Securityguard hplc cartridge system

In this study, we used a Shimadzu HPLC system (Shimadzu Co., Kyoto, Japan) equipped with a fluorescence detector (RF-20A), column oven (CTO-20A), autosampler (SIL-20AC), and pump (LC-20AT). A Kinetex C18 column (250 × 4.6 mm, 5 μm, 100 Å; Phenomenex, Torrance, CA, USA) protected by a C18 guard column (SecurityGuard HPLC Cartridge System; Phenomenex) at 40 °C was used for chromatographic separation. Isocratic elution of mobile phase consisting of 10 mM phosphate buffer (pH 6.0) and ACN (53.6:46.4, v/v) was performed at a flow rate of 1 mL/min. The injection volume and total run time were 20 μL and 23 min, respectively. The fluorescence excitation and emission wavelengths for REP, CEL, and IS were 240 and 380 nm, respectively.

A Shimadzu HPLC system combined with fluorescence detector (Shimadzu Co., Kyoto, Japan) was used in this study. Chromatographic separation was conducted at 40 °C using a Kinetex C8 column (250 × 4.6 mm, 5 μm, 100 Å; Phenomenex, Torrance, CA, USA) protected by a C8 guard column (SecurityGuard HPLC Cartridge System, Phenomenex, Torrance, CA, USA). The gradient elution of the mobile phase consisting of pH 6.0 10 mM potassium phosphate buffer (Solvent A) and ACN (Solvent B) was performed at a flow rate of 1 mL/min as follows (solvent A:solvent B, v/v): maintained at 58:42 for 12.5 min; ramped from 58:42 to 50:50 for 0.5 min; maintained at 50:50 for 9 min; back to 58:42 for 0.5 min; and maintained for 3.5 min (total run time: 26 min).

A Shimadzu HPLC-UV system with a pump (LC-20AT), an autosampler (SIL-20AC), a column oven (CTO-20A), and an ultraviolet detector (SPD-20A) was used in this study (Shimadzu Co., Kyoto, Japan). A Kinetex C18 column (250 × 4.6 mm, 5 μm, 100 Å; Phenomenex, Torrance, CA, USA) protected by a C18 guard column (SecurityGuard HPLC Cartridge System, Phenomenex) was used for chromatographic separation at 40 °C. The mobile phase for the HPLC system consisted of phosphate buffer (pH 5.0; 10 mM) (solvent A) and ACN (solvent B) at a flow rate of 1 mL/min. The gradient elution protocol was as follows (solvent A/solvent B (v/v)): ramped from 71:29 (v/v) to 59:41 (v/v) during 10 min; back to 71:29 (v/v) for 10 min. The wavelength for SBN and IS was set as 220 nm. The total run time and injection volume were 20 min and 20 μL, respectively. All solvents used for sample preparation and HPLC analysis were degassed by sonication under vacuum and in-line electronic vacuum degasser modules.