LC-MS/MS using electrospray ionization (ESI) is a widely used platform for routine target analysis and quantitation. However, one big challenge faced through the use of ESI is the presence of matrix effects. So, what are matrix effects and why are…
If excessive force is applied at an angle to a fitting or column connector, the ferrule could become stuck in the column end fitting. Likewise, a PEEK connector, column nut or plug can also break and leave part of it…
My colleague, Joe Konschnik and I have been asked by many food chemists out there about how much they can trust their pesticides mixes after they combine them into one single larger mixture for calibrating their instrument, or monitoring the…
Analysis of PFAS (per- and polyfluorinated alkyl substances) has been a hot topic for envoironmental labs for the last several years. Currently there are two C8 based PFAS compounds (PFOA and PFOS) with a health advisory level of 70 ppt…
One of the most common questions I am asked by customers is “Why is my peak shape so poor?” Another is “I do not see a peak for my compound, what should I do?” Sometimes they are developing a new…
Bile acids are a group of steroidal acids with carboxyl and hydroxyl groups on the side. They are the major metabolic products of cholesterol. Bile acids play important roles as biomarkers for early diagnosis and therapeutic monitoring of many diseases,…
My first blog here at Restek was a demonstration of how increasing the source temperature could improve the raw response of 2,4-dinitrophenol while maintaining the relative response. Four years later I’m here with the promised follow-up on the elevated source…
Recently one of the designers of the Super-Clean Gas Filters spent some time with technical service and we were able to ask him a few common questions we get asked by customers. I thought I would share this information with…
Recently I came across a situation where I wanted to make a series of constant flow GC-FID runs, during which, the inlet pressure would increase from 2 to 6 PSI over the temperature program. I also wanted to use split…
Peak Capacity in capillary gas chromatography is different than sample loading capacity, which is something I’ve posted on multiple times recently in ChromaBLOGraphy. Peak capacity is simply the number of theoretical peaks that can “fit” inside a chromatogram under some…
