2,4,5, -T 2,4,5-trichlorophenoxyacetic

D, but more ftequently after exposure to another phenoxyherbicide, 2,4,5-T (2,4,5-trichlorophenoxyacetic acid) or its contaminants including 2,3,7,8-TCDD (2,3,7,... 

The photocatalytic degradation of widely used herbicides such as 2,4-D (2,4-dichlorophenoxyecetic acid), 2,4,5-T (2,4,5-trichlorophenoxyacetic acid), bentazon (3-isopropyl-1 H-2,l,3-benzothiadiazin-4(3H)-one 2,2-dioxide), S-tiazines, carbetamide ((R)-l-(ethylcarbamoyl)ethyl carbanilate), and monouron (3-(4-chlorophenyl)-l-methoxy-l-methylurea) in water have been... 

Furthermore, the use of Ralstonia eutropha JMP134-containing sensors for the determination of the herbicide 2,4-dichlorophenoxyacetic acid (2,4-D) has been described [118,121]. This sensor was sensitive to 2,4-D and 2,4,5-T (2,4,5-trichlorophenoxyacetic acid) with a detection Emit of 40 mg 1 with a response time of 15 s. Moreover, catechol, benzoic acid, and sahcylaldehyde caused higher signals, but no or very little signal was obtained for phenol, biphenyl, and the usual substrates such as glucose, fructose, ethanol, and acetate. 

T (2,4,5-trichlorophenoxyacetic acid) ester formulation to a complex mixture of successively less-chlorinated phenoxyacetic esters, and Que Hee, et al. (16) reported a similar dechlorination of 2,4-D (2,4-dichlorophenoxyacetic acid). The toxic 2,4,5-T impurity, TCDD (2,3,7,8-tetrachlorodibenzo-p-dioxin), was dechlo-rinated in a herbicide ester deposit on a sunlit leaf surface within a few hours (Figure 5) (17). 

Perhaps the most renowned example is the extensively-used 2,4,5-T (2,4,5-trichlorophenoxyacetic acid), or rather the 2,3,7,8-tetrachlorodibenzo- -dioxin (TCDD) impurity which sometimes accompanies it. During massive use of the herbicide as a defoliant in the Vietnam war, TCDD was found almost by accident to be one of the most toxic synthetic substances ever tested. Soon, it was shown to be present in domestic 2,4,5-T as well as in the chemical warfare agents. Tests in laboratory animals demonstrated that some of the observed levels indeed were quite high enough to cause toxic effects (32). 

Fig. 19.10 TOC removal with electrolysis time for the degradation of 100 cm3 of 266 mg dm 3 2,4,5-T (2,4,5-trichlorophenoxyacetic add) solutions in 0.05 M Na2S04 + H2SO4 of pH 3.0 at 35°C. (Open circle) Anodic oxidation in a Pt/graphite cell at 100 mA. (Open square) Anodic oxidation with electrogenerated H202 in a Pt/02 cell at 100 mA. (Open triangle) Electro-Fenton with 1 mM Fe2+ in a Pt/02 cell at 100 mA. Photoelectro-Fenton with 1 mM Fe2+ and UVA irradiation in a Pt/02 cell at (open diamond) 100, (filled circle) 300, and (filled square) 450 mA (Boye et al. 2003c)...

T (2,4,5-trichlorophenoxyacetic acid) Amine 2,4,5-T for rice, Dacamine, Ded-Weed, Farmco Fence Rider, Forron, Inverton 245, Line Rider, Super D Weedone, T-Nox, Trinoxol, U 46, Weedar, Weedone... 

T - 2,4,5-trichlorophenoxyacetic acid DDA - bis(4-chlorophenyl)-acetio acid PAA - phenylacetlc acid HP - hepatopancreas ... 

T (2,4,5-trichlorophenoxyacetic acid). In 1970, studies were published which indicated that 2,4,5-T was a teratogen (a substance which causes defects of fetal development)( ). Subsequent studies revealed that the teratogenic effects resulted from a toxic contaminant which was inadvertently formed in the production of... 

ACC 1 -amino-cyclopropane- 1-carboxylic acid 2,4,5-T 2,4,5-trichlorophenoxyacetic acid... 

MCPB, 4-(4-chloro-2-methylphenoxy)butyric acid 2,4,5-T, 2,4,5-trichlorophenoxyacetic acid DDA, bis(j7-chlorophenyl)acetic acid DDT, l,l,l-trichloro-2,2-bis(p-chlorophenyl)ethane 2,4-D, 2,4-dichloro-phenoxyacetic acid PCP, pentachlorophenol. NA, not available. 

T 2,4,5-trichlorophenoxyacetic acid (2,4,5-trichlorophenoxyethanoic acid) a synthetic auxin formeriy wideiy used as a herbicide and defoUant. it is now banned in many countries as it tends to become contaminated with the toxic chemicai dioxin. 

Devine et al. [188] adjust the water sample (IL) to pH2 with hydrochloric add and extract it with benzene (100, M and 50mL). The extract is dried over sodium sulphate, concentrated to O.lmL and methylated by the addition of diazomethane in ethyl ether (ImL). After lOmin, the volume is reduced to about O.lmL, acetone is added and an aliquot is analysed by gas chromatography on one of three columns (1) 5% SE-30 on 60-W mesh Chromosorb W at 175°C, (2) 2% QF-1 on 90-100 mesh Anakron ABS at 175°C or (3) 20% Carbowax 20m on 60-80 mesh Chromosorb W at 220 C. In each instance nitrogen is the carrier gas and detection is by electron capture. The minimum detectable amount of pesticide in water was 2 parts per 10 for MCPA (4-chloro-2-methyl-phenoxyacetic add) and 0.01-0.05 parts per 10 for 2,4-D (2,4-dichloro- henoxyacetic add) and its esters, 2,4,5-T (2,4,5-trichlorophenoxyacetic add), Dicamba, Trifluralin (2-methoxy-3,6-dichlorobeim>ic add), and Fenoprop. Recoveries were 50-60% for MCPA and Dicamba and 80-95% for the other compounds. 

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