Archive for the ‘GCxGC’ Category

Shoot-and-Dilute GC – A Way to Keep GC Systems Up Longer to Help Lower Cost of Analyses

Dilute-and-shoot LC-MS/MS is a selective and sensitive technique often used in determining pesticides in foods.  Because of competitive ionization effects seen with electrospray (ESI) and atmospheric pressure chemical ionization (APCI) methods, quantitative accuracy suffers for trace compounds of interest when matrix coelutions occur.  Dilution of extracts (or sometimes raw samples) is a good way of […]

Analyzing pesticides in herbal tea using QuEChERS and GCxGC-TOFMS of course!

Herbal tea, a non-caffeinated drink made from plants, herbs, or spices has been used throughout history for its potential medicinal benefit.   Various herbal material is mixed depending on the desired medicinal or flavor properties for the tea.   As with any plant based commodity, there is the potential for pesticide residues to remain in the final […]

What makes your column a good High Temperature GC column?

In the last few years, the request for HT-columns (High temperature GC columns) has increased and a lot of promises have been made from different vendors. In fact, the possibility of running a GC column near or above 400°C would increase the possibilities of the GC technique quite significantly. In the petroleum industry, for example, […]

Testing for pesticides in tobacco… QuEChERS makes it easy!!

Whenever it is time to analyze pesticides in complex matrices I always hope that we can use the QuEChERS sample preparation approach and not something more laborious!  The Quick-Easy-Cheap-Effective-Rugged-Safe method was developed for multiresidue pesticides in fruits and vegetables, however we have been using this approach outside of the typical fruit and vegetable matrices with […]

Dilution and cleanup strategies for QuEChERS extracts of food prior to LC-MS/MS… and Tarballs!

If you missed the newly published tour de force piece from Julie Kowalski, check it out here: “Mitigating Matrix Effects: Examination of Dilution, QuEChERS, and Calibration Strategies for LC-MS/MS Analysis of Pesticide Residues in Diverse Food Types.” Same thing for another excellent article just published by Michelle Misselwitz, “Fingerprinting Crude Oils and Tarballs using Biomarkers and Comprehensive Two-Dimensional Gas Chromatography.” […]

Eastern Canada Trace Organic Workshop

Last month, I attended two trace environmental workshops at the National Water Research Institute (CCIW) in Burlington, Ontario; the Workshop on LC-MS/MS Applications in Environmental Analysis and Food Safety and the Eastern Canada Trace Organic Workshop (ECTOW). The full program can be found here. This was my first exposure to work done on Thermo’s Orbitrap, which […]

Dr George Frame speaks at Restek on Comprehensive Quantitative Congener Specific (CQCS) polychlorinated biphenyl (PCB) analysis

We were lucky to have Dr George Frame, PCB Analyst Emeritus as I call him, speak at Restek on the GC of PCBs prior to his plenary lecture at the International Network of Environmental Forensics meeting at The Pennsylvania State University last week.  While working as Chief of PCB Analytical R&D at GE Central Research Labs in […]

This isn’t your average CSI, the International Network of Environmental Forensics (INEF)

Next week (June 10-12) at the Pennsylvania State University (PSU) the International Network of Environmental Forensics conference is being held.  This isn’t your typical crime scene investigation but, as defined by the INEF, “environmental forensics is the use of scientific techniques to identify the source, age, and timing of a contaminant into the environment.”  We […]

No Prescription Needed: Pharmaceuticals in Your Supplements

There are many fake products out there including foods like “virgin” olive oil, honey and branded liquor. I hear a lot about these because my work focuses on food and food safety. Food fraud seems to be on the rise…at the very least governments and researchers are devoting more resources to finding and tracking incidents. […]

Mining through complex data and non-target analysis is made easier with GCxGC-TOFMS

I am currently working on a project looking for pesticides in herbal tea.  At this point, I am using the contents of one tea bag (~1.5g) and 10mL of freshly boiled water with a QuEChERS extraction.  I am still working through the details on the impact of the hot water and what type of cleanup […]