Tài liệu HPLC for Pharmaceutical Scientists 2007 (Part 8C) pdf

... The experiments for w w pH 2–4 were performed on day 1, and those for w w pH 5–7 were performed on day 2 (≈36 hr after initial prepa- ration).A further investigation was performed by preparing ... height) for peak B ≤ 1.5 • Tailing factor (5% peak height) for peak A ≤ 1.5 • Rt for peak A must be 12.0 ± 1.3 min • Rt for peak B must be 21 ± 1.0 min • The S/N of the LOQ solution (0...

Ngày tải lên: 15/12/2013, 12:15

... by the pressure limitation of the HPLC equipment. For more information on gradient separation and developing fast HPLC methods, see Chapter 17 and Practical HPLC Method Development from Synder ... 0.2- or 0.45-µm-pore-size filter is generally recommend for removal of particulates [15]. Filtration as a preventive maintenance tool for HPLC analyses is well-documented in the lit- er...

Ngày tải lên: 15/12/2013, 12:15

... down the right path for initial mobile- phase pH selection. In the following case study for this pharmaceutical compound M, the method development scenario and rationale for each iteration in ... Figure 8-40A for the sample stored in the acidic diluent for 4 days at room temperature shows some degradation compared to Figure 8-40B for the sample stored in the acidic diluent for...

Ngày tải lên: 15/12/2013, 12:15

... the basic analyte in its fully neutral form. 192 REVERSED-PHASE HPLC Step 1. First, account for the downward pK a shift for the basic analyte upon addition of organic. For every 10 v/v% increase in acetonitrile, ... Similar parameters have been determined for this family of compounds for methanol/water mixtures [80]. Using these parameters for each family of compounds for a pa...

Ngày tải lên: 24/12/2013, 18:15

... RP HPLC. We hope that it will be useful for practical chro- matographers in their efforts to develop efficient and selective separation methods, and we also hope that it will be encouraging for ... properties. For acetonitrile/water systems it was found that acetonitrile forms thick adsorbed layer on the surface of hydrophobic bonded phase, while methanol adsorption from water formed a...

Ngày tải lên: 24/12/2013, 18:15

... decreases, retention in normal-phase chromatography 241 HPLC for Pharmaceutical Scientists, Edited by Yuri Kazakevich and Rosario LoBrutto Copyright © 2007 by John Wiley & Sons, Inc. proved to be ... 5 NORMAL-PHASE HPLC Yong Liu and Anant Vailaya 5.1 INTRODUCTION High-performance liquid chromatography (HPLC) is a separation tool par excellence for the analysis of compounds .....

Ngày tải lên: 24/12/2013, 18:15

... (i.e., spanning target identification → chemical 535 HPLC for Pharmaceutical Scientists, Edited by Yuri Kazakevich and Rosario LoBrutto Copyright © 2007 by John Wiley & Sons, Inc. while maintaining ... chemist to perform high- throughput purification.Although HPLC has long been a method available to the chemist for product purification, only recently have these systems been desi...

Ngày tải lên: 22/01/2014, 00:20

... in pharmaceutical analysis. The precise and accurate control of temperature can improve repro- ducibility and method transferability (Section 18.2). In recent years, the use of 811 HPLC for Pharmaceutical ... eluent for reversed- phase high performance liquid chromatography, Anal. Commun. 33 (1996), 327–329. 57. R. M. Smith and R. J. Burgess, Superheated water as an eluent for rev...

Ngày tải lên: 22/01/2014, 00:20

... manufacturing in the pharmaceutical industry. The HPLC (or LC) and MS (LC-MS) or NMR (LC-NMR) interface increases the capability of solving 901 HPLC for Pharmaceutical Scientists, Edited by ... operation for LC-NMR (Section 20.3.2), with the use of shielded cryomagnets, the location of the MS instru- ment will follow the same rule as for the HPLC. The most common modes of ope...

Ngày tải lên: 26/01/2014, 19:20

... ions on the basis of mass-to-charge ratios, 281 HPLC for Pharmaceutical Scientists, Edited by Yuri Kazakevich and Rosario LoBrutto Copyright © 2007 by John Wiley & Sons, Inc. low-polarity ... the most widely used systems for analysis of large bio- molecules. For a continuous ion source, the ions can be stored for a short period of time and pulsed out for analysis. In the...

Ngày tải lên: 15/12/2013, 12:15