A gradient elution
program was applied for chromatographic analysis (Table 1).
In the findings of a published study by Geng in the Journal of Science China Chemistry on the two variable-theory of peptides under gradient elution
in 2017, a dynamic separation method for the rapid identification and improvement of the selectivity of peptides achieved by simply changing the mobile phase flow-rate (MPF-R).
Since CAD response is known to be affected by mobile phase composition, an inverse gradient compensation was implemented to assess the ability for uniform response across a typical drug gradient elution
. This turned out to be an important addition for CAD response, as results without gradient compensation demonstrated an underestimation of compounds prior to active pharmaceutical ingredient (API) detection and an overestimation of compounds after the API due to the changing organic composition within a gradient.
Initially, a gradient run from 2% to 92% was achieved to determine whether isocratic or gradient elution
was appropriate .
speciosum extract from three different batches was performed using a rapid high-performance liquid chromatography method under the conditions using gradient elution
with a mobile phase of acetonitrile-water, as previous described by our group .
The water (containing 0.1% formic acid and solvent A) and acetonitrile (solvent B) was used as mobile phase with gradient elution
. The gradient was as follows: 0 min 5% B, 0.5 min 5% B, 2.0 min 80% B, 2.1 min 5% B, and 3.0 min 5% B, and then stopped.
The four synthetic food dyes are efficiently separated using an optimized gradient elution
in a single run within 15.1 min.
was performed with (A) 80% methanol and (B) 20% water (pH 3.5 modified by o-phosphoric acid) at flow rate of 1.0 mL min-1 after filtration through 0.45 um pore size.
The fractionation of the ethyl acetate extract was done through a series of gradient elution
normal phase gravity column chromatography (GCC) on a 60 - 230 mesh silica gel stationary phase .
Recommendations are made concerning initial column selection and the choice of isocratic or gradient elution
The separation was performed on ODS-C18 column (100 x 4.6 mm, 3 [micro]m) with gradient elution
by the mobile phase A, methanol-0.1% formic acid (10 : 90), and mobile phase B, methanol-acetonitrile-0.1% formic acid (50:30:20); the gradient elution
processes is 0min (0% B), 15 min (8% B), 45 min (30% B), 60 min (35% B), and 75 min (100% B); the flow rate was 1.0mL/min; the column temperature was 40[degrees]C; and the detection wave length was set at 280 nm.
The described method of the prediction of retention time can substantially reduce the time required to find optimal conditions in gradient elution