Separation optimizing using computer software

J. E. Madden, M. J. Shaw, G. W. Dicinoski, and P. R. Haddad, Simulation and Optimization of Retention in Ion Chromatography Using Virtual Column 2 Software, Anal. Chem. 2002, 74, 6023 P. R. Haddad, M. J. Shaw, J. E. Madden, and G. W. Dicinoski, Computer-Based Undergraduate Exercise Using Internet-Accessible Simulation Software for the Study of Retention Behavior and Optimization of Separation Conditions in Ion Chromatography, J. Chem. Ed. 2004, 81, 1293 http //www.virtualcolumn.com. 

Automation allows batch chromatography to be run as a continuous process. Multiple injections using a separate pump and fraction collection provide an opportunity for continuous unattended operation. In iso-cratic separations, sample injection is often made before previously injected product elutes from the column, thus reducing cycle time and solvent consumption. Continuous and automated processes are always used with smaller columns and lower amounts of expensive enantioselective stationary phases. One of the future goals for modern PHPLC optimization would be the creation of software that would allow computer simulation modeling of nonlinear effects in preparative chromatography. 

Dipole Moment The dipole moment of a molecule is the first moment of the electric charge density expansion. All normal paraffins have a value of zero. Charge separation within the molecule due to electronegativity differences between bonded atoms increases the dipole moment. Computational chemistry software uses the electron density distribution of the optimized molecule to calculate dipole moments. 

In addition, even if peak area measurements are used, a separation of 4a will usually provide adequate accuracy and this is particularly so if computer data acquisition and processing is used with peak deconvolution software. In general, a resolution of 4a will be assumed whenever dealing with resolution or column design. In most column optimization procedures the effect of increasing the criteria for resolution can easily be accommodated if so desired. 

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