Engineering Commons^™

Continuous Ligand-Assisted Elution Chromatography Applied To Separation Of Rare Earth Elements, Jeremy A. Weinstock, David M. Harvey, N.-H. Linda Wang

The Summer Undergraduate Research Fellowship (SURF) Symposium

Rare earth elements (REEs) are metals used to make many valuable products such as magnets and electronics. Following their extraction from larger materials, REEs are to be separated into their individual components as high purity is required for product manufacture. Purification is very difficult because most (15/17) of the REEs are lanthanides (Ln’s) and Ln ions have the same valence and similar atomic radii. The current industrial process for purifying REEs involves using toxic solvents to perform a series of liquid-liquid extractions. Ling and Wang (2015) proposed a ligand-assisted batch chromatography process to purify Ln’s. The latter approach is a …

Enhancing Silymarin Fractionation Via Molecular Modeling Using The Conductor-Like Screening Model For Real Solvents, Emma C. Brace

Open Access Theses

The market for bio-based products from plant sources is on the rise. There is a global challenge to implement environmentally clean practices for the production of fuels and pharmaceuticals from sustainable resources. A significant hurdle for discovery of comparable plant-derived products is the extensive volume of trial-and-error experimentation required. To alleviate the experimental burden, a quantum mechanics based molecular modeling approach known as the COnductor-like Screening Model for Real Solvents (COSMO-RS) was used to predict the best biphasic solvent system to purify silymarins from an aqueous mixture. Silymarins are a class of flavonolignans present in milk thistle ( Silybum marianum …

Optimization Of Polymer Separation By Gradient Polymer Elution Chromatography, Gideon R. Liem, Linda Nien-Hwa Wang

The Summer Undergraduate Research Fellowship (SURF) Symposium

High Performance Liquid Chromatography (HPLC) has been a versatile separation method for polymers for many years. Analysis of different polymers by HPLC is typically done by utilizing the differential solubility of the polymers by mixing a good solvent and an anti-solvent in various compositions. This method is called Gradient Polymer Elution Chromatography (GPEC). While GPEC has been used extensively, it commonly uses a linear gradient to separate components. Linear solvent gradients consume a lot of solvent and take a relatively long time (> 30 minutes) to complete. The goal of this study is to develop a step gradient from a …

A Generalized Design For Affinity Chromatography Columns, Lee-Wei Kao, Nien-Hwa Linda Wang

The Summer Undergraduate Research Fellowship (SURF) Symposium

In affinity chromatography, an adsorbent with a high selectivity for a target solute is used to isolate the target molecule from other impurities. With sufficient selectivity, the target molecule can be isolated in a highly purified and concentrated state. Common applications of affinity chromatography include Protein A chromatography for antibody purification and Immobilized Metal Affinity Chromatography (IMAC) for protein purification. The well-known design method based on constant-pattern mass transfer zone analysis does not apply to small feed batches, which are insufficient to form constant-pattern frontal waves. Other literature design methods rely on simulation or experimental trials that can be time-consuming …

Elucidation Of Chiral Recognition Mechanisms Of Solutes By Amylose Tris[(S)-Alpha-Methylbenzylcarbamate] Sorbent, Hung-Wei Tsui

Open Access Dissertations

Enantioselective separations of chiral molecules are important in various chemical fields, such as pharmaceuticals and agrochemicals industries. Polysaccharide-based sorbents have been widely used in chiral liquid chromatography. The recognition mechanisms which determine their enantioselectivities are not completely understood.

In this dissertation, the chiral recognition mechanisms of a widely used commercial sorbent, amylose tris[(S)-alpha-methylbenzylcarbamate], for benzoin (B) enantiomers were first studied. The HPLC data for benzoin with pure n-hexane as the mobile phase have been obtained. The behavior of sorbent-solute-hexane systems can be interpreted by considering only sorbent solute two-component interactions. Infrared (IR) spectra showed evidence of substantial hydrogen bonding (H-bonding) …