...gcxgc-column-kit ... GCxGC Selectivity Kit, 0.15 mm ... Chromatography Columns , GC Columns , Fused Silica Capillary ... .Click here to visit our GCxGC column combination guide....
...gcxgc-column-kit ... GCxGC Selectivity Kit, 0.18 mm ... Chromatography Columns , GC Columns , Fused Silica Capillary ... .Click here to visit our GCxGC column combination guide....
...gcxgc-column-kit ... GCxGC Selectivity Kit, 0.25 mm ... Chromatography Columns , GC Columns , Fused Silica Capillary ... .Click here to visit our GCxGC column combination guide....
polar phase; Crossbond polyethylene glycol
...15115, structure_gc_stabilwax.png ... Stabilwax Secondary Columns for GCxGC ... Chromatography Columns , GC Columns , Fused Silica Capillary ... Learn more about Restek GCxGC products. ... Convenient 2 m length is ideal for use as a secondary column in GCxGC analyses...
midpolarity phase; Crossbond trifluoropropylmethyl polysiloxane
...15115, structure_gc_rtx200.png ... Rtx-200 Secondary Columns for GCxGC ... Chromatography Columns , GC Columns , Fused Silica Capillary ... Learn more about Restek GCxGC products. ... Convenient 2 m length is ideal for use as a secondary column in GCxGC analyses...
midpolarity Crossbond phase
... capillary GC columns were designed specifically to be the best columns available for exceptional inertness ... 15115, structure_gc_rxi17silms.png ... Rxi-17Sil MS Secondary Columns for GCxGC ... Chromatography Columns , GC Columns , Fused Silica Capillary ... .Learn more about Restek GCxGC products. ... Convenient 2 m length is ideal for use as a secondary column in GCxGC analyses...
low-polarity phase; Crossbond 1,4-bis(dimethylsiloxy)phenylene dimethyl polysiloxane
... capillary GC columns were designed specifically to be the best columns available for exceptional inertness to oxidation. Rxi-5Sil MS columns are ideal for GC/MS applications requiring high sensitivity, including use ... 15115, structure_gc_rxi5silms.png ... Rxi-5Sil MS Secondary Columns for GCxGC ... Chromatography Columns , GC Columns , Fused Silica Capillary ... .Learn more about Restek GCxGC products. ... Convenient 2 m length is ideal for use as a secondary column in GCxGC analyses .Engineered to be a low bleed GC/MS column.Excellent inertness for active compounds.General...
nonpolar phase; Crossbond dimethyl polysiloxane
... capillary GC columns were designed specifically to be the best columns available for exceptional inertness ... 15115, structure_gc_rxi1ms.png ... Rxi-1ms Secondary Columns for GCxGC ... Chromatography Columns , GC Columns , Fused Silica Capillary ... .Learn more about Restek GCxGC products. ... Convenient 2 m length is ideal for use as a secondary column in GCxGC analyses...
low polarity proprietary phase
... capillary GC columns were designed specifically to be the best columns available for exceptional inertness molecular weight compounds with sensitive GC-MS systems, including ion trap detectors. Excellent efficiency ... Rxi-XLB Secondary Columns for GCxGC ... Chromatography Columns , GC Columns , Fused Silica Capillary ... .Learn more about Restek GCxGC products. ... Convenient 2 m length is ideal for use as a secondary column in GCxGC analyses...
Restek is your one source for 2D gas chromatography! Also known as GCxGC, comprehensive two-dimensional gas chromatography is a powerful technique that combines two independent separations to accurately analyze highly...
...Restek GCxGC Columns Your One Source for 2D Gas Chromatography Primary GCxGC Columns (In order 10623 Secondary GCxGC Columns (In order of increasing polarity) Phase Length ID df temp. limits...
...GCxGC Columns Your One Source for 2D Gas Chromatography Why use GCxGC ............................11 Hydrocarbons in Gasoline......................12 Restek GCxGC Solutions..................13...
Fingerprinting Crude Oils and Tarballs using Biomarkers and Comprehensive Two-Dimensional Gas Chromatography (PDF 2138kB)
... of GCxGC provides enhanced specificity and peak capacity with increased resolving power that can separate diagnostic biomarkers from potential isobaric interferences. Also, GCxGC provides a structured chromatogram...
High Quality Analysis of Pesticides in Marijuana Using QuEChERS, Cartridge SPE Cleanup, and GCxGC-TOFMS (PDF 672kB)
... Columns Increase Separation Power for More Accurate Pesticide Results GCxGC is a powerful orthogonal GCxGC system. More important though is separating pesticides from potential isobaric matrix...
