title: Chiral separation of neonicotinoid insecticides by polysaccharide-type stationary phases using high-performance liquid chromatography and supercritical fluid chromatography.
abstract: The enantiomeric separations of three neonicotinoid insecticides (identified as compounds 1, 2, and 3) were performed on three polysaccharide-type chiral columns, that is, Chiralcel OD-H, Chiralpak AD-H, and Chiralpak IB, by high-performance liquid chromatography (HPLC) and supercritical fluid chromatography (SFC). Effects of the modifier percentage and column temperature on chiral recognitions of chiral stationary phases were also studied. Both 1 and 2 could be resolved on all three columns selected, with the highest R(s) values obtained on Chiralpak AD-H and Chiralcel OD-H, respectively. However, satisfactory separation of the four stereoisomers of 3 was only achieved on Chiralcel OD-H. Considering the effects of ethanol on the values of k, α, and R(s), we concluded that hydrogen bonding, π-π, and/or dipole-dipole interactions might be all responsible for the chiral separation. In comparison to HPLC, a shorter run time was achieved for 1 and 2 by SFC. However, 3 could not be stereoselectively resolved using SFC. On the basis of the calculated thermodynamic parameters, we found that the separation processes of enantiomers of 1 and 2 were entropy controlled and enthalpy controlled, respectively.
authors.affiliation: Research Center of Environmental Science, College of Biological and Environmental Engineering, Zhejiang University of Technology, Hangzhou, China.
authors.forename: Cheng
authors.initials: C
authors.lastname: Zhang
authors.forename: Lixia
authors.initials: L
authors.lastname: Jin
authors.forename: Shanshan
authors.initials: S
authors.lastname: Zhou
authors.forename: Yifan
authors.initials: Y
authors.lastname: Zhang
authors.forename: Shuoli
authors.initials: S
authors.lastname: Feng
authors.forename: Qinyan
authors.initials: Q
authors.lastname: Zhou
mesh_terms: D000688:Amylose / Q000031:analogs & derivatives* / Q000032:analysis / Q000737:chemistry; D002482:Cellulose / Q000031:analogs & derivatives* / Q000032:analysis / Q000737:chemistry; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D025924:Chromatography, Supercritical Fluid / Q000379:methods*; D019277:Entropy; D006860:Hydrogen Bonding; D007306:Insecticides / Q000032:analysis / Q000737:chemistry*; D048448:Phenylcarbamates / Q000032:analysis / Q000737:chemistry*; D011134:Polysaccharides / Q000737:chemistry*; D013237:Stereoisomerism; D013696:Temperature
chemical_list: C504080:3,5-dimethylphenylcarbamate; D007306:Insecticides; D048448:Phenylcarbamates; D011134:Polysaccharides; C065943:cellulose tris-3,5-dimethylphenyl-carbamate; C080033:Chiralpak AD; D002482:Cellulose; D000688:Amylose