Gradient time, temperature and pH were selected as the factors of a full factorial design.
The organic modifier, buffer pH, gradient time and initial hold time were selected as primary parameters.
The following parameters were selected for measurements: gradient time, temperature and pH.
Other factors, in particular temperature and gradient time, can then be included in the design.
In the process of gradient optimization, gradient time, gradient procedure and initial composition of the mobile phase were taken into consideration.
Various combinations of gradient time programs were tried and then finalized wherein all impurities and degradents are well separated from the main peak due to lafutidine.
Taking gradient time, dwell time, and equilibrium time into consideration, 50-mm monolithic column has better peptide separation than 250-mm monolithic column.
Critical parameters are identified as column selection, identification of the mobile-phase composition, gradient time, temperature, pH (for ionizable compounds), and buffer concentration.
Three HPLC parameters, the buffer concentration (ammonium acetate concentration), gradient time, and temperature, were evaluated within the quality design framework, and the effects on chromatographic parameters were investigated.
Further improvement of the analysis time, with conservation of the previously optimized selectivity, was possible by reducing the gradient time and increasing the flow rate.
The initial content of methanol in the mobile phase, the gradient time, and the concentration and the pH value of the buffer were chosen as relevant experimental parameters.