Evaluation of Dispersive and Cartridge Solid Phase Extraction (SPE) Cleanups for Multiresidue Pesticides in QuEChERS Extracts of Finished Tobacco Using GCxGC-TOFMS (PDF 4409kB)
...-of-flight mass spectrometry (GCxGC-TOFMS) as the determinative technique . Analyzing tobacco using GCxGC through a more extensive cleanup. By coupling the GCxGC to the time-of-flight mass spectrometer we have...
....restek.com/rxi Restek GCxGC Columns: Your One Source for 2D Gas Chromatography Why Use GCxGC? GCxGC is a powerful samples. GCxGC involves two columns with differing stationary phase selectivity (orthogonal...
..., also known as GCxGC, is a powerful technique with a great deal of potential for improving separations —of components. While GCxGC is still considered emerging technology and is used primarily in research ... Comprehensive 2D GC, also known as GCxGC, is a powerful technique with a great deal of potential thousands—of components. While GCxGC is still considered emerging technology and is used primarily...
... switching valves and/or GCxGC modulators in certain models restrict the placement of the GC Accelerator GC Accelerator Kit cat.# 23849 The Restek GC Accelerator kit (Figure 1) reduces oven volume...
ChromaBLOGraphy: Tarballs! GCxGC and Environmental Forensics…
I haven’t seen my colleague Chris English this excited in quite a while, since we got tarballs from the Florida panhandle to analyze by a variety of methods, including GCxGC-FID. In fact, I thought he’d post a blog by now on this subject, but since he hasn’t, I’m stepping in! I analyzed multiple tarballs “extracted” [...]
Going to ISCC & GCxGC in Fort Worth this year? Don’t miss these presentations by Restek’s expert chromatographers. Stop by our booth or attend a presentation—we’re excited to share our research and discuss solutions to your toughest chromatography challenges! … Continue reading
Go to our ISCC / GCxGC / Riva page for a sneak peek at what we’ll be up to during this year’s show. You can also read abstracts for all of our lectures, easily contact the presenters, … Continue reading
Visit www.restek.com/ISCC to learn more about our vendor seminar and lunch, see our list of presentations, review technical abstracts, contact the presenters directly, and easily access the ISCC / GCxGC website.
ChromaBLOGraphy: GCxGC is the Star at 4th Multidimensional Chromatography Workshop!
My colleagues and I made the road trip to the Ontario Ministry of the Environment in Toronto for the 4th Multidimensional Chromatography Workshop. This workshop organized by Eric Reiner at the MOE is a veritable who’s who in the world of GCxGC. I personally love going to this workshop because of the wide variety of [...]
ChromaBLOGraphy: More Tarballs, GCxGC, and Hopane and Sterane Biomarkers
I was hoping someone would challenge me on my last post about fingerprinting oil spills through tarballs that might originate from the BP Deepwater Horizon event. I showed a couple of tarball GCxGC-FID chromatograms on Rxi-5ms x Rxi-17Sil MS, which looked quite dissimilar. But could they originate from the same oil spill? It is possible, [...]
Author(s): Jack Cochran, Jan Pijpelink Published By: Petro Industry News Year of Publication: 2011 Link: http://www.restek.com/Technical-Resources/Technical-Library/Petroleum-Petrochemical/petro_pin072011 Abstract: Analysis of sulfurs in diesel provides a good demonstration of the power of GCxGC for complex petro matrices. Increased peak capacity allows identification of sulfur … Continue reading
ChromaBLOGraphy: Restek Launches New GCxGC Column Program
In an ongoing effort to be the leader in GCxGC columns, Restek now offers secondary columns in convenient 2m lengths for 0.15mm x 0.15µm, 0.18mm x 0.18µm, and 0.25mm x 0.25µm, for a good variety of orthogonal stationary phases. Sorry for the sales pitch, readers, but hopefully you GCxGCers will forgive me when you visit [...]
ChromaBLOGraphy: The Promise of True Peak Capacity Increase GCxGC Realized
I mentioned in my last ChromaBLOGraphy post, Phthalate-Free Personal Care Products?, that we used GCxGC-TOFMS to determine phthalates in a Las Vegas Wash water sample. While it doesn’t dive into specific compound identification, we recently published the first demonstration of a near theoretical maximum peak capacity gain for GCxGC (approximately 9x) in an open access […]
Fingerprinting Crude Oils and Tarballs using Biomarkers and Comprehensive Two-Dimensional Gas Chromatography
... of GCxGC provides enhanced specificity and peak capacity with increased resolving power that can separate diagnostic biomarkers from potential isobaric interferences. Also, GCxGC provides a structured chromatogram ... Comprehensive two-dimensional gas chromatography time-of-flight mass spectrometry (GCxGC...
