Visualizing small differences using subtractive chromatographic analysis.
Subtraction of chromatograms coming from two different samples collected under identical conditions can highlight small variations, serving as a useful tool for visualizing differences between experimental and control groups. While the basis for this general approach has been known for decades, the technique is seldom used in modern chromatographic analysis. We report an investigation into the application of subtractive chromatographic analysis in several areas of pharmaceutical research where detection of small differences between samples is important. Our investigation found that elimination of artifacts caused by peak misalignment was often necessary, especially for extremely sharp chromatographic peaks obtained in rapid injection MISER chromatography. Alignment of individual peaks prior to subtraction, combined with fast detector sampling rates, or data interpolation in cases where this is not possible, was found to afford convenient visualization of small differences (∼1%) among samples, suggesting potential utility in high throughput screening of process adsorbents or other applications in pharmaceutical research and development.
Department of Process Research & Development, Merck Research Laboratories, Rahway, NJ, USA. Electronic address: kerstin.zawatzky@merck.com.
Kerstin
K
Zawatzky
Department of Process Research & Development, Merck Research Laboratories, Rahway, NJ, USA.
Mikhail
M
Reibarkh
Department of Pharmaceutical Sciences & Clinical Supply, Merck Research Laboratories, Rahway, NJ, USA.
Nicole
N
Canfield
Department of Early Development Programming, Merck Research Laboratories, Rahway, NJ, USA.
Ting-Chuan
TC
Wang
Department of Chemistry, University of Nebraska-Lincoln, Lincoln, NE, USA.
Shanren
S
Li
Department of Chemistry, University of Nebraska-Lincoln, Lincoln, NE, USA.
Liangcheng
L
Du
Department of Process Research & Development, Merck Research Laboratories, Rahway, NJ, USA. Electronic address: christopher_welch@merck.com.
Christopher J
CJ
Welch
D000465:Algorithms; D016477:Artifacts; D002626:Chemistry, Pharmaceutical; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D003470:Culture Media / Q000737:chemistry; D053528:Lysobacter / Q000737:chemistry / Q000235:genetics; D008751:Methylene Blue / Q000302:isolation & purification; D009288:Naproxen / Q000737:chemistry; D013237:Stereoisomerism
D003470:Culture Media; D009288:Naproxen; D008751:Methylene Blue
High throughput analysis; Multiple injections in a single experimental run; Peak alignment; Subtractive chromatography