【摘要】 为探索溶剂或单体中微量杂质分析方法,在SP—2305E型色谱仪上设计了二维气相色谱流程,采用在线微型六通阀进行流路切换,用微型中间陷阱进行“再进样”.用自制石墨化碳黑毛细管柱和不同极性的填充预柱,对氯甲烷中微量杂质进行了分离和定性.更多还原

【Abstract】 A two-dimensional gas chromatography system has been designed for the micro-analysis of impurities in solvents or monomers. Two columns that are different in polarity were used in this system for the separation and the qualitative analysis of impurities in chloromethane. One of the columns is a home-made graphite carbon black glass capillary column and the other is a packed pre-column.In a modified SP-2305E model Gas Chromato-graph, glass capillary column was used as the main separation column with FID. In the same thermostat oven there was a packed pre-columu with TCD. The two separated gas ways of the two columns were joined by a micro-sixway-valve The intermediate trap which was a stainless steel tube with 0.3-0.5mm inner diameter was coupled to the micro-sixway-valve diagonally. The coolant was liquid nitrogen. The collected components were heated with a large current (8A) at lower voltage (6V) for 0.3-0.5 second to do the "re-injection" instantaneously.Twenty impurities in chloromethane have been identified by means of GC-MES (Micro Wave plasma Emission Spectra), GC-MS, and pure component identification by two columns. These were methanol, chloroform and toluene etc. The front part, tail part and "heart-cutting" of the main chloromethane peak leaving the pre-column were collected and re-injected, respectively. Bad resolution peaks and an unknown peak were also switched and re-injected, respectively. Six figures, one table and six references are given.更多还原