Lin Chen,Li Ge,Qinghui Liang,Zhenbo Zhao,Kedi Yang
The enantioseparation of valsartan enantiomers using chiral eutectic solvents (ESs) as extractants was initially studied. The hydrophobic ESs (LM-DTTA) formed by L-menthol and (+)-Di-p-toluoyl-D-tartaric acid is a suitable chiral medium for the enantioselective extraction of R- and S-valsartan. Four principal parameters affecting chiral extraction, such as phase volume ratio, initial rac -valsartan concentration, extraction temperature, and system pH, were evaluated. The results showed that LM-DTTA has better and higher enantioselectivity levels, and one-step chiral extraction achieved an ee value of S-valsartan up to 91% under the optimized conditions. In addition, this chiral medium can be recycled through simple back-extraction with sodium bicarbonate solution and reused at least five times, giving similar results. This work provides a clear example of enantioseparation of the rac -valsartan via liquid–liquid enantioselective extraction using the LM-DTTA as a novel chiral recognition and separation medium. As a result, the established enantioselective extraction method can efficiently separate the R- and S-enantiomer and promote sustainable development for the production of S-valsartan.
Wen Li,Chunli Gao,Yan Wang,Haiyue Zuo,Yangyang Bian,Cong Li,Shujuan Ma,Yehua Shen,Junjie Ou
Background The fabrication technique of capillary column is the key to the development and application of capillary liquid chromatography (cLC) to improve separation efficiency for analytes. The capillary monolithic column possessed three-dimensionally connected porous or channel structures. Unique porous structure endows excellent permeability and high performance in diverse fields, especially in separation. Thereinto, organic monolithic columns have attracted widespread attention due to their advantages of simple preparation and excellent biocompatibility . However, their separation selectivity needs to be further developed and regulated to apply the separation of more diverse samples. Results A novel polymeric monolithic column was prepared via thermally initiated in situ copolymerization of 2-methyladamantan-2-yl acrylate (MADA) with ditrimethylolpropane tetraacrylate (DTTA) in fused silica . The prepared poly(MADA- co -DTTA) monolith showed adjustable permeability, developed porous structure and high thermal stability . Consequently, it exhibited excellent separation capability of small molecules (alkylbenzenes and polycyclic aromatic hydrocarbons). Especially, when acetonitrile/water (60/40, v/v) was used as the mobile phase , the theoretical plate numbers reached 84,000 plates m −1 for butylbenzene at a linear velocity of 0.5 mm s −1 . Most importantly, the hydrophobicity of the poly(MADA- co -DTTA) monolithic column was regulated via host-guest interaction between adamantyl group and cucurbit [7]uril (CB[7]). Additionally, the poly(MADA- co -DTTA) monolith was further adopted for the analysis of the tryptic digest of proteins from HeLa by cLC-MS/MS. The 33,783 unique peptides and 5,299 proteins were identified on the monolith, which exhibited great separation ability for complex samples. Significance and novelty Due to abundant pore structure and good chemical properties, the poly(MADA- co -DTTA) monolithic column exhibited high performance for the separations of small molecules and biological sample. Meanwhile, owing to the existence of adamantyl-group, CB[7] was immobilized on the poly(MADA- co -DTTA) monolithic column to fabricate poly(MADA- co -DTTA)-CB[7] by host-guest interaction. It is possible to adjust the surface chemistry of the monolithic materials to accommodate more complex analytes.
危险品化学品经营许可证（带存储）