Chromatographic parameters

Gombining equations 12.13 through 12.15 gives the height of a theoretical plate in terms of the easily measured chromatographic parameters and w. 

Chromatographic separations rely on fundamental differences in the affinity of the components of a mixture for the phases of a chromatographic system. Thus chromatographic parameters contain information on the fundamental quantities describing these interactions and these parameters may be used to deduce stabiUty constants, vapor pressures, and other thermodynamic data appropriate to the processes occurring in the chromatograph. 

The chromatographic parameters were compared with calculated H2O-u-octanol logP value (2.23) (by CLOGP program) (96JC(A)135). 

The first chromatographic parameter that was employed for solute identification was the corrected retention volume (V r). However, the measurement of (V r) is not as straightforward as it might seem. Consider equation (11), which for convenience will be reiterated. 

Electronic flow controllers are becoming more popular on modem instruments and are essential where chromatographic parameters are entered through a keyboard [4-6,10,11]. They are... 

Meier Augenstein, W., Watt, P. W. and Langhans, C. D. (1996) Influence of gas chromatographic parameters on the measurement of 13C/12C isotope ratios by gas liquid chromatography combustion isotope ratio mass spectrometry. I. Journal of Chromatography, A 752, 233 241. 

A mixture of acetyl acetone, 1-nitronaphthalene, and naphthalene has been proposed for evaluating reversed-phase packing material [102]. This reveals the usual optimum kinetic chromatographic parameters (the naphthalene peak), the degree of activity or end-capping status of the column (the ratio of the 1-nitronaphthalene and naphthalene retention times) and trace metal activity (the shape and intensity of the acetylacetone peak). 

Reliable flame photometric detector quantification of organosulphur compounds requires careful optimization of the gas chromatograph parameters. Although the relative response of the flame photometric detector to various sulphur compounds remains somewhat controversial [7], analysis of organosulphur compounds by flame photometric detector is now relatively straightforward. 

The chromatographic parameters discussed above were calculated for packed beds (increased dispersion and bed length), and for expanded beds with moderate, higher and lower dispersion. The results indicated that the corresponding separation parameters of packed beds and expanded beds are commensurable, therefore, expanded beds can be successfully employed in liquid chromatography even in the case of trace analysis of synthetic dyes in waste water and sludge [75],... 

The same chromatographic parameters were used in determining the molar response of the individual PCB isomers except, that the area responses were determined with a flame ionization detector. The flow rates of the hydrogen and air combustion gases were 30 and 300 mL/min, respectively. Response factors needed to... 

Module 6, Column Diagnosis (COLDIAG). This module uses chromatographic parameters such as efficiency, asymmetry, retention time, selectivity and operating pressure, to detect failures of the column or other chromatographic hardware. Table II lists the types of column failure which the module can currently handle. Note that the module will also correctly diagnose some problems which are NOT column malfunctions but which might be interpreted as such by a user. 

In addition, the HP ChemStation provides password protection against accidental data loss or methods changes. The HP ChemStation controls and monitors all GC parameters and maintains a logbook of all system events that occur while the GC system is running. System-suitabihty software, which allows analysts to select from a wide variety of chromatographic parameters to monitor and verify system performance, is also available. 

The important chromatographic parameter, which can directly be Obtained from the chromatogram, is the retention fiactor k. It is given by the ratio of mass of eluite bound to the stationary phase to the mass in the mobile phase and is conveniently expressed by the corresponding equilibrium concentrations and the phase ratio, When a complex formation in the mobile phase dominates, i.e., the chromatographic process can be represented by the first limiting case, the retention fiactor is obtained by combining Eqs. (SI), (65), (66), and (68) to obtain... 

A number of kinetic models of various degree of complexity have been used in chromatography. In linear chromatography, all these models have an analytical solution in the Laplace domain. The Laplace-domain solution makes rather simple the calculation of the moments of chromatographic peaks thus, the retention time, the peak width, its number of theoretical plates, the peak asymmetry, and other chromatographic parameters of interest can be calculated using algebraic expressions. The direct, analytical inverse Laplace transform of the solution of these models usually can only be calculated after substantial simplifications. Numerically, however, the peak profile can simply be calculated from the analytical solution in the Laplace domain. 

The elution factors in normal-phase TLC and RP-HPLC, using a fixed set of chromatographic parameters, were determined for a series of saturated triacylglycerides with TCN from C30 to Ceo, serving as reference compounds and various oxidation derivatives of analogous unsaturated triglycerides, including hydroperoxides, peroxides, epoxides, core aldehydes and their DNP derivatives. From these measurements, a series of incremental... 

Basic Considerations Linking Retention, Resolution, and Peak Efficiency with the Other Chromatographic Parameters... 

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