Last week at the 8th GCxGC Symposium, in conjunction with the 35th International Symposium on Capillary Chromatography, Don Patterson, Jr. was awarded the inaugural GCxGC Scientific Award. This award was cosponsored by Restek and LECO. Don retired from the Centers for Disease Control and Prevention (CDC) after an illustrious career specializing in human exposure assessment [...]
ChromaBLOGraphy: Multiply Your Separation Power with GCxGC and Selective Columns
An elegant way to solve complex separation problems is comprehensive two-dimensional GC (GCxGC). GCxGC increases peak capacity with two independent separations in one analysis. GCxGC uses a serial configuration of orthogonal stationary phases separated by a thermal modulator. A separation is performed on the first column, and effluent from the first column is repeatedly/quickly focused [...]
ChromaBLOGraphy: Restek at the 40th International Symposium on Capillary Chromatography and 13th GCxGC Symposium
Restek is proud to have numerous presentations in the orals scientific program for the 4oth ISCC and 13th GCxGC Symposium, which will take place in Riva del Garda, Italy in May. Exploding a Peak Capacity Increase Record by Using Hydrogen Carrier Gas for Comprehensive Two-Dimensional Gas Chromatography – Time-of-Flight Mass Spectrometry (Jack Cochran, Julie Kowalski, Christopher […]
Evaluation of Dispersive and Cartridge Solid Phase Extraction (SPE) Cleanups for Multiresidue Pesticides in QuEChERS Extracts of Finished Tobacco Using GCxGC-TOFMS
... spectrometry (GCxGC-TOFMS) as the determinative technique . Analyzing tobacco using GCxGC proved issues with extracts that have not gone through a more extensive cleanup. By coupling the GCxGC ... EChERS extracts of finished tobacco products using GCxGC-TOFMS. Cleanup with dSPE tubes containing 7.5 mg of GCB...
ChromaBLOGraphy: Petroleum Biomarkers and Tarballs at the 36th International Symposium on Capillary Chromatography and the 9th GCxGC Symposium
I’d like to invite my colleagues to a preliminary view of an upcoming presentation in Riva del Garda, Italy for the 36th International Symposium on Capillary Chromatography and the 9th GCxGC Symposium. We’ve been working on characterizing tarballs that could have originated from the Deepwater Horizon oil spill in the Gulf of Mexico in 2010. [...]
ChromaBLOGraphy: GCxGC-TOFMS of Riser Pipe Oil from BP Gulf Oil Spill
I recently analyzed an oil sample collected by an ROV from the riser pipe at the BP Gulf oil spill site using GCxGC-TOFMS, a powerful multidimensional technique capable of characterizing complex samples that defy one-dimensional GC-MS. The GCxGC column setup was a 30m x 0.25mm x 0.25µm Rxi-17Sil MS in the first dimension with a [...]
ChromaBLOGraphy: First GCxGC Separation of PAHs Triphenylene and Chrysene, and Benzo [b], [k], and [j] fluoranthenes Using the New Rxi-PAH GC Column
Polycyclic aromatic hydrocarbons (PAHS) are carcinogenic, mutagenic, and teratogenic environmental contaminants. But not all PAHs are created equal, so the European Food Safety Authority (EFSA) suggests analysis of the PAH4, benz[a]anthracene, chrysene, benzo[b]fluoranthene, and benzo[a]pyrene, to represent the majority of the toxicity in any food sample. Unfortunately, some of these PAHs coelute with other isobaric [...]
Comparing Pesticide Residues in Amish and Commercially Grown Strawberries and Spinach Using QuEChERS, Various dSPE Sorbents, and GC-TOFMS (PDF 1781kB)
... 4D GCxGC-TOFMS was used for GC-TOFMS analysis and all data were processed with ChromaTOF software /sec Instrument LECO Pegasus 4D GCxGC-TOFMS Notes Sample Preparation: Sample: 10 g of homogenized strawberries...
News: Comprehensive Two-Dimensional Gas Chromatography Time of Flight Mass Spectrometry (GCxGC-TOFMS) for Environmental Forensic Investigations in Developing Countries
Author(s): Jayne de Vosa, Roger Dixonb, Gerhard Vermeulenb, Peter Gorst-Allmanc, Jack Cochrand, Egmont Rohwere, Jean-Francois Focantf a Organic and Bio-Analysis Group, Metrology in Chemistry Area, National Metrology Institute of South Africa, Private Bag X34, Lynnwood Ridge 0040, South Africa b … Continue reading
ChromaBLOGraphy: Finally! A True Peak Capacity Increase for GCxGC
An ongoing controversy in comprehensive two-dimensional gas chromatography (GCxGC) is whether a true peak capacity increase has ever been achieved. You can read all about it in the article cited below, but in summary, Blumberg et. al state that a properly optimized one-dimensional (1D) GC system produces higher peak capacities than an improperly optimized GCxGC [...]
