Archive for the ‘Tips & Tricks’ Category

One Stop Shop for Essential Oils Chromatograms

In the past few months, we have collected a variety of chromatograms using two different column phases, and three different column dimension formats. The peak identifications were performed using some standards but mostly from the NIST MS EI spectra library, 2005 edition. Let us know what you think in the comments below. Citronella Java GC_FF1296 […]

Why is my LC Retention Time Shifting?

If you have experienced retention time shifts with LC, you know it can be complicated and can cause problems with quantitation if not resolved. Hopefully this post will help you navigate through troubleshooting this situation. For the purposes of this discussion, we will be discussing changes in retention on one individual column, not differences from […]

Over tightening your fittings has consequences.

If you use the correct fittings and seals in the gas chromatography system, and follow some simple steps, there is absolutely no need to over tighten any fitting to achieve a leak free seal. For almost all fittings that use seals in a GC system, whether they are ferrules, septa or o-rings, the tightening process […]

Using a liquid leak detection solution has consequences

We have been warning about the consequences of using liquid leak detection products for years (see Blog).  These products, like Snoop, contain a whole host of compounds that can easily contaminate your GC system if you have a leak.  The solution can enter the leak site by capillary action, and is very hard to remove, […]

Discovering Analyte Breakdown On-Column

I completed my winter internship at Restek and my main task was to expand the Pro-EZGC libraries. So I created a library for Nitrosamines on the Rxi-1301Sil MS and while acquiring data we noticed a foot on a couple of my peaks. I attempted to translate the simulation to a column with the same phase, […]

Poor press-tight connections have consequences

My colleagues have written plenty of articles over the years with how to cut columns and get the perfect press-tight connection: Jaap – How to make a good fused silica seal using a Press Tight type connections Jaap – Column cutting, for making the optimal coupling Chas – How (not) to cut your capillary column […]

Analyzing avocado: How to deal with lack of water and keep the fats out

Avocados are a popular produce item. In fact, the consumption of avocados rose by 450% since 2000! The good news – avocados are ranked number 1 on the clean 15 list, meaning they have the least amount of pesticide residues. With so many avocados on the market, the testing is as important as ever, which […]

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 […]

Chiral separation on a C18 column? Separation of d- and l-amphetamines, Part II

To continue my blog part 1 (Part 1:https://blog.restek.com/?p=67087) , where I have briefly discussed the importance of separating the d and l isomers to accurately identify the illicit isomer using an achiral method on a Raptor C18 column employing a pre-column derivatization technique. Today I’d like to discuss more about the matrix of interest, sample […]