Stepwise gradient optimization

This stepwise gradient optimization procedure was evaluated for the HPTLC separation of a mixture of seven compounds. The experimental data and predicted results using the optimum condition compositions were in good agreement. 

Optimization, 81-99 general methods of, 81-92 mixture design statistical technique, 88-91 multifactor optimization system, 91-92 the PRISMA method, 86-88 simplex optimization, 83-86,87 window diagrams, 81-83 miscellaneous methods of, 92-97 stepwise gradient optimization, 95-96 two-dimension optimization, 92-95,96 unknown component optimization, 97 of the mobile phase, 23-25 Organochlorine (OC) insecticides color reactions of, 805... 

Soczewihski, E. Stepwise gradient development in thin-layer chromatography. Optimization of gradient program. J. Chromatogr. 1986, 369, 11-17. 

Wang, Q.-S. Yan, B.-W. Zhang, Z.-C. Computer-assisted optimization of mobile phase composition in stepwise gradient HPTLC. J. Planar Chromatogr. 1994, 7, 229-232. 

Matysik, G. Markowski, W. Soczewihski, E. Polak, B. Computer-aided optimization of stepwise gradient profiles in thin-layer chromatography. Chromatographia 1992, 34, 303-307. 

Golkiewicz, W. (1981b). TLC as a pilot technique for optimization of gradient HPLC. 1. Experimental verification of a graphical method for the optimization of stepwise gradient elution. Chromatographia 14 411-414. 

Matysik, G., and Soczewinski, E. (1996). Computer-aided optimization of stepwise gradient TLC of plant extracts. J. Planar Chromatogr.—Mod. TLC 9 404-412. Matyska, M., and Soczewinski, E. (1993). Optimization of chromatographic systems in TLC by graphical method and with a computer program. Chem. Anal. (Warsaw) 38 555-563. 

Soczewinski, E., and Swieboda, R. (1995). Computer-aided optimization of stepwise gradient thin layer chromatography. Acta Chromatogr. 5 25-33. 

A computer progam is given for the simulation of stepwise gradient TLC [49], and an optimization preparative separation has been reported [50]. 

IV. OPTIMIZATION OF STEPWISE GRADIENT ELUTION A. Graphical Method... 

Multiple development techniques using stepwise solvent gradients enable a subset of optimal separation conditions to be used to separate a mixture of wide polarity that cannot be separated using a single mobile phase (117,119,120,125). As an example of this approach the separation of 20 common protein amino acid PTH-derivatives is shorn in Figure 7.12 (126). Five... 

Amino acids are separated in their native form on a sulphonated polystyrene resin using a system of sodium or lithium based buffers. Separation is effected by stepwise, rather than gradient elution, and the chromatography can be further optimized by carefully controlling the temperature of the analytical column. 

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