The Chromatography and Sample Preparation Terminology Guide (PDF)
This terminology guide covers liquid chromatography (LC), Gas Chromatography (GC), and sample preparation.
(Link to ThermoFisher Scientific website)
Importance of Inert GC Pathways
When measuring trace-level impurities, your GC system needs to be optimized and inert. If it is not, low-level compounds cannot be adequately distinguished from the baseline and accurate identification and quantification become difficult or impossible. Sensitivity is strongly influenced by column factors including inertness and bleed.
Carrier Gases: Hydrogen as an Alternative to Helium
As the Helium shortage continues to grow, Helium prices are rocketing sky high and in some cases companies are being told they can not get any. Switching to Hydrogen as a carrier gas offers some great advantages.
The Impact of Using Guard Columns in Gas Chromatography (PDF)
Most of the time, impurities accumulate in the first meter(s) of the column. As the separation process in the capillary starts here, the unwanted interactions that take place will immediately impact the initial band width. Many users choose to connect guard columns in front of the analytical column to protect the analytical column from contamination. These guard columns are deactivated and can be trimmed when polluted and eventually replaced.
GC Capillary Columns 101 (Infographic)
Phase polarity, film thickness, inner diameter, length — the choices you make for common GC capillary column specifications can affect your chromatography in so many ways.
GC Inlet Maintenance Guide (PDF)
Liners, septa, inlet seals... when compared to your analytical column, your instrument, or a customer lost due to missed deadlines or inaccurate data, these small consumables carry an almost nonexistent price. And yet, the impact they can have on your analysis — not to mention your livelihood is huge: breakdown of active compounds, loss in response, and other performance issues. In extreme cases, improperly selected or poorly maintained inlet supplies can mean the difference between detecting your compounds or not.
Choosing the Right HPLC Column (PDF)
Follow our HPLC column selection flow chart as a starting point for your method development.
Developing HPLC Methods for Speed and Longevity
Our top recommendations for developing a swift, trouble-free method that can easily be transfered.
How to Improve HPLC Peak Shape by Optimizing Your Injection (Video on Restek Website)
Injection volume and solvent choice are among the many factors that contribute to good liquid chromatography. If we inject too much, we can drastically degrade peak shape by causing our peaks to front. At the same time, we want to choose an injection solvent that matches our initial mobile phase conditions. Note that between 33 seconds and 1 minute through the video, the presenter discusses injection volume relative to column volume. In this video column volume refers to the column void volume. This is approximately 67% of the geometric volume of the empty column hardware when using fully porous particles ( π r² h) or 50% of the empty column volume for superficially porous particles.
Sample Preparation Handbook (PDF)
This handbook includes an overview of sample preparation techniques, industry-specific examples of challenging analyses, product information, and many cost saving tips and tricks.
Solid Phase Extraction (SPE)
SPE is a broad term to describe the digital (step wise) separation technique where liquids contact sorbents, and organic compounds or ions in the liquid adsorb to the functional group(s) of the sorbent.
QuEChERS (pronounced Catchers), is an acronym for Quick, Easy, Cheap, Effective, Rugged and Safe. The process is a sample extraction and clean-up technique widely used for the analysis of multiple residues in food, forensic and environmental samples.
Soxhlet Extraction is the most widely used method for the extraction of solids. It is effective when your analytes have limited solubility and the sample impurity is insoluble in the desired solvent.
Derivatization reagents are designed to simplify chromatography by increasing sample volatility, allowing for simple GC-FID detection.