Liquid chromatographic columns, performance evaluation

The silanophilic character of 16 reversed-phase high-performance liquid chromatographic columns was evaluated with dimethyl diphenycyclam, a cyclic tetraza macrocycle [101]. The method is rapid, does not require the removal of packing material, and uses a water-miscible solvent. The results demonstrate two points first, cyclic tetraza macrocycles offer substantial benefits over currently used silanophilic agents second, the method can easily differentiate the performance of various columns in terms of their relative hydrophobic and silanophilic contributions to absolute retention. 

Several high performance liquid chromatographic columns were evaluated according to their capabilities to separate and release the MIC-Fluram fluorophor. Reverse phase, normal partition, and amine bonded columns were tested. The reverse phase columns performed the separation and analysis more proficiently than the other columns. A Variarv CH-10 column was the best column from among the several ones that were tested. 

Ascah, T., Kallury, K., Szafranski, C. Corman, S., and Liu, F., Characterization and high performance liquid chromatographic evaluation of a new amide-functionalized reversed-phase column, /. Liq. Chromatogr. Relat. Technol, 19 (17,18), 3049, 1996. 

Viehauer S. et al., 1995. Evaluation and routine application of the novel restricted-access precolumn packing material Alkyl-Diol Silica Coupled-column high-performance liquid chromatographic analysis of the photoreactive drug 8-methoxypsoralen in plasma. J Chromatogr B 666 315. 

The solvent delivery system is responsible for delivering the pressurized mobile phase with the desired composition and chosen flow rate to the head of the column. To achieve this goal a number of components work together under the supervision of the system computer or microprocessors to achieve the tight specifications typical of a modem liquid chromatograph. Table 5.2 [15-19]. Suitable tests for performance evaluation of solvent delivery systems are briefly described at the end of section 5.2.2. In retention terms a relative standard deviation of better than 0.15% for retention factors under normal operating conditions is expected. 

High Performance Liquid Chromatography. All separations were performed using an Altex Scientific (1780 Fourth Street, Berkeley, CA 94710) Model 320 Advance Research Chromatograph, consisting of a model lOOA dual piston analytical pump, a Model 153 UV detector, a Model 210 injection valve, and a Model 155 recorder. The columns (600 x7.5mm) evaluated were the Spherogel TSK-SW-2000 and SW-3000 (Altex). Unless otherwise stated, all separations were carried out at 23 - 25 . 

In order to evaluate a detector for use in liquid chromatography (LC), accurate performance criteria or specifications must be provided by the manufacturers. This is necessary to assess the pertinence of a given detector for a particular chromatographic separation, and/or to permit a rational comparison with other detectors. More important, such performance criteria will allow the optimum column to be designed to achieve a particular separation for which the detector is to be used. It follows that the performance data provided for each detector must be presented in a standard form and given in standard units which will be consistent between detectors that function on widely different principles. The principal characteristics of a detector that will fulfill these requirements are given as follows. 

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