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Knowledge Base

[Readers Insight] Choose Methanol or Acetonitrile? The Organic Mobile Phase in HPLC

November 17, 2025

In HPLC analysis, methanol and acetonitrile are the most common organic mobile phases. But have you ever thought about what exactly differentiates them? When should methanol be used and when acetonitrile? In this article, the author shares their thoughts on this matter.

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Understanding HPLC Pumps (Part II): Practical Maintenance

November 13, 2025

In the second part of this article, we explain the composition of an HPLC pump and the terminologies behind, as well as practical troubleshooting and preventive maintenance methods and schedules to pump failures.

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Understanding HPLC Pumps (Part I): Common Misconceptions

November 13, 2025

In the first part of this article, we explain common misconceptions of HPLC pumps, from the number of pump channels (and why they don't equal the number of pump heads or modules) to the differences between high- and low-pressure systems, and parallel and serial pumps.

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[Readers Insight] Why Do Substances with Similar Polarity Dissolve in Each Other?

November 12, 2025

In this article and attached video, the author discusses why substances with similar polarity dissolve in each other through dipole-dipole interactions, the energy change during dissolution, and the effect from entropy and Gibbs free energy.

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[Readers Insight] HPLC Column Selection: Core to Method Development (Part II)

November 6, 2025

In this article, the author shares their answers for 8 common questions in column selection, aiming to guide users in choosing the most suitable column through practical experimentation.

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[Readers Insight] HPLC Column Selection: Core to Method Development (Part I)

November 5, 2025

A chromatographic column is the heart of separation. However, with thousands of column options on the market, it is often asked how to choose "the best one". In this article, the author explains the classifications of HPLC columns and how to select the most cmpatible column for an analyte.

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[Readers Insight] Why Do Ghost Peaks Appear?

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?

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

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

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?

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

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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