ChromaBLOGraphy: Julie Kowalski Presents FPRW Poster on PAHS in Sugarcane Products: QuEChERS, GC-MS, GCxGC-TOFMS, Rxi-17Sil MS
Reporting again from the Florida Pesticide Residue Workshop with the news that Julie Kowalski of Restek’s Innovations group just presented the poster, “Comprehensive Screening for PAHs in Sugarcane Products after QuEChERS with Sweet Separations using an Rxi-17Sil MS GC Column, GC-MS, and GCxGC-TOFMS”. This poster represents the combined work of a great team of colleagues, [...]
ChromaBLOGraphy: Young GCxGC Scientist, Adam Merrick, Ties for First in Chemistry at Berrien County Science and Engineering Fair with Olive Oil-Fatty Acids Poster
I’m proud and lucky to work with a group of fantastic, young, enthusiastic, creative scientists at Restek in our Innovations group, including Amanda Rigdon, Corby Hilliard, Jason Thomas, Julie Kowalski, Michelle Misselwitz, Scott Grossman, Sharon Lupo, and Ty Kahler (sorry, Barry and Chris and Rick, you guys ain’t young anymore, but you’re still fantastic and [...]
ChromaBLOGraphy: GCxGC-FID of a Petroleum Diesel and Biodiesel Blend: Rtx-200 x Rxi-17Sil MS and Rxi-5ms x Rxi-17Sil MS
One of the benefits of going to the 8th GCxGC Symposium and 35th International Symposium on Capillary Chromatography is that you not only get to hear presentations by experts like Professor John Seeley of Oakland University, but you also get to interact with those same experts outside of the talks, which is a great learning [...]
Large Volume Splitless Injection Using an Unmodified Split/Splitless Inlet and GC-TOFMS for Pesticides and Brominated Flame Retardants (PDF 1051kB)
... Acquisition Rate: 10 spectra/sec Instrument LECO Pegasus 4D GCxGC-TOFMS Notes Carrier Gas Flow: 2 /sec Instrument LECO Pegasus 4D GCxGC-TOFMS Notes Carrier Gas Flow: 2 mL/min. corrected constant flow via...
News: Evaluation of Dispersive and Cartridge Solid Phase Extraction (SPE) Cleanups for Multiresidue Pesticides in QuEChERS Extracts of Finished Tobacco Using GCxGC-TOFMS
Author(s): Michelle Misselwitz, Jack Cochran, and Julie Kowalski Restek Corporation Published By: Restek Corporation Year of Publication: 2013 Link: http://www.restek.com/Technical-Resources/Technical-Library/Foods-Flavors-Fragrances/fff_FFAN1823-UNV Abstract: Tobacco is a high-value production crop for the United States and ranks 6th in the amount of pesticides applied per … Continue reading
ChromaBLOGraphy: MM’s QuEChERS cSPE GCxGC-ECD of PCBs and PBDEs at FPRW, or, Why Does this Blog Title Only Consist of Acronyms?
I only have time for a brief report from the Florida Pesticide Residue Workshop as I get ready to go to a full day of talks and meetings. Michelle Misselwitz of Restek’s Innovations group presented the poster, “The QuEChERS Extraction Approach and Comprehensive Two-Dimensional Gas Chromatography of Halogenated Persistent Organic Pollutants in Cow Milk and [...]
...: 5 spectra/sec. Instrument LECO Pegasus 4D GCxGC-TOFMS Notes Sample Preparation: Wetting:1 g /sec. Instrument LECO Pegasus 4D GCxGC-TOFMS Notes Sample Preparation: Wetting: 1 g of dandelion root powder...
ChromaBLOGraphy: Peak Capacity and Selectivity in Gas Chromatography
I recently had the pleasure of hearing Professor Taduesz Gorecki from the University of Waterloo lecture on comprehensive two-dimensional gas chromatography (GCxGC). One of his chief areas of research is on the GCxGC modulator, which is essentially the “injector” for the second dimension column in this multidimensional chromatography approach. A twist on the usual process from Taduesz […]
ChromaBLOGraphy: Which GC instrument should I use for the analysis of pesticides in herbal tea? GC-MS/MS or GCxGC-TOFMS?
