Pyriminobac methyl

Use pattern Pyriminobac-methyl is a selective, systemic, early... 

Regulatory position The residue definition for pyriminobac-methyl is for the combined E- and Z-isomers. ... 

Pyriminobac-methyl in plant samples (rice grains and rice straw) and soil is recovered by refluxing with aqueous acetone. After removing acetone from the extract, pyriminobac-methyl in the aqueous solution is transferred into n-hexane. The n-hexane layer is dried and evaporated under reduced pressure. The residue from soil... 

Pyriminobac-methyl, fi-isomer, Z-isomer, analytical grade (fiiara Chemical Industries Co., Ltd)... 

Dissolve the residue in 3 mL of n-hexane-ethyl acetate (6 1, v/v) and adsorb on the top of an alumina column bed. Rinse the flask three times with 1 mL of the same solvent mixture and transfer the rinsings to the column. Elute interfering substances with 50 mL of the same solvent mixture and discard the eluate. Then elute pyriminobac-methyl with 150 mL of the same solvent mixture. Collect the eluate in a 300-mL pear-shaped flask and evaporate to dryness under reduced pressure. The residue of the soil sample is dissolved in an appropriate volume of acetone for GC analysis. 

Quantitation is performed by the calibration technique. Construct a fresh calibration curve with pyriminobac-methyl standard solutions (individual isomer) for each set of analyses. 

The recoveries from control samples fortified with pyriminobac-methyl (for individual isomers) at levels of 0.1 mgkg were 96-106% for rice grains, 80-90% for rice straw and 77-92% for soil. The limit of detection was 0.005 mg kg for rice grains, 0.01 mgkg for rice straw and 0.005 mg kg for soil. 

The residue R, expressed in mg kg pyriminobac-methyl (for individual isomers), is calculated using the following equation ... 

Wa = amount of pyriminobac-methyl for y read from calibration curve (ng)... 

Method for extraction of pyriminobac-methyl from soil... 

In the soil metabolism study using [ C]pyriminobac-methyl, most of the residual pyriminobac-methyl in soil was extracted by reflux extraction with acetone. ... 

Extraction of pyriminobac-methyl from rice grain and rice straw... 

For soil samples, sufficient sample cleanup could be conducted even if the alumina column was changed to a Sep-Pak Alumina N cartridge (Waters) by the following process. The entire sample of the dried n-hexane extract (Section 6.2) is introduced into a Sep-Pak Alumina N cartridge, and the column is washed with 50 mL of n-hexane. Subsequently, pyriminobac-methyl is eluted with 3 mL of ethyl acetate, the solvent is evaporate to dryness under reduced pressure and the residue is dissolved in an appropriate volume of acetone for GC analysis. 

Y. Nagai, K. Shinba, A. Yagi, and Y. Yusa, Degradation of a new herbicide, pyriminobac-methyl, in soils, in Abstracts of the 21st Annual Meeting of the Pesticide Science Society of Japan, p. 35 (1996). 

Y. Saito, H. Matsushita, Y. Nagai, Y. Asano, and Y. Yusa, Residue analysis of pyriminobac-methyl... 

There are several commercially available sulfonylurea herbicides that contain a 2-pyrimidine group <2006H(68)561>. These compounds, which function by inhibition of acetolactate synthase (ALS), an enzyme involved in the early stage of branched-chain amino acid synthesis, include sulfometuron-methyl 1095, primisulfuron-methyl 1096, chlorimuron-ethyl 1097, bensulfuron-methyl 1098, ethoxysulfuron 1099, nicosulfuron 1100, and pyrazosulfuron-ethyl 1101. Related nonsulfonylureas include the sulfide pyrftalid 1102 and the ether pyriminobac-methyl 1103. 

Since ALS inhibitory and low-dose herbicides, including the SUs, were not commercially available for the effective control of Echinochloa spp. in transplanted rice when the pyriminobac methyl project was initiated, we focused our studies on... 

Figure 2.5.14 shows a synthetic route for pyriminobac-methyl [28]. The key step is ortho-lithiation reaction (step 3) of compound 21 protected by dimethylacetal and benzylation, followed by regioselective carbomethoxylation at the 2-position with methyl chloroformate via lithiated benzene prepared by n-butyllithium. Through several processes of deacetalization, methoxyimination of the acetyl group and debenzylation, compound 22 is condensed with DMSP 6 to give pyriminobac-methyl 15 [29]. 

At the St. 1, any herbicides were not detected through the period. At the St. 2, fourteen kind of herbicides were detected. The herbicides included cafenstrole, dimepiperate, dimethametryn, esprocarb, mefenacet, pentoxazone, pretilachlor, pyributicarb, pyriminobac-methyl, simetryn, bensulfuronmethyl, daimuron, imazosulfiiron and pyrazosulfuronethyl. The herbicides detection period of this... 

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