dRI baseline fluctuations caused by temperature programming were minimized by using a mobile phase heater to thermostat connecting tubing.
The LC analyses were carried out using a mobile phase composed of acetonitrile, 2-propanol and water, under gradient elution.
Approximately 500 milligrams of each sample was extracted into methanol, filtered, diluted 1 20, and analyzed by HPLC, using a mobile phase consisting of 0.1% formic acid in water and 0.1% formic acid in methanol.
The analytes of interest were then eluted onto an analytical column for further chromatographic separation using a mobile phase of greater solvent strength.
The chromatographic analysis was performed using a mobile phase gradient with a flow rate of 1 mL min−1 and detection wavelength of 385/528 nm (λexc/λem).
GFX and MK in plasma samples were separated using a mobile phase consisting of a mixture of ethyl acetate:methanol:25% ammonia, (8 4.5 3, v/v/v).
Gradient mode was considered using a mobile phase consisting of 0.1% (v/v) formic acid aqueous solution and acetonitrile containing 0.1% (v/v) formic acid at a flow rate of 0.45 mL/min.
Separation and quantitation were achieved with a silica column using a mobile phase consisting of methanol and water (87:13, v/v) at a flow rate of 1.0 mL/min.
using a mobile phase of 60% acetonitrile and 40% water at a flow rate of 1.0 mL/min.
The previous experiment was performed using a mobile phase consisting of acetonitrile and phosphate buffer (pH 3) at a ratio of 60 40, v/v.
Present researches indicated that better separation and results were obtained using a mobile phase of water and methanol rather than water and acetonitrile.
