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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Resolving Weak Retention and Multiple Interferences in the HPLC Analysis of Sodium Metabisulfite
by Shu Cheng
October 12, 2025

This article discusses an HPLC method for accurately determining sodium metabisulfite in complex formulations where common additives such as citric acid, sodium benzoate, and disodium EDTA may cause interference. By using Welch Xtimate Sugar-H column, the method achieves strong retention and effective separation without interferences.

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The Savior of Diabetes: Human Insulin and Its HPLC Analysis Method
by Gary Lee
October 10, 2025

This article presents an HPLC case study on the analysis of human insulin using the Welch Xtimate® SEC-120 column, featuring the column’s stable and reliable performance in quantifying human insulin injections.

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A Premier Alkaloid: Nicotine and the Strategy for Developing Its Determination Method
by Gary Lee
October 9, 2025

Nicotine analysis is notoriously challenging due to its weak retention on conventional columns. This article shares a practical UHPLC-MS method using the Welch Ultisil HILIC Amphion II column, detailing the development approach, chromatographic conditions, and key advantages for reliable nicotine detection.

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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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Determination of Mannitol Related Substances with Xtimate Sugar-Ca
by Shu Cheng
September 19, 2025

Mannitol is a substance with important applications in pharmaceutical and food. See how Welch Xtimate Sugar-Ca columns perform well in determination of mannitol related substances in accordance with Chinese Pharmacopoeia 2025 Edition.

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Column Substitution in HPLC: More Than Just Matching Specs
by Shu Cheng
September 11, 2025

When considering HPLC column replacements, cross-reference charts can only tell half the story. Read to learn how a right Welch Column goes beyond replacement—delivering optimized results tailored to your method.

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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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