Dinitroaniline herbicides water

Dinitroaniline herbicides, in general, are very lipophilic, hence they are insoluble in water. They are stable under acidic or alkaline conditions. Dinitroaniline herbicides are potentially dissipated in the environment via photodegration and volatilization. 

Owing to its low water solubility and high octanol/water partition coefficients, dinitroaniline herbicides adsorb and bind to soil macromolecules and show minimal leaching potential. Dinitroanilines herbicides show good soil residue activities with soil half-lives ranging from 30 days for benfluralin and oryzalin to 6-7 months for trifluralin. Al-Dealkylation (aerobic conditions) and reduction of the nitro group to an amino moiety (anaerobic conditions) have been reported as major soil degradation pathways. 

Residual pendimethalin in various crops was determined as follows." A 10-20-g amount of fruits or vegetables was extracted by blending twice with 200 mL of methanol. Grasses and mint were extracted with 200 mL of methanol-water (1 1, v/v). Nuts were extracted with 200 mL of n-hexane-2-propanol (3 1, v/v). For the residue analysis of the dinitroaniline herbicides butralin, dinitramine, ethalfluralin, pendimethalin, and trifluralin, a tomato sample (5 g) was extracted twice with 20 mL of methanol in a Sorvall homogenizer and filtered through filter paper. Benfluralin and trifluralin residues in the sample (10 g) were extracted with 100 mL of acetonitrile-water (99 1, v/v) in 250-mL screw-cap jars with Teflon liners rotated for 1 h on an end-over-end shaker (40 rpm). ... 

Dinitroaniline herbicides have low soil mobility potential. Herbicide residues in the treated field are usually incorporated into the upper layers of the soil mainly as unextractable bound residue therefore, the movement of dinitroaniline herbicides from soil to the water compartment is minimal. Run-off is the principal route, which could lead to the contamination of surface waters. Residue methods were developed to measure the parent concentration in water samples. 

Cabras et al reported an HPLC residue method for dinitroaniline herbicides. A water sample was analyzed after purification and concentration on a Bond-Elut Ci8 cartridge (500-mg/2.8-mL). The cartridge was treated with 10 mL of methanol... 

The primary purpose of this project was to demonstrate that aquatic model ecosystems could be further scaled up in size to provide greater amounts of the components (biomass, soil and water) to satisfactorily study metabolism kinetics. We used trifluralin, a dinitroaniline herbicide, since its metabolic pathways are well known and the metabolites were readily available. 

This spring Elanco Products Company (a Division of Eli Lilly and Company) introduced a 60 /o dry flowable (or water dispersible granule) formulation of BALAN. BALAN is a preemergence, dinitroaniline herbicide used on peanuts and lettuce. BALAN Dry Flowable is an addition to formulations of BALAN which are produced and sold by Elanco. BALAN LC, a 1.5 Ib/gal emulsifiable concentrate which has been on the market for several years, is often tank mixed with several other agrichemicals. Therefore, it was critical to evaluate this new product form for tank mix performance with all agrichemicals with which it could be tank mixed. 

The dinitroaniline herbicides are relatively insoluble in water (and consequently probably in the cytoplasm) so that a mechanisnrof resistance based upon hyperstability would probably allow for a rather complete resistance to these compounds. Other compounds, like colchicine, are much more water-soluble and, at the high concentrations of these compounds required to elicit effects in all plants... 

The main field of application of dinitroaniline herbicides is the control of annual grass weeds. Some annual dicotyledonous weeds are also sensitive to dinitroaniline herbicides in the initial growth stage. All members of the group are fairly volatile, and are hence sprayed before sowing to the soil surface and immediately incorporated to a soil depth of 6-8 cm. Owing to their poor water solubility, they are not absorbed from dry soil in adequate quantity by the plant, so under dry conditions their action is unsatisfactory. 

The determination of volatile nitrosamines in crops and soils treated with dinitroaniline herbicides was reported by West and Day (47). Measurement was accomplished by means of a gas chromatograph-thermal energy analyzer. The sensitivity of the methods was 0.2, 0.05 and 0.01 ppb for dipropylnitrosamine in crops, soil and water respectively. 

Figure 4. Photodecomposition of dinitroaniline herbicides in water I isopropalin (A), fluchloralln ( ) and profluralin (0).

Dinitroaniline herbicides (dinitramine, ethalfluralin, trifluralin, pendimetl alin, isopropalin) were extracted from soil and water matrices and baseline resolved on... 

Guan, F. et al. Headspace solid-phase microextraction and gas chromatographic determination of dinitroaniline herbicides in human blood, urine and environmental water, /. Chromatogr. B, 714, 205, 1998. 

Substituted dinitroanilines (Fig. 10, Table 3) are an important series of selective herbicides commercially introduced in agriculture in the 1960s. Trifluralin is the most prominent member of this series. Nitralin and Benfluralin have also received widespread usage, while Profluralin is a relatively recent herbicide of this class. Dinitro anilines show very low water solubilities. Nitralin and Benfluralin have low vapor pressures and are nonvolatile, while Trifluralin is relatively volatile. All these compounds have been shown to be relatively immobile in soil systems. 

N-sec-butyl-4-tert-butyl-2,6-dinitroaniline org chem C14H21N3O4 Orange crystals with a melting point of 60-6rC solubility in water is 1.0 part per million at 24°C used as a preemergence herbicide. en sek bytid al for tart byud al tu siks, dT,nT-tro an-a,len ... 

Studies were initiated at Iowa State University in 1977 to determine if pesticides would be contained and degraded when deposited in water/soil systems. Although the addition of known amounts of the selected pesticides was controlled, the physical environment was not temperature, humidity, wind speed, etc. were normal for the climate of Central Iowa. Four herbicides and two insecticides were chosen on the basis of three factors. Firstly, they represented six different families of pesticides. The four herbicides, alachlor, atrazine, trifluralin, and 2,4-D ester, represent the acetanilides, triazines, dinitroanilines, and phenoxy acid herbicides, respectively. The two insecticides, carbaryl and para-thion, represent the carbamate and organophosphorus insecticides, respectively. Secondly, the pesticides were chosen on the basis of current and projected use in Iowa Q) and the Midwest. Thirdly, the chosen pesticides were ones for which analytical methodology was available. 

---