分别采用反相液相色谱法、黄原酸盐法，测定了甲代混剂中的甲基硫菌灵和代森锰锌含量，并进行了热贮稳定性的研究。试验结果表明：该方法准确度（９９－３６ ％ ～１００－０６ ％ ） 和精确度（Ｓｘ ＝ ０－２９ ，０－５７ ，ＣＶ＝０－７８ ％ ，０－６７％ ） 符合要求。样品热贮后代森锰锌单剂热稳定性较差，相对分解率为１４－０１ ％ ；甲基硫菌灵热稳定性良好，相对分解率为０－５６ ％ ；甲代混剂热稳定性介于两者之间，相对分解率为８－０２ ％ ；甲代混剂热贮前后悬浮率分别是７５－７０ ％ 和６７－４５ ％ 。 The contents of thiophanate-methyl and mancozeb in methyl-ethyl acetate mixtures were determined by reversed-phase liquid chromatography and xanthate method, respectively. The thermal storage stability was also studied. The test results show that the method meets the requirements of accuracy (99-36% ~ 100%) and accuracy (Sx = 0-29, 0-57, CV = 0-78%, 0-67%). The thermal stability of single-agent mannitol after thermal storage was poor, the relative decomposition rate was 14-01%, the thiophanate-methyl was good and the relative decomposition rate was 0-56%. The thermal stability Between the two, the relative decomposition rate of 8-02%; A mixture of heat storage before and after the suspension rate was 75-70% and 67-45%.