HPLC throughput

A. Metal Oxide Phases IMPROVEMENTS IN DETECTORS IMPROVEMENTS IN HPLC THROUGHPUT... 

This chapter is intended to serve as a general overview of new and emerging HPLC technologies and is divided into four sections simplifying sample preparation, new column technologies, improvements in detectors, and improvements in HPLC throughput. 

Simplifying Sample Preparation New Column Technologies Improvements in Detectors Improvements in HPLC Throughput... 

Both MS and NMR coupling to HPLC have been employed for the analysis of p-carotene isomers and determination of lutein and zeaxanthin isomers in spinach, sweet com, and in retina. Capillary high performance hquid chromatography with stop flow connected to NMR (600 MHz) was used for stracture elucidation of all-trans deoxylutein 11 and its isomers.Efforts are in progress to eliminate the remaining major drawbacks such as obligatory use of deuterated solvents in the mobile phase, poor sensitivity, and low throughput of HPLC-NMR analyses. 

Valko, K., Bevan, C., Reynolds, D. Chromatographic hydrophobicity index by fast-gradient RP-HPLC a high-throughput alternative to log P/log D. Anal. Chem. 1997, 69, 2022-2029. 

Hollosy, F., Valko, K., Hersey, A., Nunhuck, S., Keri, G., Bevan, C. Estimation of volume of distribution in humans from high throughput HPLC-based measurements of human serum albumin binding and immobilized artificial membrane partitioning. J. Med. Chem. 2006, 49, 6958-6971. 

Assessing the resources available for method development should also be done before beginning a project. The resources available include not only HPLCs, detectors, and columns, but also tools for sample preparation, data capture and analysis software, trained analysts, and especially samples representative of the ultimate analyte matrix. Also, it should be considered whether a fast, secondary method of analysis can be used to optimize sample preparation steps. Often, a simple colorimetric or fluorimetric assay, without separation, can be used for this purpose. A preliminary estimate of the required assay throughput will help to guide selection of methods. 

Most importantly, the inefficiency of the chiral HPLC separation of the enantiomers in the penultimate step was detrimental to the speed and throughput required for the project. 

The use of direct UV spectrophotometry to measure sample concentrations in pharmaceutical research is uncommon, presumably because of the prevalence and attractiveness of HPLC and LC/MS methods. Consequently, most researchers are unfamiliar with how useful direct UV can be. The UV method is much faster than the other methods, and this is very important in high-throughput screening. 

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