122-34-9 Simazine

IUPAC name 2-chloro-4,6-bis(ethylamine)-l,3,5-triazine Molecular formula C7H12CIN5 Toxicity class USEPA IV WHO III 

Toxicity The acute oral toxicity of simazine for rats is more than 15,380 mg/kg, and the acute dermal LD50 in rabbits is 10,200 mg/kg. It demonstrated moderate primary skin and eye irritation effects in rabbits. The acute inhalation LC50 to rats is greater than 5 mg/L. Reports have indicated that simazine caused no serious effects in humans except minor skin rashes in some cases. Similarly, it caused no long-term effects in humans.5,36 

---

Triazines. Triazine herbicides are one of several herbicide groups that are heterocycHc nitrogen derivatives. Triazine herbicides include the chloro-, methylthio-, and methoxytriazines. They are used for the selective pre-emergence control and early post-emergence control of seedling grass and broadleaved weeds in cropland (299). In addition, some of the triazines, particularly atrazine, prometon [1610-18-0] and simazine [122-34-9] are used for the nonselective control of vegetation in noncropland (2). Simazine may be used for selective control of aquatic weeds (2). 

Herbicides. An array of herbicides are registered for use in aquatic sites, but copper sulfate and diquat dibromide are of additional interest because they also have therapeutic properties (9,10). Copper sulfate has been used to control bacteria, fungi, and certain parasites, including Jchthjophthirius (ich). Diquat dibromide can control columnaris disease, but it also exhibits fungicidal properties (9,10). EPA recentiy proposed to limit the amount of diquat dibromide, endothaH, glyphosate, and simazine that can be present in drinking water therefore, the use of these compounds may be reduced if they cannot be removed from the effluent. 

Herbicides Diquat bromide Atrazine Simazine Diiiron... 

Figure 3 Loads of simazine, trifluralin, and j -HCH (tonnes/year) entering the North Sea from England and Wales during 1990-94...

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. 

Proposed by Water Research Centre, s Proposed by NRA. llAtrazinie and Simazine. 

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... 

Where both atrazine and simazine are released, the figure in aggregate is 350 grams. 

Simazine 0.004 0.004 Problems with blood Herbicide runoff... 

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.

Depending on the duration of heating yellow-green to dark green chromatogram zones were produced on a weakly colored background. The detection limits of the triazine herbicides cyanazine (h/Jf 25-30), simazine (h/Jf 30-35), atrazine (h/Jf 40-45), terbutylazine (h/Jf 45-50) and anilazine (h/Jf 60-65) were 20 ng substance per chromatogram zone. 

Fig. 1 Reflectance scan of a chromatogram track with 100 ng each of 1 = cyanazine, 2 = simazine, 3 = atrazine, 4 = terbutylazine, 5 = anilazine per chromatogram zone.

The substances methoprotryn (hRf 30-35), desmetryn (h/ f 40-45), ametryn (hRf 55-60), prometryn (h/Jf 65-70) and dipropretryn (h/ f 70-75) separated using mobile phase 1 and the components cyanazine (hRf 20-25), simazine (tiRf 30-35), atrazine (hRf 35-40), terbutylazine (h/Jj 45-50) and anilazine (h/ f 60-65) chromatographed with mobile phase 2 all yielded intense grey to brown-colored zones on a light brown background, that appear intense purple-red when viewed from the back of the plate (Wurster s red). 

---