在Pirkle型的 (S ,S) Whelk O 1与纤维素衍生物型的CDMPC两种手性柱上对六种外消旋萘普生酯进行了对映体分离 ,通过研究烷氧基结构上的差异以及流动相中不同的醇类添加剂对手性识别的影响 ,探讨和比较了外消旋萘普生酯在两种手性固定...在Pirkle型的 (S ,S) Whelk O 1与纤维素衍生物型的CDMPC两种手性柱上对六种外消旋萘普生酯进行了对映体分离 ,通过研究烷氧基结构上的差异以及流动相中不同的醇类添加剂对手性识别的影响 ,探讨和比较了外消旋萘普生酯在两种手性固定相上手性识别的机理 .对于 (S ,S) Whelk O 1,溶质与固定相之间的吸引作用是手性识别的主要因素 ,而对于CDMPC 。展开更多
Enantiomer separation is one of the most important prerequisites for the investigation of environmental enantioselective behavior for chiral pesticides.The enantiomeric separation of three chiral pesticides,indoxacarb...Enantiomer separation is one of the most important prerequisites for the investigation of environmental enantioselective behavior for chiral pesticides.The enantiomeric separation of three chiral pesticides,indoxacarb,lambda-cyhalothrin,and simeconazole,were studied on cellulose tris-(3,5-dimethylphenyl-carbamate)-coated chiral stationary phase(CDMPC-CSP) using high-performance liquid chromatography under normal phase condition.The effects of chromatographic conditions,such as the mobile phase composition including the concentration and type of alcohol modifiers in hexane,flow rate and column temperature,on enantiomer separation were examined.The thermodynamical mechanism of enantioseparation and chiral recognition mechanism were discussed.Better separation were achieved using 20% n-propanol for indoxacarb,2% iso-butanol for lambda-cyhalothrin,and 20% iso-propanol for simeconazole as modifiers in hexane at 25℃ with the selectivity factor(a) of 1.69,1.82 and 1.70,respectively.The resolution factor(Rs) decreased as the flow rate increased from 0.4 to 1.1 ml·min-1.The retention factor(k') and selectivity factor for the enantiomers of analytes decreased as temperature increased.The lna-1/T plots for racemic chiral pesticides were linear in the range of 15-35℃ in hexane/iso-propanol and the chiral separation was controlled by enthalpy.Hydrogen bonding,π-π and dipole-dipole interactions between enantiomers and CDMPC-CSP play an important role in chiral identification,and the fitting of the asymmetric portion of solutes in a chiral cavity or channel of the CSP is also important.展开更多
文摘在Pirkle型的 (S ,S) Whelk O 1与纤维素衍生物型的CDMPC两种手性柱上对六种外消旋萘普生酯进行了对映体分离 ,通过研究烷氧基结构上的差异以及流动相中不同的醇类添加剂对手性识别的影响 ,探讨和比较了外消旋萘普生酯在两种手性固定相上手性识别的机理 .对于 (S ,S) Whelk O 1,溶质与固定相之间的吸引作用是手性识别的主要因素 ,而对于CDMPC 。
基金supported by the "111 Project" from the Ministry of Education of China and the State Administration of Foreign Expert Affairs of China(No.111-2-07)National Science and Technology Major Projects of China(No.2012ZX09103-101-030)and the Project Program of State Key Laboratory of Natural Medicines,China Pharmaceutical University(No.ZJ12009)
基金Supported by China Postdoctoral Science Fund (20090461007)Postdoctoral Research Funding Special Plans of Hunan(2010RC4025)Graduate Innovation Research Project of Hunan (CX2010B295)
文摘Enantiomer separation is one of the most important prerequisites for the investigation of environmental enantioselective behavior for chiral pesticides.The enantiomeric separation of three chiral pesticides,indoxacarb,lambda-cyhalothrin,and simeconazole,were studied on cellulose tris-(3,5-dimethylphenyl-carbamate)-coated chiral stationary phase(CDMPC-CSP) using high-performance liquid chromatography under normal phase condition.The effects of chromatographic conditions,such as the mobile phase composition including the concentration and type of alcohol modifiers in hexane,flow rate and column temperature,on enantiomer separation were examined.The thermodynamical mechanism of enantioseparation and chiral recognition mechanism were discussed.Better separation were achieved using 20% n-propanol for indoxacarb,2% iso-butanol for lambda-cyhalothrin,and 20% iso-propanol for simeconazole as modifiers in hexane at 25℃ with the selectivity factor(a) of 1.69,1.82 and 1.70,respectively.The resolution factor(Rs) decreased as the flow rate increased from 0.4 to 1.1 ml·min-1.The retention factor(k') and selectivity factor for the enantiomers of analytes decreased as temperature increased.The lna-1/T plots for racemic chiral pesticides were linear in the range of 15-35℃ in hexane/iso-propanol and the chiral separation was controlled by enthalpy.Hydrogen bonding,π-π and dipole-dipole interactions between enantiomers and CDMPC-CSP play an important role in chiral identification,and the fitting of the asymmetric portion of solutes in a chiral cavity or channel of the CSP is also important.
