HPLC Column Packing Efficiency: For Halogen Bonding Separation Techniques

Graduation Year

2024

Graduation Month

May

Document Type

Thesis

Degree Name

Bachelor of Science

School or Department

Chemistry and Biochemistry

Major

Chemistry – Forensic Chemistry

Faculty Mentor Department

Chemistry and Biochemistry, Department of

Faculty Mentor

Christopher Palmer

Subject Categories

Analytical Chemistry | Organic Chemistry | Physical Chemistry

Abstract

High-performance liquid chromatography (HPLC) is an important technique for the separation and analysis of mixtures of nonvolatile compounds such as proteins, peptides, and pharmaceuticals. Stainless steel tubes (“columns”) uniformly packed with chemically modified small-diameter spherical porous silica particles are essential to the method. As part of the “Halogen Bonding Liquid Chromatography” laboratory research with Dr. Christopher Palmer and Dr. Orion Berryman, silica particles are modified with unique chemistries to further develop HPLC separation capabilities. These particles, generated in relatively small quantities, must be packed into columns to allow evaluation of their performance. The halogen bonding modified silica project aims to pack columns with 200-300mg of modified silica.

Although thousands of commercial HPLC columns are packed and sold yearly, effective packing techniques and methods are generally proprietary. Published studies (Wahab 2017) suggest using a silica slurry that is 5 to 8% silica concentration to produce quality HPLC columns. In the current study, we have developed and optimized methods utilizing minimum quantities of silica, either through lower slurry concentrations or reduced slurry volumes, to pack high-performance columns.

Unmodified spherical silica was used to develop an effective column-packing method utilizing minimum quantities of silica. A series of columns were packed at different silica concentrations and under different packing conditions. Various techniques were investigated to enable a higher-quality column using low slurry concentrations. The packing pressure and solvent used during the packing process are two characteristics of column packing that are optimized for a low silica concentration column to be packed correctly. Being packed properly ensures that silica is packed uniformly throughout the column without any spaces or bubbles in the column itself. The quality of each column is evaluated through specific HPLC methods to measure peak width, shape, and retention time, with optimally packed columns producing narrow and symmetrical peaks. The method's flow rate, oven temperature, and injection volume are varied to allow for the best performance. The final step is to show the method's reproducibility by repacking and testing under the same conditions.

Producing an efficient low silica concentration HPLC column is crucial to the research team's success and will allow a halogen-boding liquid chromatography column to be constructed and commercialized.

Citations

  1. Wahab, M. F., Patel, D. C., Wimalasinghe, R. M., & Armstrong, D. W. (2017). Fundamental and practical insights on the packing of modern high-efficiency analytical and capillary columns. Analytical Chemistry, 89(16), 8177–8191. https://doi.org/10.1021/acs.analchem.7b00931

Honors College Research Project

1

GLI Capstone Project

no

Share

COinS
 

© Copyright 2024 Gabriella Nelson