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Knowledge Base

[Readers Insight] Why Do Ghost Peaks Appear?
by Shu Cheng
October 31, 2025

In this article, we examine the common origins of ghost peaks in HPLC. From mobile phase contamination and instrument residues, to column impurities and sample-related degradation, the article explains how they contribute to the appearance of ghost peaks.

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[Readers Insight] Is Retention Time Determined Solely by the Polarity of a Compound?
by Shu Cheng
October 27, 2025

Have you ever thought about this question: In reversed-phase chromatography, does an earlier elution always mean the compound has higher polarity? Or rather — is retention time determined solely by the polarity of a compound? In this article, we explore what polarity is, why it acts as the primary factor affecting retention time, and what other factors are unneglectable.

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[Readers Insight] Mobile Phase Selection in Method Development: How to Optimize
by Shu Cheng
October 21, 2025

In method development, the selection of mobile phases is an important part to success. This article discusses thoroughly different mobile phases and their use in HPLC and LC-MS, and provides recommendations for initial mobile phase choices.

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Common Problems in Solid-Phase Extraction: A Practical Troubleshooting Guide
by Shu Cheng
October 17, 2025

Solid-Phase Extrtaction is a fast, easy and high-performance sample preparation technique widely used, but routine SPE runs can encounter recurring problems. This article summarizes typical causes and practical fixes for each SPE problem.

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[Readers Insight] Retention Time Drifts: Why Do They Occur?
by Shu Cheng
October 17, 2025

Learn the causes of retention time drift in HPLC analyses, explained thoroughly through mobile phase, column, instrument, and sample solvent.

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[Readers Insight] Matrix Effects in Mass Spectrometry: Why They Matter
by Shu Cheng
September 22, 2025

In this article, we explore further how matrix effects affects recovery results in mass spectrometry analyses by hindering preparation loss, and discuss when it should be corrected by using calibration curves prepared by blank matrices.

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[Reader Insights] Acidic or Basic? Read Analyte Structure First When Developing a Method
by Shu Cheng
September 11, 2025

In this article, we discuss how to read molecular structure to assess an analyte’s acidic or basic character and use that insight to design starting chromatographic methods. You will find practical, rule-based criteria, clear decision points for method setup, and a focused real-world example that illustrates structure-driven choices.

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[Readers Insight] The Starting Point in Method Development
by Shu Cheng
August 24, 2025

Method development often begins with uncertainty—especially when faced with unknown compounds and no literature guidance. This article examines a pharmacopoeial method as a case study, highlighting its chromatographic settings, analyzing potential limitations, and considering improvements. Through this, readers gain insight into the logical framework behind choosing starting conditions.

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[Readers Insight] Are You Choosing the Right Quantifier Ion for Mass Spectrometry?
by Shu Cheng
August 20, 2025

In this article, the author discusses the principles behind selecting quantifier ions in triple quadrupole mass spectrometry, with a case study to illustrate how ion choice impacts sensitivity and accuracy.

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[Readers Insight] Why Do M-Shaped Peaks Occur?
by Shu Cheng
August 14, 2025

M-shaped peaks can puzzle even experienced chromatographers, appearing unexpectedly and resisting simple fixes. This article draws on expert insights to explore their possible origins and practical approaches, guiding analysts toward more reliable and consistent chromatographic results.

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Agarose: A Versatile Packing Material for Protein Purification
by Shu Cheng
August 5, 2025

Agarose-based chromatographic media offer a compelling blend of biocompatibility, versatility, and affordability. By mastering the principles of agarose microsphere preparation and crosslinking, chromatographers can tailor supports to a vast array of protein purification challenges, ensuring high yield, purity, and process robustness.

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Mastering Gas Chromatography in 7 Comprehensive Steps!
by Shu Cheng
July 28, 2025

This article guides analysts in GC analyses through efficient sample preparation, instrument configuration, initial condition setup, separation optimization, qualitative identification using retention indices or GC–MS, quantitative analysis via internal standards or standard addition, rigorous method validation, ensuring accurate, precise, reproducible results across diverse unknown sample analyses consistently.

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