When would I choose SLE? When would I choose SPE? We all have faced those questions. Let's have a look at the two sample preparation techniques. 

You've just decided to develop a solid phase extraction (SPE) method for a new assay in your lab. However, there are so many decisions to be made! Which company to choose? Which product to use? Polymer based sorbent or silica based? Cation or anion exchange? While this seems incredibly difficult, it doesn't have to be that hard!

If you are frustrated with low recoveries caused by protein binding during Supported Liquid Extraction (SLE) and Solid Phase Extraction (SPE), this blog post will give you a few tips. Proper sample pre-treatment is the key to solving this issue.

Solid-phase extractions (SPE) can be a long and sometimes complicated process. So, we want to make sure that everything works the first time we extract. In this blog post, I will be discussing some of the benefits that we see when using positive pressure for SPE.

There is often confusion as to how to choose the proper SPE ion exchange media. How do you determine if you should be looking at anion or cation, weak or strong? In this post, I will give some simple guidelines on making the best choice. You will see that ion exchange is all about acids and bases.

When it comes to sample cleanup the question occasionally comes up asking what technique is best for my application: Solid Phase Extraction (SPE) or Supported Liquid Extraction (SLE)? Well, what’s right for you depends on your application and the characteristics of your analytes. This post outlines some of the advantages, disadvantages and limitations of each technique.

What is a weak ion exchange SPE phase? What is their charge state and how they behave in function of pH conditions? When to choose them? This post will describe Biotage mixed mode weak ion exchange SPE phases - EVOLUTE EXPRESS WCX and EVOLUTE EXPRESS WAX - and how to optimize your sample preparation of your analytes of interest.

Mixed mode Solid Phase Extraction (SPE) phases have become very popular for sample clean-up prior to analysis using mass spectrometry. Having the capability to retain compounds by two modes of interaction during SPE is useful when a large number of analytes with different properties are of interest.

How the acid dissociation constant (pKa) affects sample preparation method development? Knowing and understanding the pKa of your compounds tells you if the compound can be ionized, and under what conditions, so you can use this property to develop better sample prep methods.

Understanding the chemical properties of the compounds in your sample matrix, both the ones you want to detect and the ones you want to eliminate, is necessary for successful method development. Is the molecule acidic or basic? What functional groups are present and can they be ionized? Is the molecule hydrophilic or hydrophobic? In this post, we discuss logP, and its role in sample preparation.