You may remember a while ago I posted a blog about the analysis of herbal tea using QuEChERS and GCxGC-TOFMS. The LECO Pegasus GCxGC-TOFMS is a great instrument for analyzing complex samples because of the comprehensive chromatographic separation achieved (two columns with different selectivities). The GCxGC-TOFMS also excels at non-target screening of compounds. Lucky for […]
ChromaBLOGraphy: Comprehensive Pesticide Screening Using QuEChERS, LC-MS/MS, and GCxGC-TOFMS at PittCon 2010
A recent collaboration with Applied Biosystems used a sensitive LC-MS/MS (4000 QTRAP) with a Restek Ultra Aqueous C18 column as the instrumental determination step for pesticides in QuEChERS extracts of red bell pepper, lemon, spinach, hazelnuts, raisins, and cucumber. Those same QuEChERS extracts were analyzed by a LECO Pegasus 4D GCxGC-TOFMS with Rxi-5Sil MS and [...]
ChromaBLOGraphy: Quantifying FAMEs at ppm Levels in a Petroleum Diesel and Biodiesel Blend with GCxGC-FID and Rtx-200 x Rxi-17Sil MS
I promised in the previous blog on petroleum diesel:biodiesel analysis using GCxGC-FID to tell you why it’s important to determine fatty acid methyl ester (FAME) levels in some fuel blends. It’s because the US Federal Aviation Administration (FAA) has set a maximum limit of 30 ppm for FAME in aviation fuel. FAMEs can cause fuel [...]
My Restek colleagues Julie Kowalski, Michelle Misselwitz, and Amanda Rigdon, along with Professor Frank Dorman from The Pennsylvania State University (PSU), report here what we believe is the first QuEChERS extraction of marijuana, with subsequent analysis using GCxGC-TOFMS. We were assisted in this task by Randy Hoffman, a Police Officer Specialist/Evidence Technician at PSU, who [...]
High-Quality Analysis of Pesticides in Cannabis Using QuEChERS, Cartridge SPE Cleanup, and GCxGC-TOFMS
... Orthogonal GC Columns Greatly Increase Separation Power for More Accurate Pesticide Results GCxGC broadly in both dimensions, providing a highly orthogonal GCxGC system. More important though ... challenging due to matrix complexity. The use of QuEChERS, cartridge SPE cleanup, and GCxGC-TOFMS as presented...
Analytical Method for Polycyclic Aromatic Hydrocarbons (PAHs) in Yerba Mate Tea Using Modified QuEChERS, Solid Phase Extraction and GC-TOFMS and GC-MS/MS (PDF 634kB)
... of incurred PAHs. Gas Chromatograph-Flame Ionization Detection GC-FID (GCxGC-FID instrument, LECO : 5 spectra/sec Instrument LECO Pegasus 4D GCxGC-TOFMS Peaks tR (sec) 1. Benz[a]anthracene 1...
Ensure Successful Polycyclic Aromatic Hydrocarbon (PAH) Analysis—Choose Specialized Rxi-PAH Columns (PDF 7240kB)
...; Acquisition Range: 45-550 amu; Spectral Acquisition Rate: 5 spectra/sec; Instrument: LECO Pegasus 4D GCxGC . For complete instrument conditions, visit www.restek.com and enter GC_FF1223 in the search. Red line = oven...
ChromaBLOGraphy: 3rd Multidimensional Chromatography and GCxGC Workshop at Ontario Ministry of Environment in Toronto
The 3rd Multidimensional Chromatography and GCxGC Workshop took place at the Ontario Ministry of the Environment (MOE) in Toronto, Ontario, Canada on January 10, 2012. The excellent lecture program was enjoyed by over 150 attendees and is listed below. Restek helped sponsor the workshop, and contributed three speakers this year due to our extensive work with [...]
ChromaBLOGraphy: Pesticides in Dietary Supplements
I was at the Recent Advances in Food Analysis conference in Prague last week and presented work on analyzing pesticides in dietary supplements, a very important subject given that FDA is moving to regulate these products. They are very complex herbal, botanical, etc. materials, which makes looking for trace level components very tricky. My colleagues, [...]
