反相高效液相色谱法测定农药中间体3-二氟甲基-1-甲基-1H-吡唑-4-甲酸及其主要杂质的含量

Determination of 3-(Difluoromethyl)-1-methyl-1H-4-carboxylate and Its Impurities in Pesticide Intermediate by Reversed Phase High Performance Liquid Chromatography

建立了反相高效液相色谱法测定农药中间体3-二氟甲基-1-甲基-1H-吡唑-4-甲酸和3-二氟甲基-1-甲基-1H-吡唑-4-羧酸酯含量方法。甲醇和20 mmol/L乙酸铵(pH 5.0)为流动相,采用HC-C18色谱柱,在波长240 nm处检测。该方法在12.387~1238.7 mg/L3-二氟甲基-1-甲基-1H-吡唑-4-甲酸、4.29~214.5 mg/L3-二氟甲基-1-甲基-1H-吡唑-4-羧酸酯范围内线性关系良好[相关系数(r^(2))>0.999],回收率分别为98.84%~100.23%和98.04%~100.37%。

A testing method for the quantitative determination of 3-(difluoromethyl)-1-methyl-1H-4-carboxylate and ethyl-3-(difluoromethyl)-1-methyl-1H-pyrazole-4-carboxylate, which are important pesticide intermediates, by reversed phase high performance liquid chromatography with methanol and ammonium acetate(20 mmol/L, pH = 5.0) solution as mobile phase, HC-C18 column and UV detection at 240 nm, was established. This method has a good linear relationship at range of 12.387~1238.7 mg/L for 3-(difluoromethyl)-1-methyl-1H-4-carboxylate and 4.29~214.5 mg/L for ethyl-3-(difluoromethyl)-1-methyl-1H-pyrazole-4-carboxylate [correlation coefficient(r^(2))>0.999]. The recoveries are 98.84%~100.23% for 3-(difluoromethyl)-1-methyl-1H-4-carboxylate and 98.04%~100.37% for ethyl-3-(difluoromethyl)-1-methyl-1H-pyrazole-4-carboxylate.