Pesticides Simazine

Pesticide Simazine Propazine Atrazine Prometon Ametryn Prometryn... 

SPME coupled to ESI-LC-MS was used to determine the triazine pesticides simazine, atrazine, propazine and prometryn in leachates obtained from soil samples. SPME compared with other extraction methods showed less interference from the matrix compound [513]. 

Ceramic membranes impregnated with crosslinked silylated CD polymers, i.e. organic-inorganic filters were investigated for removal of some organic pollutants from water [59]. It was established that they remove polycyclic aromatic hydrocarbons PAH, the monocyclic aromatic hydrocarbons, trihalo methanes, methyl-f-butyl ether and pesticides. Trihalomethanes are disinfection by-products, they (especially dibromochloromethane) increase the risk of cancer. The pesticides simazine and atrazine are drinking water pollutants. 

Atrazine and simazine arose principally as a result of their use in amenity situations but, since their ban for non-agriciiltiiral purposes, concentrations are generally declining. Fiowever, atrazine and simazine still have some agricultural uses (atrazine on maize and simazine on a wide range of crops), so the risk of pollution still exists when these pesticides are applied in either groundwater or surface water drinking water supply catchments. 

Until recently, the NRA has not participated during the approval process in assessing the potential environmental impact of pesticides. However, the NRA does supply monitoring data to MAFF and HSE for pesticide reviews. These occur once a pesticide has been approved for use for a certain length of time, or when further information is needed on an approved pesticide. In supplying these data, the NRA comments on any areas of concern. This contributed to the 1993 ban on the use of atrazine and simazine on non-cropped land. In January 1995 the NRA s National Centre for Toxic and Persistent Substances (TAPS) was made advisor to the DoF, on the potential impact on the aquatic environment of... 

Figure 13.15 Chromatograms obtained by on-line ti ace enrichment of 50 ml of Ebro river water with and without the addition of different volumes of 10% Na2S03 solution for every 100 ml of sample (a) blank with the addition of 1000 p.1 of sulfite (b) spiked with 4 p.g 1 of the analytes and 1000 p.1 of sulfite (c) spiked with 4 p.g 1 of the analytes and 500 p.1 of sulfite (d) spiked with 4 p.g 1 of the analytes without sulfite. Peak identification is as follows 1, oxamyl 2, methomyl 3, phenol 4, 4-niti ophenol 5, 2,4-dinitrophenol 6, 2-chlorophenol 7, bentazone 8, simazine 9, MCPA 10, atrazine. Reprinted from Journal of Chromatography, A 803, N. Masque et ai, New chemically modified polymeric resin for solid-phase extraction of pesticides and phenolic compounds from water , pp. 147-155, copyright 1998, with permission from Elsevier Science.

Figure 13.19 Chromatograms obtained by on-line SPE-GC-MS(SIM) of (a) 10 ml of tap water spiked with pesticides at levels of 0.1 ng 1 (b) 10 ml of a sample of unspiked tap water. Peak identification foi (a) is as follows 1, molinate 2, a-HCH 3, dimethoate 4, simazine 5, ati azine 6, y-HCH 7, S-HCH 8, heptachloi 9, ametiyn 10, prometiyn 11, fen-itrothion 12, aldrin 13, malatliion 14, endo-heptachlor 15, a-endosulfan 16, teti achlor-vinphos 17, dieldrin. Reprinted from Journal of Chromatography, A 818, E. Pocumll et al., On-line coupling of solid-phase exti action to gas cliromatography with mass specti ometiic detection to determine pesticides in water , pp. 85-93, copyright 1998, with permission from Elsevier Science.

Figure 5.2 Electrospray-MS-MS signal response of seven of the pesticides versus eluent flow rate, based on (a) peak area, and (b) peak height , atrazine , simazine , diuron x, isoproturon , chlorfenvinphos , chlorpyrifos O, alachlor. Reprinted from 7. Chromatogr., A, 937, Asperger, A., Efer, J., Koal, T. and Engewald, W., On the signal response of various pesticides in electrospray and atmospheric pressure chemical ionization depending on the flow rate of eluent applied in liquid chromatography-mass spectrometry , 65-72, Copyright (2001), with permission from Elsevier Science.

The effects of water temperature and pesticide concentration on pesticide recoveries were tested by Moye et al The pesticides included alachlor, atrazine, bromacil, chlorothalonil, chloropyrifos, diazinon, endosulfan, simazine and trifluralin. Temperatures of 5,25,45 and 65 °C were tested and concentrations of 0.1,1.0 and 10 pgL were used. Water temperature had a pronounced effect on the recoveries whereas the concentration did not seem to have as great an effect. 

Kicuchi and Saito used carbon Empore disks in combination with SDB-XD Em-pore disks to extract polar (methamidophos, acephate and trichlorfon) and nonpolar pesticides (diazinon, chloroneb and simazine) from water. The water sample (500 mL) was passed through the disk and the disk simultaneously eluted with 30 mL of acetone-ethyl acetate (1 1). The samples were concentrated and analyzed by GLC/MS. 

Pesticides contaminate not only surface water, but also ground water and aquifers. By 1990 in the USSR, 15% of all pesticides used were detected in underground water [29]. Pesticides were detected in 86% of samples of underground water in Ukraine in 1986-87 (including DDT and its metabolites, HCH, dimethoate, phosalone, methyl parathion, malathion, trichlorfon, simazin, atrazine, and prometrin). In actual fact, the number of pesticides was apparently larger, but the laboratory was able to determine the content of only 30 of the 200 pesticides used at that time in Ukraine [29]. In the 1960s, in the Tashkent and Andizhan oblasts of Uzbekistan, the methylmercaptophos content in the water of studied well shafts was, by clearly underestimated data, 0.03 mg/l (MPC was 0.01 mg/l), of DDT was 0.6 mg/l (MPC was 0.1 mg/ I), and of HCH was 0.41 mg/l (MPC was 0.02 mg/l) [A49]. 

In several AT studies, pesticide levels in the Ebro were found to be high. Hildebrandt et al. [50] found a homogeneous contamination pattern from atrazine (and also from simazine from May 2000) in intensive Rioja cultivation areas throughout the Ebro. Nearer to the delta, Barata et al. [72] found high levels of bentazone, methyl-4-chlorophenoxyacetic acid, propanil, molinate and fenitrothion in water, while Kuster et al. [71] found low concentration levels of atrazine and simazine at the delta, but high levels of other pesticides used in rice cultivation. Importantly, Hildebrandt et al. [50] found that levels of pesticides in groundwater... 

Kavetskii et al. [224] developed a method for the simultaneous determination of pesticides in soil. A combination of thin layer chromatography and gas chromatography was used. The pesticides examined were 4,4 DDT, 4,4 DDD, 4,4 DDE, 2,4 DDT, GHCG, aGHCG, Metaphos, Phosphamidon, Phozalone, Atrazine, Prometryne, Simazine and 2,4 dichlorophenoxy acetic acid. Detection limits were in the range 0.5-5pg kgy1. 

Groundwater contamination by agrochemicals from non-point sources has been well documented in a number of countries [26-28, 30-32], The pesticides that have been detected in regional council groundwater surveys include 2,4-D, Amitrole, Picloram, Simazine and Atrazine [20]. 

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