ChromaBLOGraphy: Restek’s EZGC Online Suite that includes the Method Translator and Flow Calculator, and a Chromatogram Modeler, wins a TASIA Award – Chris Nelson, One of the Suite Builders
The Analytical Scientist is a very smartly produced scientific magazine full of interesting articles, including many on chromatography. I’ve had the pleasure of working with two of the minds behind this publication, Rich Whitworth and Frank van Geel, on a TAS GCxGC contribution, and have been impressed with the volume of quality work they’ve put […]
ChromaBLOGraphy: International Network of Environmental Forensics Conference – Cambridge, UK – The Invention of Mass Spectrometry and J.J. Thomson
I’m writing this post from St. John’s College at the University of Cambridge in the United Kingdom where I will be speaking at the International Network of Environmental Forensics Conference tomorrow on polychlorinated biphenyl (PCB) analysis with parallel dual-column comprehensive two-dimensional gas chromatography – time-of-flight mass spectrometry (2GCxGC-TOFMS). I could wax on and on about […]
News: Fingerprinting Crude Oils and Tarballs using Biomarkers and Comprehensive Two-Dimensional Gas Chromatography
Author(s): Michelle Misselwitz, Jack Cochran, Chris English, and Barry Burger Restek Corporation Published By: Restek Corporation Year of Publication: 2013 Link: http://www.restek.com/Technical-Resources/Technical-Library/Petroleum-Petrochemical/petro_PCAN1789-UNV Abstract: Petroleum biomarkers are “molecular fossils” that can be analyzed with gas chromatography to fingerprint crude oil. Fingerprints … Continue reading
ChromaBLOGraphy: High Quality Analysis of Pesticides in Marijuana using QuEChERS, Cartridge SPE Cleanup, and GCxGC-TOFMS
Recently we reported on what we believe is the first application of QuEChERS for marijuana, using it for potency analysis with GCxGC-TOFMS. Ultimately, the plan was to determine pesticides via the QuEChERS approach, combining it with cartridge SPE cleanup as we did for dietary supplements, since sample complexity would defeat the typical dispersive SPE cleanup [...]
ChromaBLOGraphy: 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 [...]
ChromaBLOGraphy: 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 [...]
ChromaBLOGraphy: Preserving the First Dimension Separation in GCxGC
I mentioned in a recent blog post that to maximize peak capacity in GCxGC the first dimension separation needs to be preserved by having a very short second dimension separation (short modulation time), often on the order of 2 sec or less, even. While maximizing peak capacity can be very important when trying to characterize a complex […]
ChromaBLOGraphy: Separation of m- and p- Xylenes by Gas Chromatography on Dimethyl Polysiloxane – Is it Possible?
One of the first gas chromatography (GC) projects I tackled when I worked for the US Environmental Protection Agency a few decades ago was the separation of m- and p- xylenes for a microbial degradation experiment. I did it by purge-and-trap GC with whole column cryotrapping, a technique invented by Jim Pankow at the Oregon [...]
From October 15–19, 2012, the U.S. Environmental Protection Agency (EPA) will hold its 22nd Annual Quality Assurance Conference in Region 6, Dallas, TX. Two Restek chemists, Michelle Misselwitz and Chris Rattray, will be making the trip south to present some … Continue reading
Researchers at the University of Maryland and the US Department of agriculture may have uncovered the mystery of high mortality in honeybees. These insects are responsible for pollinating over 130 different crops in the US alone. Loss of this pollinator species could cost the US $15 Billion annually. The EU (European Union) issued a […]
ChromaBLOGraphy: I ain’t feelin’ the blues today…St Louis Metabolomics Symposium
I just returned from the St Louis Metabolomics Symposium that was held earlier this week. The event was sponsored by LECO, AB SCIEX, Gerstel, Monsanto and Restek. Metabolomics is the study of the small molecules or metabolites resulting from specific cellular processes. The idea is that metabolite profiles can help reveal biological processes including disease [...]
ChromaBLOGraphy: Gimme some sugar, baby. Analyte Protectants in Pesticide Analysis.
Scott’s post, “The Solvent Shield”, reminds me of using “analyte protectants” (APs) for determining pesticides in baby food via QuEChERS and GCxGC-TOFMS. A matrix-enhanced response occurs for many polar pesticides in food extracts, versus solvent alone, leading analysts to use “matrix-matched standards” (MMSs) for quantification (standards prepared in pesticide-free food extracts). Sugars and other hydrogen-bonding [...]
ChromaBLOGraphy: 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 [...]
Author(s): Michelle Misselwitz, Jack Cochran, Julie Kowalski Restek Corporation Published By: Chromatography Techniques Year of Publication: 2014 Link: http://www.chromatographytechniques.com/articles/2013/12/quechers-gc-smoke-out-tobacco-pesticides Abstract: Pesticides are used heavily on tobacco in order to increase crop production value; however, limited regulation creates the potential for high … Continue reading
... GCxGC analysis of organochlorine pesticides combines primary column and confirmation column results Instrument: LECO GCxGC ... Guest editor Dr. Phil Marriott tells us the three primary contributions ascribed to GCxGC...
