Highly sensitive trivalent copper chelate-luminol chemiluminescence system for capillary electrophoresis chiral separation and determination of ofloxacin enantiomers in urine samples

A simple,fast and sensitive capillary electrophoresis（CE） strategy combined with chemiluminescence（CL） detection for analysis of ofloxacin（OF） enantiomers was established in the present work.Sulfonated p-cyclodextrin（β-CD） was used as the chiral additive being added into the running buffer of luminol-diperiodatocuprate（Ⅲ）（K[Cu（HIO6）2],DPC） chemiluminescence system.Under the optimum conditions,the proposed method was successfully applied to separation and analysis of OF enantiomers with the detection limits（S/N=3） of 8.0 nM and 7.0 nM for levofloxacin and dextrofloxacin,respectively.The linear ranges were both 0.010-100 μM.The method was utilized for analyzing OF in urine;the results obtained were satisfactory and recoveries were 89.5-110.8%,which demonstrated the reliability of this method.This approach can also be further extended to analyze different commercial OF medicines.

Sucrose as chiral selector for determining enantiomeric composition of phenylalanine by UV-vis spectroscopy and chemometrics

The determination of enantiomeric composition by partial least squares （PLS） modeling of UV-vis spectral data was investigated for samples of phenylalanine （phe） using sucrose as a chiral auxiliary. And a new data preprocess method, reference band normalization, was introduced to eliminate the spectral variations due to the changes of total concentration of phe. The determination coefficient （R2） and the standard error of calibration set （SEC） of 13 standard samples are 0.9987 and 0.0128 respectively. The standard error of validation set （SECV） of 7 validation samples is 0.0049. The standard error of predict （SEP） of 6 blind samples for evaluating the robustness of the model is 0.0366. The regression model is robust to determine enantiomeric composition when total concentration varied. It is demonstrated that the reference band normalization is a convenient method of compensating for variations in total concentrations without knowing that in advance.

Chiral pillar[n]arenes:Conformation inversion,material preparation and applications

Chiral pillar[n]arenes have shown great research value and application prospect in construction of chiral materials and chiral applications,due to their inherent planar chiral configurations,chiral recognition ability,easy modification and highly symmetric hydrophobic cavity.This review systematically summarized the conformation inversion factors of planar chiral pillar[5]arenes(pR/p S),such as solvents,temperature,substituent size,alkyl chains,chiral and achiral guest molecules.We firstly introduced the applications of chiral pillar[n]arenes for constructing chiral materials and pointed out that planar conformation inversion showed a great potential role in constructing chiral materials.Then,we mainly concluded the chiral applications of chiral and planar chiral pillar[n]arenes like chiral enantiomer analysis by circular dichroism,electrochemistry or chiral fluorescence sensing.From this review,we found that the inherent planar chiral conformation of chiral pillar[n]arenes have played a very important role in chiral field in the future.