High-pressure liquid chromatography instrumentation

This chapter presents an overview of current trends in high-pressure liquid chromatography (HPLC) instrumentation focusing on recent advances and features relevant to pharmaceutical analysis. Operating principles of HPLC modules (pump, detectors, autosampler) are discussed with future trends. 

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... 

FSIS laboratories also use chemical techniques and instrumentation to identify select antibiotic residues. The tetracyclines of interest are identified by thin layer chromatography. Sulfonamides are detected and quantified by fluorescence thin lay chromatography and confirmed by gas chromatography/mass spectrometry. Amoxicillin and gentamycin are identified and/or quantified by high pressure liquid chromatography. Similar techniques are used to identify ionophores and other antimicrobials of interest. 

The application of atomic spectroscopic instruments as element-specific detectors in chromatography has been reviewed by van Loon More recently, Krull has extensively reviewed their use in high pressure liquid chromatography (HPLC). Atomic spectrometry has found wide acceptance in the field of liquid chromatography because, in most cases, the fractions can be directly analysed after elution from the column. However, it is possible to use the technique for the analysis of solid samples without first dissolving the matrix. This is particularly useful after electrophoresis, where the fractions are fixed either in a gel or on paper. Kamel et al. have shown that it is possible to cut the appropriate sections and insert them into the carbon furnace for analysis. The disadvantage of this approach is that the precision is usually poorer (about 10%) and it is difficult to calibrate the instrument. Nevertheless, this approach is very useful if it is used for qualitative speciation. 

The analysis of individual chemical constituents in distilled spirits currendy is performed using gas chromatography (gc) and high pressure liquid chromatography (hplc). Although other types of instrumental analyses have yielded much information regarding the chemical constituency of distilled spirits, the combination ofgc and hplc has allowed hundreds of different chemical components of distilled spirits to be individually identified and accurately quantified. 

Only the current cost of the equipment prevents this instrumentation from becoming the toxicologist s prime tool. High pressure liquid chromatography is also destined for a long future in toxicology. The ability to separate polar metabolites is an outstanding problem that could be overcome by this technique. 

A wide array of laboratory techniques and instrumentation is used in forensic studies. This includes ultraviolet, infrared, and visible spectrophotometry neutron activation analysis gas chromatography and mass spectrophotometry high pressure liquid chromatography and atomic absorption spectrophotometry. The techniques and instrumentation chosen depend on the type of sample or substance to be examined. 

As described earlier, the revolution in high pressure liquid chromatography arose from a number of factors a better understanding of the theory of liquid chromatography, development of new supports and the development of new instrumentation specifically designed for use in the high pressure environment. 

UV-visible spectra were obtained using a Cary 118C spectrophotometer. Insertion probe mass spectra were obtained with a Dupont 21-49IB mass spectrometer, the FAB spectra with a VG MM-ZAB instrument, and the FD spectra with a JEOL DX-300 mass spectrometer. High pressure liquid chromatography measurements were made with a Waters instrument fitted with dual channel (405 and 546 nm) optical detection and using C18 analytical and semipreparative columns. 

There are many types of automation equipment for SPE. They include semiautomated instruments, which are instruments where some intervention is required workstations, which carry out the entire SPE operation without intervention, including on-line analysis by GC and high-pressure liquid chromatography (HPLC) and customized SPE, which are robotic systems that are capable of many activities besides SPE and are custom designed for the user. 

This section describes the various components of an ion chromatography instrument, their function, and some general points for upkeep of the chromatograph. New IC users can use the information to understand how an instrument is built and to recognize the parts of the instrument that may need maintenance. The hardware is similar to that used for high pressure liquid chromatography (HPLC) but does have important differences. Readers who are familiar with HPLC will recognize the similarity and the differences to IC hardware [7-9]. 

High-performance liquid chromatography (HPLC), also known as high-speed liquid chromatography and high-pressure liquid chromatography, has developed over recent years as a result of advances in instrumentation and column packings. 

---