Abstract The microreactor based hydroxylation process of 1,2,4-trichlorobezene for producing 2,5-dichlorphenol, the key intermediate of dicamba, is energy efficient and cost effective. But the 2,5-dicholorphneol is present in a mixed state after production. The reaction mixture contained the main by-product 2,4-dichlorophneol, low-content by-product 3,4-dichlorophneol, and other impurities. The difficulty in separation and analysis limits the application of this process widely. The current work aimed at establishing effective analysis methods by gas chromatography (GC) and high performance liquid chromatography (HPLC). The GC method was not able to separate 2,5-dichlorophenol and 2,4-dichlorophenol completely, but the developed HPLC method worked efficiently. The linear correlation coefficients of 2,5-dichlorophenol and 2,4-dichlorophenol were both higher than 0.999, and the average recovery was 100.33% for 2,5-dichlorophenol and 100.13% for 2,4-dichlorophenol, respectively. The relative standard deviations from precision tests were both less than 1%. The contents of 2,5-dichlorophenol and 2,4-dichlorophenol were determined with external standard method. The HPLC method has the advantages of simple operation, good separation efficiency, high accuracy and precision, and was successfully applied for both qualitative and quantitative analysis of 2,5-dichlorophenol and 2,4-dichlorophenol of the sample solution.

中文翻译：

---

高效液相色谱和气相色谱分析麦草畏关键中间体的方法开发

摘要 基于微反应器的 1,2,4-三氯苯羟基化生产麦草畏的关键中间体 2,5-二氯苯酚的工艺节能且具有成本效益。但2,5-二氯酚在生产后以混合状态存在。反应混合物中含有主要副产物2,4-二氯苯酚、低含量副产物3,4-二氯苯酚和其他杂质。分离和分析的困难限制了该工艺的广泛应用。目前的工作旨在建立有效的气相色谱 (GC) 和高效液相色谱 (HPLC) 分析方法。GC 方法无法完全分离 2,5-二氯苯酚和 2,4-二氯苯酚，但开发的 HPLC 方法有效。2,5-二氯苯酚与2的线性相关系数，4-二氯苯酚均高于0.999，2,5-二氯苯酚的平均回收率为100.33%，2,4-二氯苯酚的平均回收率为100.13%。精密度测试的相对标准偏差均小于 1%。2,5-二氯苯酚和2,4-二氯苯酚的含量采用外标法测定。HPLC法具有操作简单、分离效率好、准确度和精密度高等优点，已成功应用于样品溶液中2,5-二氯苯酚和2,4-二氯苯酚的定性和定量分析。4-二氯苯酚采用外标法测定。HPLC法具有操作简单、分离效率好、准确度和精密度高等优点，已成功应用于样品溶液中2,5-二氯苯酚和2,4-二氯苯酚的定性和定量分析。4-二氯苯酚采用外标法测定。HPLC法具有操作简单、分离效率好、准确度和精密度高等优点，已成功应用于样品溶液中2,5-二氯苯酚和2,4-二氯苯酚的定性和定量分析。