Richard S. Egan
Merck & Co.
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Publication
Featured researches published by Richard S. Egan.
Journal of Pharmaceutical and Biomedical Analysis | 2000
Tiebang Wang; Jane Wu; Robert Hartman; Xiujuan Jia; Richard S. Egan
A multi-element inductively coupled plasma-mass spectrometry (ICP-MS) survey method has been demonstrated as an alternative to the antiquated heavy metals limit test prescribed by United States Pharmacopoeia (USP), European Pharmacopoeia (EP), and British Pharmacopoeia (BP), for drug substances, intermediates, and raw materials. The survey method is simple, fast, sensitive, semi-quantitative to quantitative, and includes all the elements which can be analyzed by atomic spectroscopy.
Journal of Pharmaceutical and Biomedical Analysis | 1997
Tao Wang; Sheila Walden; Richard S. Egan
A simple, selective, sensitive, accurate and relatively inexpensive method for the determination of palladium in bulk pharmaceutical chemicals (BPC) and their synthetic intermediates by graphite furnace atomic absorption spectroscopy has been developed and validated. Sample preparation by direct dissolution of sample in 70% nitric acid is simple and effective without adverse effects. The limit of detection and the limit of quantitation of the method were determined to be 0.7 ppm and 2 ppm respectively in BPC.
SPIE's 1992 Symposium on Process Control and Monitoring | 1992
Jhansi R. Boaz; Scott M. Thomas; Steven M. Meyerhoffer; Steven J. Staskiewicz; Joseph E. Lynch; Richard S. Egan; Dean Ellison
We have developed an FT-IR method, using a Spectra-Tech Monit-IR 400 systems, to monitor off-line the completion of a reaction in real-time. The reaction is moisture-sensitive and analysis by more conventional methods (normal-phase HPLC) is difficult to reproduce. The FT-IR method is based on the shift of a diazo band when a conjugated beta-diketone is transformed into a silyl enol ether during the reaction. The reaction mixture is examined directly by IR and does not require sample workup. Data acquisition time is less than one minute. The method has been validated for specificity, precision and accuracy. The results obtained by the FT-IR method for known mixtures and in-process samples compare favorably with those from a normal-phase HPLC method.
ChemInform | 1974
Richard S. Egan; Leslie A. Freiberg; William H. Washburn
The Journal of Antibiotics | 1974
Jerry R. Martin; Richard S. Egan; Alma W. Goldstein; Sandra L. Mueller; Esther A. Hirner; Ruth S. Stanaszek
Journal of Agricultural and Food Chemistry | 1997
John M. Ballard; Lori D. Payne; Richard S. Egan; Teresa A. Wehner; Gregory S. Rahn; Samson Tom
The Journal of Antibiotics | 1994
Francis P. Gailliot; Theresa K. Natishan; John M. Ballard; Robert A. Reamer; Dennis Kuczynski; Gregory J. Mcmanemin; Richard S. Egan; Barry C. Buckland
The Journal of Antibiotics | 1974
Richard S. Egan; Sandra L. Mueller; L. A. Mitscher; Isao Kawamoto; Ryo Okachi; Hiromasa Kato; Shigeru Yamamoto; Seigo Takasawa; Takashi Nara
ChemInform | 1974
Thomas J. Perun; Jerry R. Martin; Richard S. Egan
The Journal of Antibiotics | 1974
Richard S. Egan; Sandra L. Mueller; L. A. Mitscher; Isao Kawamoto; Ryo Okachi; Kato H; Shigeru Yamamoto; Seigo Takasawa