title: [The ultraviolet absorption spectra of pyrazoles and 1-carboxamidepyrazoles and their application].
abstract: The ultraviolet absorption spectra of pyrazoles and 1-carboxamidepyrazoles were studied. The results indicated that substitution in the 3 or the 5 position it leads to a bathochromic shift of the position of the maximum absorption by about 3-4 nm, whereas in the 4 position leads to a much larger bathochromic shift (> 10 nm). The introduction of carboxamide causes a bathochromic shift of the position of the maximum absorption by about 20-26 nm. Its also leads to an increase in molar extinction coefficient by about 2-3 times. So UV methods were established for determining the contents of pyrazoles and their derivations. Using these methods, the content of 3,4-dimethylpyrazole phosphate (DMPP) in stabilized urea was determined to be 1.15% of urea-N, the hydrolytic half lives of 1-carboxamide-3-methylpyrazole (CMP) in water solution at 20, 25 and 30 degrees C were 48, 30 and 18 h, respectively, and the extraction percentage of nitrification inhibitor 3-methylpyrazole phosphate (MPP) in 3 soils by 3 different extractants were ranged from 63.2% to 89.2%.
authors.affiliation: Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, China. shiyunfeng8189@yahoo.com.cn
authors.forename: Yun-Feng
authors.initials: YF
authors.lastname: Shi
authors.forename: Zhi-Jie
authors.initials: ZJ
authors.lastname: Wu
authors.forename: Li-Jun
authors.initials: LJ
authors.lastname: Chen
authors.forename: Guang
authors.initials: G
authors.lastname: Chen
authors.forename: Yao-Peng
authors.initials: YP
authors.lastname: Liu
authors.forename: Li-Li
authors.initials: LL
authors.lastname: Zhang