ChromaBLOGraphy: GC-MS with Hydrogen Carrier Gas
At the LECO Australia Separation Science Users Group Meeting last Friday in Sydney, my colleague from South Africa, Peter Gorst-Allman, made a presentation on using hydrogen carrier gas for GC-TOFMS and GCxGC-TOFMS. His preliminary results were quite encouraging, as he noted no obvious deterioration of mass spectra quality for a wide variety of compounds, including [...]
ChromaBLOGraphy: Environmental Forensics, Water Pollution, Pansteatitis and Crocodiles dying in Kruger National Park
I’ve been fortunate enough to travel in South Africa and see some of its impressive wildlife, including crocodiles in Kruger National Park, the country’s premiere wildlife watching destination. During one of my trips there, a colleague with the South African Police Service, Roger Dixon, was involved in an environmental forensics study to determine why massive [...]
ChromaBLOGraphy: Niel Malan from University of Pretoria wins Best Student Poster Prize at ChromSAAMS 2012 in South Africa
I was proud to be invited to join my colleagues Chris Marvin (Environment Canada), Jef Focant (University of Liege, Belgium), and Rob Trengove (Murdoch University, Australia) as a “best student poster” judge for the recent ChromSAAMS conference on gas chromatography and mass spectrometry in South Africa. We reviewed 13 high quality posters and made our [...]
ChromaBLOGraphy: Pesticides on Roses – The QuEChERS Sample Preparation Approach
A couple of years ago we had a summer intern in our Innovations lab, Shane Stevens, whose project with us was developing a QuEChERS sample preparation approach for pesticides on cut flowers, including roses. He presented his work at the 12th Annual Environmental Chemistry Student Symposium at The Pennsylvania State University (PSU) with the distinction of [...]
Last week I had the honor to present my work at the 31st International Symposium on Halogenated Persistent Organic Pollutants (Dioxin 2011). While it is still a work in progress, Jack Cochran and I evaluated the QuEChERS extraction approach with a silica SPE cleanup for PCBs and BFRs in cow milk and human breast milk. [...]
ChromaBLOGraphy: Are fatty acids overwhelming your QuEChERS dSPE PSA cleanup and causing issues in your GC analysis? Get more cleanup capacity with cartridge SPE cleanup!
Fatty acids are important molecules in the human body because they are used as a source of fuel. There are many food sources of both “healthy” and “unhealthy” fatty acids. Many sources of dietary fatty acids come from fruits, vegetables, seeds, nuts, and animal fats. The QuEChERS methodology was developed to analyze pesticides in fruits […]
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 […]
ChromaBLOGraphy: US Drug Enforcement Administration Exerts Federal Control Over Synthetic Marijuana Compounds (JWH-type; CP-47,497; and Cannabicyclohexanol)
I heard on the news the other day that the DEA is taking action to control synthetic marijuana compounds such as JWH-018, JWH-073, and JWH-200, in addition to a couple others. It hasn’t been that long ago that herbal “incenses” that provide a pot-like high when smoked popped up for sale on the internet, and [...]
ChromaBLOGraphy: Dioxin 2011 Conference Starts Today in Brussels
The 31st International Symposium on Halogenated Persistent Organic Pollutants, aka Dioxin 2011, starts today in Brussels with the theme “Persistent Organic Pollutants (POPs) Science in the Heart of Europe”. Restek will have an exhibit booth (nicely done by our Graphics team; more on that tomorrow!), that showcases our Rxi-5Sil MS (60m x 0.18mm x 0.10µm) [...]
ChromaBLOGraphy: Jacob de Boer Gives Opening Lecture at the 7th International Symposium on Flame Retardants (BFR 2015)
Jacob de Boer from the VU University, Institute for Environmental Studies, Amsterdam, The Netherlands, gave the first plenary lecture at BFR 2105 in Beijing, “Recent Trends in the Use and Environmental Occurrence OF Flame Retardants: More – Less Persistent – More Toxic?” As expected, his thought-provoking talk covered a wide range of brominated flame retardants […]
ChromaBLOGraphy: Spring is finally here! Unfortunately so are the ticks…
After a long and cold winter here at the Restek headquarters in Bellefonte, PA, USA it seems that spring is finally here! It is so nice this time of year to get outside and enjoy the weather and the beautiful outdoors that Pennsylvania has to offer. Unfortunately after a hike in the woods there is […]
ChromaBLOGraphy: Wildfires in the Western United States: The smoke can be as dangerous as the flames, especially for firefighters.
The drought continues and wildfires are raging across the Western United States. In Washington State alone, the wildfires have burned over 1400 square miles (that’s 3600 km2). Brave men and women from across the United States are coming to the aid and trying to contain these historical fires. Unfortunately lives of the firefighters are in […]
ChromaBLOGraphy: Phthalate-Free Personal Care Products?
