甲基苯基碳酸酯标准品的制备及其定量分析

Preparation and Quantitative Analysis of Methyl Phenyl Carbonate Standard Sample

利用甲基苯基碳酸酯(M PC)歧化反应的可逆性及逆反应在热力学上有利进行的特点,提出了以碳酸二甲酯(DM C)和碳酸二苯酯(DPC)为原料,在T iO2/S iO2催化下合成DM C与苯酚酯交换反应的中间产物M PC的新方法。反应产物经减压精馏、碱洗、水洗、干燥等精制处理,得到了纯度较高的M PC标准品。采用气相色谱-质谱法对所制备的M PC样品进行定性分析,结果表明其中还含有少量的苯酚和DPC杂质。卡尔.费休水分测定结果表明,M PC样品中的含水量为0.26%(质量分数)。使用常规气相色谱仪,采用OV-101毛细管色谱柱,以苯甲酸乙酯为内标物,对自制的M PC标准品中的微量苯酚和DPC进行定量分析,苯酚和DPC的含量分别为2.04%和1.59%(均为质量分数)。根据杂质分析结果可知自制的M PC标准品的纯度为96.11%。以此作为标准品,解决了对DM C与苯酚酯交换反应的中间产物M PC的准确定量问题。

The preparation and quantitative analytical method for high-purity methyl phenyl carbonate （MPC） was developed. Dimethyl carbonate （DMC） and diphenyl carbonate （DPC） were firstly used as reactants to synthesize MPC catalyzed by TiO2/SiO2 because the disproportionation of MPC is reversible and the reverse reaction is thermodynamically favorable. The high-purity MPC standard sample was obtained by reduced pressure distillation and the removal of minor phenol with dilute sodium hydroxide solution. The qualitative analysis by gas chromatography-mass spectrometry （GC-MS） showed there were minor phenol and diphenyl carbonate in the MPC sample. The mass percent concentration of water in the MPC sample was 0.26%, which was determined by Karl Fischer titration. A gas chromatographic method with an OV-101 capillary column was established for quantifying the minor phenol and DPC in the MPC sample. The quantitative results showed the mass concentrations of phenol and DPC were 2.04% and 1.59%, respectively. The difficulty to analyze MPC, the intermediate product of the transesterification of DMC and phenol, was solved with the self-made MPC standard sample.