Waters 484 detector

The HPLC apparatus used for analytical enantioseparations consisted of a PerkinElmer (Norwalk, CT, USA) 200 LC pump equipped with a Rheodyne (Cotati, CA, USA) injector, a 50 μL sample loop, an HPLC PerkinElmer oven and a PerkinElmer detector. The signal was acquired and processed by Clarity software (DataApex, Prague, Czech Republic).
In analytical separations, fresh standard solutions of carvedilol were prepared shortly before using by dissolving 1–3 mg of analyte in 20 mL of ethanol. The injection volume was 20 μL.
For semipreparative separation, a PerkinElmer 200 LC pump equipped with a Rheodyne injector, a 5000 μL sample loop, a PerkinElmer LC 101 oven and Waters 484 detector (Waters Corporation, Milford, MA, USA) was used. The feed solution for milligram enantioseparations was prepared by dissolving 49.35 mg of racemic carvedilol in 4 mL of ethyl acetate and diluting the solution with 4 mL of the mixture n-hexane-IPA-EA-DEA 50:30:20:0.1 (v/v/v/v).
The polarimetric analysis of the enantiomers of carvedilol collected on a semipreparative scale was carried out measuring the specific rotations at five wavelengths by a PerkinElmer polarimeter model 241 equipped with Na/Hg lamps. The volume of the cell was 1 mL and the optical path was 10 cm. The system was set at a temperature of 20 °C.

The HPLC apparatus consisted of a Dionex P580 LPG pump, an ASI-100 T autosampler, an STH 585 column oven, a PDA-100 UV detector or a Jasco (Tokyo, Japan) Model CD 2095 Plus UV/CD detector; data were acquired and processed by a Chromeleon Datasystem (Dionex Corporation, Sunnyvale, CA). For semipreparative separation, a Perkin-Elmer (Norwalk, CT, USA) 200 LC pump equipped with a Rheodyne (Cotati, CA, USA) injector, a 5000 μL sample loop, a Perkin-Elmer LC 101 oven and Waters 484 detector (Waters Corporation, Milford, MA, USA) was used. The signal was acquired and processed by Clarity software (DataApex, Prague, The Czech Republic).
In analytical separations, fresh standard solution of OME and single impurities were prepared shortly before using by dissolving 1–3 mg of each analyte in the mobile phase.
In order to ensure reproducible chromatographic performance, after the incorporation of acid or basic additives into the mobile phase, the IG-3 column was washed with the following mobile phases: ethanol at 0.5 mL/min for 30 min, followed by tetrahydrofuran at 0.5 mL/min for 120 min and, finally, ethanol at 0.05 mL/min for 120 min.