Monolithic Silica Stationary Phases in Liquid Chromatography

Department of Chemistry, Jamia Millia Islamia (Central University), New Delhi - 110025, India.
Journal of chromatographic science (Impact Factor: 1.36). 08/2009; 47(6):432-42. DOI: 10.1093/chromsci/47.6.432
Source: PubMed


During the last few decades, monolithic stationary phases (based on silica and polymers) have been used for fast separations in high-performance liquid chromatography (HPLC) and capillary electro-chromatography (CEC). The present article describes the preparation, properties, and applications of these stationary phases. Attempts have been made to discuss the preparation of reversed-phase monolithic HPLC columns and CEC capillaries. The chromatographic properties of these phases have been described. The applications included their use in HPLC and CEC modalities of liquid chromatography. The optimization of separations of various molecules on these phases has been discussed. Efforts were also made to predict the future perspectives of monolithic stationary phases.

Download full-text


Available from: Hassan Y. Aboul-Enein
  • [Show abstract] [Hide abstract]
    ABSTRACT: The present study reports one of the very first analytical applications of the new narrow-bore monolithic column, FastGradient Chromolith (50mm x 2.0mm i.d.). The three major methylxanthines (theobromine, theophylline and caffeine) were separated rapidly and determined simultaneously in various real samples. Based on the unique characteristics of this novel monolithic column the analytes were separated efficiently (R(s)>3.0) in less than 5min at a low flow rate of 0.5mLmin(-1) and using a low volume fraction of organic solvent (5% acetonitrile (ACN) in water) in the mobile phase. UV detection was carried out at 274nm. The separation was optimized in terms of mobile phase composition, flow rate and injection volume, while the method was validated for linearity, detection and quantitation limits, within and day-to-day precision, accuracy and ruggedness. Its applicability was demonstrated by analyzing a variety of real samples including beverages, soft drinks, herbal products and pharmaceuticals. Compared to a well-established monolithic (Performance Chromolith 100mm x 4.6mm i.d.) and a particulate reversed phase column (Hypersil ODS 5microm 150mm x 4.6mm i.d.), the narrow-bore FastGradient column offered satisfactory performance, faster analysis time and drastic reduction in the consumption of mobile phase and organic solvents.
    No preview · Article · Jun 2010 · Talanta
  • [Show abstract] [Hide abstract]
    ABSTRACT: In recent years, a trend of change has been observed within pharmaceutical industry. As modern drug discovery has reached a remarkable level of complexity and drugs need to be discovered, developed and produced against strict timelines and within cost- and regulatory constraints, industry seeks "lean" solutions to increase productivity. Among them, increasing the sample throughput of the ever-growing number of necessary (routine) analyses has become a popular target to cut precious time. For the last thirty years, High-Performance Liquid Chromatography (HPLC) has been the leading technology when it comes to various analyses in pharmaceutical industry; however, its necessity of serial analyses taking typically 10-45 min has been a sample throughput-limiting barrier. Lately, the fundamentals of HPLC have been exploited to raise new technologies that can speed up analyses to ground breaking limits, without compromising separation efficiency. This paper reviews some promising technologies, i.e. totally porous sub-2microm particles accompanied by pressures up to 1000 bar (Ultra-Performance Liquid Chromatography or UPLC), fused-core particle technology, monolithic supports and High Temperature Liquid Chromatography (HTLC), having the potential to take LC to the next level in pharmaceutical industry. As each analytical method has its own demands, the advances of the above technologies are discussed for different applications in pharmaceutical analysis where high-throughput analysis can be meaningful, i.e. in a drug discovery and development setting, and in quality operations. Both chemical and biological pharmaceuticals are considered. We discuss the perspectives of these technologies and their realizations up to now in high-throughput pharmaceutical analysis.
    No preview · Article · Jul 2010 · Combinatorial chemistry & high throughput screening
  • [Show abstract] [Hide abstract]
    ABSTRACT: Anion exchange monolithic chromatography is increasingly becoming a prominent tool for plasmid DNA purification but no generic protocol is available to purify all types of plasmid DNA. In this work, we established a simple framework and used it to specifically purify a plasmid DNA model from a clarified alkaline-lysed plasmid-containing cell lysate. The framework involved optimising ligand functionalisation temperature (30-80°C), mobile phase flow rate (0.1-1.8mL/min), monolith pore size (done by changing the porogen content in the polymerisation reaction by 50-80%), buffer pH (6-10), ionic strength of binding buffer (0.3-0.7M) and buffer gradient elution slope (1-10% buffer B/min). We concluded that preferential pcDNA3F adsorption and optimum resolution could be achieved within the tested conditions by loading the clarified cell lysate into 400nm pore size of monolith in 0.7M NaCl (pH 6) of binding buffer followed by increasing the NaCl concentration to 1.0M at 3%B/min.
    No preview · Article · Oct 2010 · Journal of chromatography. B, Analytical technologies in the biomedical and life sciences
Show more