研究了吡唑类化合物和1-甲胺酰基吡唑类化合物的紫外吸收光谱。结果表明,3位和5位的取代使吡唑的最大吸收波长红移3-4nm,而4位的取代能够引起较大的红移(>10nm)。甲胺酰基的引入可使吡唑类化合物的最大吸收波长红移20-26nm,最大消光系数提高2-3倍。基于此,建立了快速测定吡唑类化合物含量的紫外分光光度法,并测定了长效尿素中3,4-二甲基吡唑磷酸盐(DMPP)的含量为尿素-N的1.15%,1-甲胺酰基-3-甲基吡唑(CMP)在水溶液中水解的半减期在20,25和30 ℃下分别为48,30和16 h,应用不同提取剂对三种土壤中硝化抑制剂3-甲基吡唑磷酸盐(MPP)的提取率为63.2%-89.2%。

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 20-26nm.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℃ were 48,30 and 16h,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%.