Spherical coordinate representations of solvent composition for liquid chromatography method development using experimental design

Applications of mixture experiments for response surface methodology implementation in analytical methods development

“…16,20,21,34 Others strategies that use spherical coordinate approaches have been used to optimize mixture and process factors by transforming mixture factors into independent variables parameters. 27,38…”

“…In addition, process (independent) and mixture (dependent) factors were also simultaneously optimized 16,20,21,34 . Others strategies that use spherical coordinate approaches have been used to optimize mixture and process factors by transforming mixture factors into independent variables parameters 27,38 …”

Recent Advances in the Analysis of Steroid Hormones and Related Drugs

“…Although the principles and practice of mobile phase optimization in HPLC were already set up in the early period of the history of HPLC, further studies are time to time made refining of the optimization with steroids and other compounds as the models. These include the description of a general quantitative relationship for column selectivity in RP-HPLC and the study of the effect of the change in conditions, 177 the use of experimental design for spherical coordinate representations of solvent composition in RP-HPLC, 178 prediction of the RP-HPLC retention of steroids using solvatochromic parameters, 179 the use of 2 3 factorial design and computer simulation, 180 triangle optimization for the separation of finasteride and related compounds, 181 the effect of the pH of the mobile phase for the separation of ionisable steroids, 182 the effect of column overloading on the separation of mometasone furoate and clotrimazole at widely different concentrations. 183 The first example for the improvements in the selectivity of the UV detection in the HPLC analysis of steroids is the detection of co-eluting species in e.g., danazol by subtracting the up-slope and down-slope diode-array spectra from the apex spectrum.…”

Multi-segment linear gradient optimization strategy based on resolution map in HPLC

“…Computer-assisted optimization has been widely applied in different separation modes of liquid chromatography such as normal phase [13,14] , reversed phase [15,16] and ion exchange liquid chromatography [8,9,17] and various modes of elution including isocratic [3,6,16,18] , linear gradient [17,19] , stepwise gradient [15] , nonlinear gradient [16,20] and multi-segment linear gradient [21] . In most cases isocratic elution is only suitable for the analysis of samples with a narrow range of retention.…”