【作者】 崔莹；

【导师】 朱振中； 董伟；

【作者基本信息】 江南大学 ， 分析化学， 2009， 硕士

【摘要】 本文以3-巯丙基三甲氧基硅烷为偶联剂,将聚N-异丙基丙烯酰胺键合到多孔质硅胶基质表面,制得聚N-异丙基丙烯酰胺硅胶键合固定相(SI-PNIPAM)填料,并通过红外光谱对其进行了表征。以甲醇-水为二元流动相,用多环芳烃、碱性物质、二甲苯异构体考察了聚N-异丙基丙烯酰胺硅胶键合固定相(SI-PNIPAM)的一般色谱性能及其在分离极性物质、碱性物质、同分异构体时所表现的温度响应性,并研究了该固定相在化妆品防腐剂、维生素E胶丸测定中的应用。该固定相具有较好的色谱性能,在分离多环芳烃时与ODS柱相比出峰顺序相同,保留时间大为提前;且由于酰胺基中氮原子产生的屏蔽效应大大减弱了残留硅羟基的影响,从而对碱性物质的分离取得较好的结果,峰形较对称。该固定相与功能高分子聚N-异丙基丙烯酰胺一样具有良好的温敏特性,以甲醇-水(30 : 70)为流动相,在28℃~32℃时发生了相转变,由亲水性构象转变为疏水性构象,因而改变了色谱分离顺序。由于相转变行为随温度变化的响应性较慢,所以试验中只有具有较大极性并有显著极性差异的一类物质,其相转变行为才较为明显。在甲醇-水(55 : 45)的流动相中,SI-PNIPAM对四种苯甲酸酯类防腐剂实现了基线分离,峰形对称。采用超声离心提取并过柱净化的样品处理方法对化妆品中的防腐剂进行提取,并比较了甲醇与无水乙醇-水两种提取剂的提取效果。结果表明,无水乙醇的提取效果较好,各组分线性关系良好,重现性好,加标回收率高。该固定相对市售膏霜、乳液类化妆品进行了实测,获得了较满意的结果,可作为定性定量检测化妆品中防腐剂等成分的一种新方法。以SI-PNIPAM为分析柱的反相高效液相色谱法可应用于测定维生素E胶丸中VE的含量,此法方便、准确、快速,重现性好。该固定相还可作为正相色谱分析,对天然维生素E有较好的分离效果。更多还原

【Abstract】 In this study,poly-(N-isopropyl-acrylamide) bonded stationary phase (SI-PNIPAM) was prepared by reacting silica gel with 3-mercaptopropyltrimethoxysilane.Characterization of the prepared packing was carried out with Fourier transform infrared (FT-IR) spectroscopy. The application of SI-PNIPAM was researched by testing with polycyclic aromatic hydrocarbons、basic compounds and xylene isomers using methanol-water as a binary mobile phase in the field of chromatography . The thermal-responsibility of SI-PNIPAM for separating polarity compounds、basic compounds and isomers was also discussed . Practical application of SI-PNIPAM for the determination of preservatives cosmetics and vitamin E was researched finally.The results showed that the stationary phase has excellent chromatographic properties which greatly advanced the retention time and kept the same order for separation of polycyclic aromatic hydrocarbons by comparing with the result on ODS-BP. It also can be seen that SI-PNIPAM has excellent thermal-responsibility as well as PNIPAM. Using methanol-water(30 : 70) as mobile phase ,when a small temperature changed in the vicinity of 32℃, a narrow range of temperature , phase transition behavior of SI-PNIPAM will come to happen by changing the hydrophilic conformation for the hydrophobic conformation which lead to diferent order for separation in 28℃~ 32℃.However,the phase transition behavior responsing to temperature changed slowly,only the polar compounds with distinct difference in polarity had obvious performance in phase transition behavior.Preservatives of p-hydroxybenzoic acid esters could achieve baseline separation as well as symmetrical peaks on SI-PNIPAM in the mobile phase of methanol-water (55 : 45).Preservatives were extracted from cosmetics by the step of ultrasonic extraction and centrifugation,then Alumina column purification. Extraction was discussed by comparing the two extraction agents of methanol and ethanol–water.The results showed that ethanol–water was the better extraction agent for preservatives of p-hydroxybenzoic acid esters.The results for the recovery,reproducibility.the linear range and CV were good.The method which consisted of the preservative extraction and chromatographic separation on SI-PNIPAM could be applied to determine the preservatives in cosmetic preparations.The actual determination of preservatives in cosmetic sales obtained a more satisfactory result by using this new method.Using SI-PNIPAM as stationary phase, a RP-HPLC method has been established for the quantitative determination of Vtiamin E in capsule by.Results showed that the method was convenient,rapid,accurate and reliable. SI-PNIPAM used as a nomal-phase column could be applied for analysis of natural vitamin E with good separation.更多还原