Various zirconia stationary phases were prepared by modification with di-dentate Lewis bases: dodecyl-N,N-diacetic acid（RNCC）, dodecyl-N-acetic acid-N-methyleneposphonic acid（RNCP）, dodecyl-N,N-dimethylenephosphon...Various zirconia stationary phases were prepared by modification with di-dentate Lewis bases: dodecyl-N,N-diacetic acid（RNCC）, dodecyl-N-acetic acid-N-methyleneposphonic acid（RNCP）, dodecyl-N,N-dimethylenephosphonic acid（RNPP） and dodecencylsuccinic acid（RCC）. The color reaction of RNPP-ZrO2 and RNCP-ZrO2 with ammonium molybdate indicate there are free phosphonic groups on the surface of the stationary phases, and the FTIR spectra of RNCC-ZrO2 and RNCC-ZrO2 indicate there are free carboxyl groups. The RCC-ZrO2 is far more stable than RNCC-ZrO2 under alkali station. The results of color reaction, FTIR spectra and the stability test of stationary phases suggest that, due to the chelating effect, RNCC, RNCP and RNPP adsorb on zirconia with only one carboxyl or phosphonic group, however, RCC adsorb on zirconia with two carboxyl groups.展开更多
文摘Various zirconia stationary phases were prepared by modification with di-dentate Lewis bases: dodecyl-N,N-diacetic acid（RNCC）, dodecyl-N-acetic acid-N-methyleneposphonic acid（RNCP）, dodecyl-N,N-dimethylenephosphonic acid（RNPP） and dodecencylsuccinic acid（RCC）. The color reaction of RNPP-ZrO2 and RNCP-ZrO2 with ammonium molybdate indicate there are free phosphonic groups on the surface of the stationary phases, and the FTIR spectra of RNCC-ZrO2 and RNCC-ZrO2 indicate there are free carboxyl groups. The RCC-ZrO2 is far more stable than RNCC-ZrO2 under alkali station. The results of color reaction, FTIR spectra and the stability test of stationary phases suggest that, due to the chelating effect, RNCC, RNCP and RNPP adsorb on zirconia with only one carboxyl or phosphonic group, however, RCC adsorb on zirconia with two carboxyl groups.
文摘以双[-6-氧-(-3-脱氧柠檬酸单脂-4)]-β-环糊精键合全多孔型硅珠为HPLC手性固定相,以甲醇和三氟乙酸-三乙胺缓冲液为流动相,探究流动相比例、缓冲液浓度、缓冲液p H值、检测波长、色谱柱温和流速等条件对山莨菪碱二个外消旋体拆分效果的影响。在最佳分离条件(三氟乙酸浓度2mmol/L,p H值4.1,V_(甲醇)∶V_(缓冲液)=50%∶50%,流动相流速为0.5 m L/min,色谱柱温20℃,检测波长235nm)下山莨菪碱混合物被拆分为二个外消旋体,实现了基线分离,Rs达4.20;并得到了四个对映异构体拆分的结果。
