Archive for the ‘GC Injection Techniques’ Category

GC Inlet Liner Selection, Part IV: Liner Volume and Diameter

In parts I and II of this blog series I discussed the various liner configurations available for both split and splitless analyses.  One thing I did not mention was liner volume and inner diameter.  Most of the liners I compared are available in multiple inner diameters.  For the comparisons I did, I used a 4 […]

Want to learn about “Injection Techniques in GC” or “Practical Maintenance and Troubleshooting in GC”? Sign up to join our half day course during Pittcon, Chicago.

Please join one of our courses presented next Pittcon in Chicago: “Injection Techniques in GC”:  Monday,  March 2,  08:30-12:00, Session: SC1230. “Practical maintenance and troubleshooting in Gas Chromatography”: Tuesday, March 3, 08:30-12:00, Session: SC1231 For location, visit short course office at S100C.   Injection Techniques in Gas Chromatography In Gas chromatography the most important process […]

GC Inlet Liner Selection, Part III: Inertness

The inlet liner is the first surface analytes will interact with after introduction into a GC.  It is critical that liners are deactivated, as a number of adverse interactions can occur between analytes and the glass surface.  Deactivations typically involve some type of silanization of the surface to cover active sites inherent in glass, such […]

Amines: Topaz or Base Deactivated Liners?

Amines can be difficult to analyze by GC, since they are active and adsorb to surfaces within the chromatographic system, including the inlet liner and the column.  This leads to loss of compound response, and peak tailing.  While deactivations can help to mitigate these effects, the quality of deactivations varies.  Primary amines are especially difficult, […]

What’s in your mouse feed?

When it comes to different types of GC techniques, headspace (HS) analysis is about as clean as they come. Typically, hundreds of injections can be made without doing any inlet maintenance or column trimming. It is one of my favorite techniques in the lab since it encompasses countless different unique applications. Even though HS is […]

GC Inlet Liner Selection, Part IIB: Split Liners Continued

My colleague, Alan Sensue, asked a couple of great questions in regards to my previous blog post on split liners.  To summarize, he was interested in what happens to responses for the various liners when you change split ratios.  For instance, if you go from a 20:1 split to a 40:1 split, do detected peak […]

GC Inlet Liner Selection, Part II: Split Liners

In the previous installment of this blog series, I discussed liner selection for splitless analyses (GC Inlet Liner Selection, Part I: Splitless Liner Selection).  Today I’d like to discuss liners for split analyses.  During a split injection, the split vent is open and the majority of the flow is vented.  The split ratio, set by […]

GC Inlet Liner Selection, Part I: Splitless Liner Selection

Splitless injections are used when detection of trace amounts of analytes is necessary and the goal is to recover close to 100% of all analytes that are injected into the instrument.  During a splitless injection, the split vent is closed for a predetermined amount of time, directing all inlet flow onto the column (with the […]

GC Inlet Liner Selection: An Introduction

GC inlet liners play an important role in GC sample introduction. The sample’s first contact is with the liner and from there it is transferred to the analytical column. In the case of liquid injections, the sample must be vaporized inside of the liner prior to transfer.  Choosing a proper inlet liner for your analysis […]

3-MCPD blog part 2: How hot we can go with inlet and can we use regular split/splitless inlet?

In my last blog, I (hopefully!) made a case that switching to split injection for analysis of 3-MCPD esters is a viable option. Now I’d like to show that if we stick to split, we can also use much higher temperatures and if we can do that, we can also use regular split/splitless inlet. To […]