High-pressure liquid chromatography column performance

This chapter deals with the properties of high-pressure liquid chromatography columns. It is divided into two sections column physics and column chemistry. In the section on column physics, we discuss the properties that influence column performance, such as particle size, column length and column diameter, together with the effect of instrumentation on the quality of a separation. In the section on column chemistry, we examine in depth the surfaces of modern packings, as well as the newer developments such as zirconia-hased packings, hybrid packings or monoliths. We have also included a short section on... 

HPLC. Is it high-performance liquid chromatography or high-pressure liquid chromatography or something else It s probably easier to consider it a delicate blend of wet-column chromatography and gas chromatography (see Chapters 20 and 24, respectively). 

Since its creation around 1973, modern high-pressure liquid chromatography (HPLC) has played a dominant role in the analysis of pharmaceuticals. It is used in many different applications for example, in content uniformity assays and stability-indicating methods, for the purity profiles of drug substances, or in the analysis of drug metabolism in animals and humans. The heart of all of these assays is the HPLC column. In this chapter, we will describe the fundamental properties of HPLC columns as well as how these properties influence column performance and separation characteristics in pharmaceutical assays. 

Various workers [23-32] have studied the application of high performance liquid chromatography to the determination of PAHs in water samples. Hagenmaier et al. [31] used a reversed phase high-pressure liquid chromatography procedure for the determination of trace amounts of polycyclic aromatic hydrocarbons in water. Different column packing materials were tested, in conjunction with non polar stationary phases of various polarities, for separation efficiency, detection limits and long-term stability. The method was suitable for concentrations as low as 2ng L 1 in a IL sample. Compounds... 

The second question to be answered is What is HPLC This abbreviation is often derived from the term High Performance Liquid Chromatography , though the term High Pressure Liquid Chromatography is often preferred since high performance can also be achieved at low pressure. Just to confuse the issue, is this the pressure created by the resistance to liquid flow through the column or, the pressure at which the column is packed ... 

The process of separation and quantitation of amino acids has been automated. In one automated method, a single cation exchange resin column separates all the amino acids in the protein hydrolysate. The analyzer is capable of detecting as little as 1-2 nmol of an amino acid and a complete analysis can be obtained in about 4 hours. In newer procedures, the complete analysis can be performed in about Ihour and permit detection of as little as 1-2 nmol of an amino acid. Picomole amounts of amino acids can be determined when the separated amino acids are coupled to fluorescent reagents such as o-phthalaldehyde. Amino acid separation and quantitation can also be accomplished by reverse-phase high-pressure liquid chromatography of amino acid derivatives—a rapid and sensitive procedure. 

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