YMC-Pack Pro

Kanazawa et al. [124] determined omeprazole and its metabolites in human plasma by liquid chromatography-three-dimensional quadrupole mass spectrometry with a sonic spray ionization interface. The analytical column was YMC-Pack Pro Cig (5 cm x 2 mm) using acetonitrile-50 mM ammonium acetate (pH 7.25) (1 4) at a flow-rate of 0.2 ml/min. The drift voltage was 30 V. The sampling aperture was heated at 110 °C and shield temperature was 230 °C. In the mass spectrum, the molecular ions of omeprazole, hydroxyomeprazole, and omeprazole sulfone were clearly observed as base peaks. The method is sufficiently sensitive and accurate for pharmacokinetic studies of omeprazole. 

Fig. 1 Reaction of Ehnmb-containmg labeled peptide 14 in a TFA solution (14% CDCI3, 0.5% TCEP HC1 (v/v/w)). (a-c) NMR spectra after indicated reaction time, (d-f) RP-HPLC. Column YMC-Pack Pro C18 (4 6 x 150 nun) eluent 0.1% TFA in aq CH3CN, 1.0 mL/min...

Fig. 3 RP-HPLC profile of the crude BPTI(l-29)-SCH2CH2SO3H (33) prepared via an on-resin N-S acyl shift reaction and transthioesterification. Column YMC-Pack Pro C18 RS (4.6 X 150 mm) eluent 0.1% TFA in aq CH3CN, l.OmL/min.

Figure 10.300 Separation of streptomycin A and impurities by RPIPC with charged aerosol detection. Separator column YMC-Pack Pro,...

The fundamental reason for this phenomenon is the fact that the selectivity of a separation arises from a combination of the influence of the stationary phase and the influence of the mobile phase. If the composition of the mobile phase is drastically different from the test conditions, one can expect a different position of the different columns relative to each other. It remains correct that Symmetry Cj8 has a lower silanol activity than Spherisorb ODS-2, but whether a Lima Cjg(2) or a YMC-Pack Pro Cjg has a higher hydrophobicity or a lower silanol activity surely depends on the details of the measurement conditions. 

Figure 8.79 Separation of streptomycin suifate 20 mmoi/L pentafiuoropropionic acid/acetone and various impurities on a 3 pm YMC-Pack flow rate O mtymin detection Corona CAD Pro C18 with charged aerosol detection. Coi- injection voiume lOpL sampie 5mg/mL umn dimensions 250mmx4.6mm i.d. coi- streptomycin suifate peaks (1-16) impurities, umn temperature 40 °C eluent 99 1 (v/v) (17) streptomycin, and (18-22) impurities.

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