HPLC uses new, high efficient particles as the stationary phase, gaining separating capacity. At the same time, liquid chromatographic column has high efficiency and detection sensitivity. Also the flow phase can control and improve the separation process to obtain high selectivity. In addition, due to the use of high-pressure infusion pump, the analysis speed is relatively quicker than classical liquid chromatography. And chiral HPLC is used to lead the enantiomers into chiral environments so that they exhibit physical differences and get separated. It is usually divided into direct and indirect methods. The former is directly separated by chiral mobile phase (CMP) or chiral stationary phase (CSP). The latter uses chiral reagent to carry out precolumn derivatization for the enantiomers, forming some non-enantiomers, which then are separated by conventional stationary phases. For example, we commonly use chiral HPLC to analyze catecholamine substances.
BOC Sciences has experts with extensive experience in chiral HPLC. We use direct methods such as chiral mobile phase separation and chiral solid phase separation as well as indirect methods such as chiral derivatization reagent to make the chiral separation more efficient.
Chiral mobile phase separation adds the chiral reagents to the flow phase and uses normal phase column or reversed phase column to separate the mixture. The principles of action include two possibilities:
1. The solute combines chiral reagents with hydrogen bonding, ion bonding or metallic bonding, generating non-enantiomers clathrate, so the distribution is different in the fixed phase and the flow phase, and gets separated by conventional HPLC Stationary phase.
2. The chiral mobile phase additive (CMPA) interacts with the stationary phase, generating a dynamic CSP. The method can optimize the separation conditions by changing the composition of the CMPA and the flow phase. For example, we use Β-CD, DM-Β-CD and TM-Β-CD as chiral mobile phase additives, and successfully separate and gain D, L-Adrenaline and D, L-Isoproterenol by RP-HPLC.
Chiral solid phase separation binds the chiral compounds to the fixed phase surface. For the enantiomers in the sample, the bonding ability of forming diastereomer clathrate between enantiomers and chiral molecules is different, and that’s how the goal of separation is achieved. To realize chiral recognition, there are at least three interactions between chiral compounds and CSP, that is, the three-point action model. The interactions include hydrogen bonding, electrostatic action, hydrophobic action, π-π action, dipole-dipole action and space effect. For example, we use three (phenyl carbamate) cellulose and amylose as chiral stationary phase, and unite HPLC and ultraviolet detector, successfully separating the adrenaline, isoproterenol and other enantiomers.
The usage of chiral derivative reagent (CDR) is that the enantiomers interact with the derived reagent of high optical purity before the separation, forming non-enantiomers, and we carry out chromatographic separation determination. Differential migration of non-enantiomers in chromatographic system is related to the chiral structure of non-counterpart molecules, to the groups connected with the chiral center and to the separation efficiency of the chromatographic system. The good separation degree of the non-enantiomer derivatives and the high selectivity of derivative reactions depend on the choice of chiral reagent, the structure of the chiral group of the reaction products and the type of chemical bond produced. The greater the differences, the easier they are separated.
BOC Sciences has a proficient command of various chiral HPLC, such as chiral mobile phase separation, chiral solid phase separation and chiral derivatization reagent. We also use multiple techniques (NMR, LCMS, GCMS, X-ray) to analyze compounds after the chiral synthesis is completed. And our turnaround time is fast. Welcome to contact us for more information.