preliminary experiment 10 river water samples were screened for the presence of atrazine. In eight out of 10 an immunological response corresponding to atrazine levels greater than 0.1 ppb could be confirmed by GC-MS analysis. The other two samples contained atrazine at levels below 0.1 ppb (both with the enzyme immunoassay as with the GC-MS analysis). 

Wauchope and Myers [116] studied the adsorption-dispersion kinetics of Atrazine and Linuron in sediment-aqueous slurries. The resulting adsorption or desorption was very rapid, approaching 75% of equilibrium values within 3-6min. Chlorinated adsorption of the herbicide on the sediment was completely reversible after 2h of adsorption. 

Li and Felbeck (1972) reported that the half-lives for atrazine at 25 °C and pH 4 with and without fulvic acid (2%) were 1.73 and 244 d, respectively. The hydrolysis half-lives in a 5 mg/L fulvic acid solution and 25 °C at pH values of 2.9, 4.5, 6.0, and 7.0 were 34.8, 174, 398, and 742 d, respectively. The only product identified was 2-(ethylamino)-4-hydroxy-6-isopropylamino-5-triazine (Khan, 1978). The primary degradative pathway appears to be chemical (i.e., hydrolysis) rather than microbial (Armstrong et al., 1967 Best and Weber, 1974 Gormley and Spalding, 1979 Geller, 1980 Lowder and Weber, 1982 Skipper et al, 1967). 

Chemical/Physical. The hydrolysis half-lives of atrazine in aqueous buffered solutions at 25 °C and pH values of 1, 2, 3, 4, 11, 12 and 13 were reported to be 3.3, 14, 58, 240, 100, 12.5, and 1.5 d, respectively (Armstrong et al., 1967). Atrazine does not hydrolyze in uncatalyzed solutions, even under elevated temperatures. The estimated half-life of atrazine in neutral, uncatalyzed water at pH 6.97 and 25 °C is 1,800 yr. Under acidic conditions, hydrolysis proceeds via mono- and diprotonated forms (Plust et al., 1981). Atrazine is stable in slightly acidic or basic media, but is hydrolyzed to hydroxy derivatives by alkalies and strong mineral acids (Windholz et al., 1983). Atrazine reacts with strong mineral acids forming hydroxyatrazine (Montgomery and Freed, 1964). 

Forget, J., Pavilion, J.F., Menasria, M.R., and Bocquene, G. Motality and LC50 values for several stages of the marine copepod Tigriopus brevicornis (Muller) exposed to the metals arsenic and cadmium and the pesticides atrazine, carbofuran, dichlorvos, and malathion, Ecotoxlcol. Environ. Saf., 40(3) 239-244, 1998. 

Atrazlne. Atrazine is a chlorinated, a-triazine herhicide. Its water solubility is 33 npm (18), its vapor pressure is 3 X 10 torr (19), and H < 10 atm-i /mole. The pK of atrazlne is 1.68 (40). Kqp values of 51 and 214 have been reported (19,20) and the mean of 56 soils was reported to be 163+80 (41). The Kjj of atrazlne varies between 1 and 8 in certain soils, and seems to be dependent on the cations present (42). Kj values of 0.40-0.46 were also recently reported for aquifer sands in Nebraska (43). Atrazlne is in Helling s mobility class 3, which is the intermediate mobility class (10). (Class 5 is the most mobile, and class 1 is immobile.)... 

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... 

The 2003 ACGIH threshold limit value-time-weighted average (TLV-TWA) for atrazine is 5mg/mh... 

Atrazine is still one of the most widely used herbicides. Estimate the fraction of total atrazine present in truly dissolved form (a) in lake water exhibiting 2 mg POC-L1, (b) in marsh water containing 100 mg solids-L-1, if the solid s organic carbon content is 20%, and (c) in an aquifer exhibiting a porosity of 0.2 by volume, a density of the minerals present of 2.5 kg-L l, and an organic carbon content of 0.5%. Assume that partitioning to POM is the major sorption mechanism. You can find Kioc values for atrazine in Fig. 9.9. Comment on which value(s) you select for your calculations. 

The loss of atrazine due to diffusion into the sediment is estimated from Eq. 24-29. Note that in spite of the fairly small Koc value of atrazine, the chemical sorbs well in the sediments due to the large rsf value ... 

To summarize, in flow regime I the maximum atrazine concentation atx = 10 km is reduced to (0.20/0.63) 100% = 32% of its original value. This reduction is significantly larger than that from any other possible mechanism to reduce the concentration. In contrast, in flow regime II dispersion is not yet felt at x = 10 km. 

To inhibit the indirect reaction, Beltran et al. (1994) found that it is sometimes not sufficient to use a low pH-value, even as low as pH = 2. Comparing the reaction rate of atrazine with ozone at pH = 2 with and without teri-butanol, they observed a decrease in the reaction rate in the presence of TBA. This means that there were radical reactions even at this extremely low pH. 

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