Separation Science

Understanding GPC/SEC - Finding the Right Particle Size and Pore Size

Want to understand what the correct criteria for column selection should be based on? If so, this tutorial is for you...

Understanding GPC/SEC - Unexpected Peak Shapes

Do you find weird peak shapes in your chromatograms? Not sure if they are real or artifacts?

The Power of GC Detectors

Want to know more about detectors for GC and when to use them...

Understanding GPC/SEC - How to deal with pressure problems

So you're using gel permeation chromatography (GPC) / size exclusion chromatography (SEC) but are experiencing problems with your system pressure. What do you do?

High-Precision Temperature Control for SFC Using the Agilent 1260 Infinity II Multicolumn Thermostat

Agilent Technologies has produced a Technical Overview demonstrating the use of the Agilent 1260 Infinity II Multicolumn Thermostat in the Agilent InfinityLab Supercritical Fluid Chromatography (SFC) Solution. It describes how the post column...

The Function of GC Inlets

This article will cover the general function of GC inlets and describe some common attributes, differences and provide a context for future articles covering inlets in more detail.

The Case of the Unintentional Ion-Pairing Reagent

Shifting retention times within a sample batch can be a real source of headaches in the routine HPLC laboratory. Previously we talked about the kind of retention drift experienced by some HPLC methods for the first few injections. This often is...

Why do retention times drift for the first few injections of an HPLC method?

How many of you have experienced this? You think you’ve fully equilibrated the HPLC column by running mobile phase through it for 30 min, but for the first 3 or 4 injections, the retention times drift a little, finally settling down after half a...

Does a Guard Column Make Sense?

My short answer: Yes!... and No!... and Maybe. A guard column is one of those HPLC accessories that is a bit of a mixed grill – it can be a good thing or a not-so-good thing. Let’s look at some of the different aspects of guard column use to see...

Internal Standards #2: What Makes a Good Internal Standard?

In a previous blog we took a brief look at why we might decide to use an internal standard and how a calibration plot is constructed and used in HPLC analysis. This time, we’ll consider some properties that are necessary when choosing a compound...

Internal Standards #1: How Does It Work?

In the next few blogs in this HPLC Solutions serieswe’ll look at several aspects of the use of internal standards (IS) in HPLC and LC-MS applications. The topic of this discussion is how an internal standard is used in quantitative analysis.

Column Protection #1: Filtration or Centrifugation?

It is easy to take knowledge for granted, especially when you’ve been involved in a field for a long time, as I have with HPLC. One of those areas is about how to protect the column. In the training courses we teach, Tom Jupille and I jokingly...

     

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