An aqueous normal-phase high-performance liquid chromatography method was developed to separate cis/trans isomers of 4,5-dihydroxyimidazolidine-2-thione and 4,5-dimethoxyimidazolidine-2-thione on a Luna HILIC 200 Å column containing silica surface covered with cross-linked diol with an eluent acetonitrile/water in the ratio of 95:5 v/v. Changing of the analysis parameters leads to selectivity of cross-linked diol towards analyte with a predominance of adsorption mechanism between the phase and compounds. The separation in reversed-phase and normal-phase modes are unsuccessful. Chromatographic peaks of the cis/trans isomers are identified by the HR-LC–MS and the spectral ratios. The results of the determination of the isomer ratio for 4,5-dihydroxyimidazolidine-2-thione by the HPLC are consistent with the 1H NMR data. The existence of the previously undescribed cis-4,5-dimethoxyimidazolidine-2-thione is confirmed by the HR-HPLC–MS. This method allows providing simultaneous rapid separation and determination of the ratio of isomers in the samples of 4,5-dihydroxyimidazolidine-2-thione and 4,5-dimethoxyimidazolidine-2-thione.

中文翻译：

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通过水相正相 HPLC 模式分离 4,5-二羟基咪唑烷-2-硫酮和 4,5-二甲氧基咪唑烷-2-硫酮的顺/反异构体

开发了一种水性正相高效液相色谱方法，可在含有硅胶表面覆盖的 Luna HILIC 200 Å 柱上分离 4,5-二羟基咪唑烷-2-硫酮和 4,5-二甲氧基咪唑烷-2-硫酮的顺式/反式异构体使用交联二醇，洗脱液乙腈/水的比例为 95:5 v/v。分析参数的改变导致交联二醇对分析物的选择性，其中相和化合物之间的吸附机制占优势。反相和正相模式的分离不成功。顺式/反式异构体的色谱峰由 HR-LC-MS 和光谱比率确定。HPLC 测定 4,5-二羟基咪唑烷-2-硫酮的异构体比的结果与 1H NMR 数据一致。HR-HPLC-MS 证实了先前未描述的顺式-4,5-二甲氧基咪唑烷-2-硫酮的存在。该方法允许同时快速分离和测定 4,5-二羟基咪唑烷-2-硫酮和 4,5-二甲氧基咪唑烷-2-硫酮样品中的异构体比例。