Substituted Urea

2020 ◽  
Author(s):  
Keyword(s):  
Substituted Urea

ChemInform Abstract: Aminomethylation of N,N′- and N,N,N′-Substituted Urea with N-Methylene- tert-butylamine.

ChemInform ◽  
2010 ◽  
Vol 23 (23) ◽  
pp. no-no
Author(s):  
A. L. KOVALENKO ◽  
YU. V. SEROV ◽  
A. A. NIKONOV ◽  
I. V. TSELINSKII
Keyword(s):  
Tert Butylamine ◽  
Substituted Urea

Resistance to Substituted Urea Herbicides inLolium rigidumBiotypes

1997 ◽  
Vol 57 (2) ◽  
pp. 126-136 ◽  
Author(s):  
Rafael De Prado ◽  
Jose L. De Prado ◽  
Julio Menendez
Keyword(s):  
Substituted Urea

Tethered Libraries:  Solid-Phase Synthesis of Substituted Urea-Linked Bicyclic Guanidines

2001 ◽  
Vol 3 (2) ◽  
pp. 189-195 ◽  
Author(s):  
Achyuta N. Acharya ◽  
Adel Nefzi ◽  
John M. Ostresh ◽  
Richard A. Houghten
Keyword(s):  
Solid Phase Synthesis ◽  
Solid Phase ◽  
Phase Synthesis ◽  
Substituted Urea

Multiresidue Method for Determining Substituted Urea Herbicides in Foods by Liquid Chromatography

1987 ◽  
Vol 70 (4) ◽  
pp. 740-745
Author(s):  
Ronald G. Luchtefeld
Keyword(s):  
Liquid Chromatography ◽  
Standard Deviation ◽  
Column Chromatography ◽  
Food Products ◽  
Chemical Derivatization ◽  
Florisil Column ◽  
Average Recovery ◽  
Multiresidue Method ◽  
Florisil Column Chromatography ◽  
Substituted Urea

Abstract A method is described for determining substituted urea herbicides in foods. The residues are extracted from the product with methanol, and the food coextractives are removed by using solvent partitioning and Florisil column chromatography. The extract is analyzed using liquid chromatography with postcolumn photodegradation, chemical derivatization with orthophthalaldehyde, and spectrofluorometry. Recoveries were determined by spiking 8 different food products with 6 phenylureas—chlorbromuron, chloroxuron, diuron, fluometuron, linuron, and metobromuron—at 0.05 and 0.5 ppm. Three determinations were made at each level for each product. Average recovery at 0.05 ppm was 95% (with a standard deviation of 7.9%), and at 0.5 ppm, 98% (with a standard deviation of 6.9%).

Effect of Surfactants on Leaching of Substituted Urea Herbicides in Soil

Weeds ◽  
1967 ◽  
Vol 15 (3) ◽  
pp. 249 ◽  
Author(s):  
D. E. Bayer
Keyword(s):  
Substituted Urea

Microbial Degradation of Five Substituted Urea Herbicides

Weed Science ◽  
1969 ◽  
Vol 17 (1) ◽  
pp. 52-55 ◽  
Author(s):  
Don S. Murray ◽  
Walter L. Rieck ◽  
J. Q. Lynd
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Microbial Degradation ◽  
Avena Sativa ◽  
High Nitrogen ◽  
Herbicide Degradation ◽  
Nitrogen Levels ◽  
Degradation Rates ◽  
Residual Herbicide ◽  
Substituted Urea

Phytotoxicity of five substituted urea herbicides 3-(3,4-dichlorophenyl)-1,1-dimethylurea (diuron), 3-(p-chlorophenyl)-1,1-dimethylurea (monuron), 3-phenyl-1,1-dimethylurea (fenuron), 3-hexahydro-4,7-methanoindan-5-yl) −1,1-dimethylurea (norea), and 3-(m-trifluoromethylphenyl)-1,1-dimethylurea (fluometuron) at 0, 10, 100, and 1000 ppm were determined in factorial combination at four urea nitrogen levels of 0, 45, 450, and 900 ppm with three Aspergilli: A. niger, A. sydowi, and A. tamarii. Response interactions were apparent, with all three fungi most tolerant for fenuron and least for diuron. Apparent tolerance order of the three intermediates were: A. niger, norea > fluometuron > monuron; A. sydowi, fluometuron > monuron > norea; and A. tamarii, fluometuron > norea > monuron. Oat (Avena sativa L.) bioassay for residual herbicide toxicity indicated significant differences in herbicide degradation rates between these three fungi at 5, 10, and 20 ppm in Eufaula sand. Diuron was more rapidly degraded than monuron at these levels with fluometuron and norea somewhat intermediate. A. niger was most effective in degradation of these herbicides with A. tamarii greater than A. sydowi. High nitrogen levels in soil organic matter amendment generally favored increased rates of urea herbicide degradation.

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