Diamonsil c18 hplc column

The analysis of RPC levels in vitro and in vivo were carried out using RP-HPLC on a system equipped with an Agilent 1100 Series and a HS2000 interface (Agilent Technologies, Santa Clara, CA, USA) operated at 262 nm. The column was a Diamonsil C₁₈ HPLC column (Dikma Technologies Inc, Lake Forest, CA, USA; 5 µm, 200×4.6 mm). The mobile phase consisted of 50% PBS and 50% acetonitrile (containing 0.1% trifluoroacetic acid), and the flow rate was 1.0 mL/min. The column temperature was 30°C. A 100 µL volume of the plasma sample was transferred to a 5 mL plastic test tube together with 10 µL of internal standard solution (10 µg/mL). After vortex shaking for 1 minute, 300 µL of acetonitrile was added for precipitation. After centrifugation at 3500× g for 10 minutes, the clear supernatant was removed, and 20 µL of the sample was taken for HPLC analysis. Dexamethasone was used as internal standard in this study.

The analysis of GFT and CUR levels in vitro was carried out using LC-MS/MS on a system equipped with an Agilent 1100 Series (Agilent Technologies, Santa Clara, CA, USA) and API 2000 (AB, Massachusetts, USA). The column was a Diamonsil C18 HPLC column (Dikma Technologies Inc, Lake Forest, CA, USA; 5 μm, 200×4.6 mm). The mobile phase consisted of 20% Ammonium acetate (10 mmol/L) and 80% acetonitrile, and the flow rate was 0.2 mL/min. The column temperature was 30°C.