In her recent ChromaBLOGraphy posts, Minimizing Phthalate Interferences Using the Rtx-CLPesticides/Rtx-CLPesticides2 Columns and EPA Regulated Phthalates FREE?, my colleague Dan Li pointed out the ubiquitous nature of phthalates in our world because of their widespread use in plastic consumer products, and that phthalates likely have adverse human health effects, including as endocrine disruptors. Any of […]
News: Determination of Emerging Contaminants in Wastewater Utilizing Comprehensive Two-Dimensional Gas-Chromatography Coupled with Time-of-Flight Mass Spectrometry
Author(s): Sarah Prebihalo1, Adrienne Brockman1, Jack Cochran1,2, Frank L. Dorman1,3 1. Pennsylvania State University, Forensic Science Program 2. Restek Corporation 3. Pennsylvania State University, Department of Biochemistry and Molecular Biology Published By: Journal of Chromatography A Year of Publication: 2015 … Continue reading
.... People use extremely complex techniques like GCxGC, but many don’t even know how many plates a certain like GCxGC-TOF and produce very impressive data. I have always respected Nol Venema of Akzo...
ChromaBLOGraphy: 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, […]
Like every other year the most famous meeting on capillary separation techniques was organized in the USA.; This time it was in Palm Springs. When you visit this place you will understand where the name comes from. (picture 1). Palm trees like to have their feet in water and their heads in the sun. In [...]
We have a very bright guy named Jaap de Zeeuw who works for Restek. Years ago he invented a system for low-pressure gas chromatography by where he used a 0.53mm GC column attached to a mass spectrometer, and a restrictor column (e.g. 0.50m x 0.10mm) press-fitted to that column and installed in a split/splitless GC [...]
ChromaBLOGraphy: 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 [...]
ChromaBLOGraphy: Join the Restek CAC and Separate Triphenylene and Chrysene and other PAHs, and Many Other Compounds
Restek just founded the Coalition Against Coelution (CAC) based around their highly selective stationary phases for GC and LC. If you stroll around on the website and the blog, you’ll find the CAC manifesto in action, whether it is the Rtx-Dioxin2 GC column, with its TCDD and TCDF specificity; the Rtx-CLPesticides GC columns, which are [...]
The AOAC annual meeting is fast approaching. Beginning this Sunday, September 30th and running through next Wednesday, October 3rd, the 2012 AOAC meeting in Las Vegas, Nevada promises to be another exciting conference. The final program has been announced and … Continue reading
As in years past, Restek sent a contingent of environmental and air chromatography experts to the National Environmental Monitoring Conference (NEMC). This year’s event took place in Washington, DC, and featured talks from our own Michelle Misselwitz, Jason Herrington, and … Continue reading
ChromaBLOGraphy: World Record Set for Longest Gas Chromatography Retention Time!
My colleague Jaap de Zeeuw holds a Guinness World Record certificate for making and applying the longest GC column ever, 1300m. That’s quite a feat and I’ve often wondered what the retention times were for that column when you consider the holdup time was probably on the order of hours instead of minutes. No matter […]
ChromaBLOGraphy: Who cut the cheese…and PCBs?
Polychlorinated biphenyls (PCBs) are organochlorine compounds having a double ring structure where one to ten chlorine atoms are substituted. At one time, these compounds where used as coolant fluids and in various products like electronics, paints and adhesives. These compounds are considered toxic because they have been linked to carcinogenic and mutagenic biological changes. Because [...]
ChromaBLOGraphy: Solvent Focusing – The Key to Successfully Implementing CSR-LVSI
It’s been over a month since my last post on Concurrent Solvent Recondensation – Large Volume Splitless Injection (CSR_LVSI), so I thought I would cover solvent focusing, a key element of the technique, today. The CSR-LVSI solvent peak widths are minutes larger than those seen in a typical 1 µL injection. Figure 1 shows the difference in solvent […]
Last week I presented an invited talk at the Chromatographic society in the UK. http://www.restek.com/news/view/?p=797 Alan Handley, driving force behind the GC meetings, gave me a working title: “Column selection: is there is more to life than using a boiling point column? The answer is clearly “yes”, not because I like chromatography but also […]
The year 1936 marks the beginning of organic geochemistry. It started with Alfred Treibs’ discovery of porphyrins in petroleum; compounds that closely resemble chlorophylls in plant matter. Another 25 years would pass before scientists recognized that these compounds, known as biomarkers, could reveal insights into the evolution of plants and animals spanning a time frame […]
Nearly 20,000 people attend Pittcon from over 90 countries and there is a staggering amount to see on the technical front. Luckily the show has the presentation titles on-line and easily searched in the PDF format. Simply enter in your search term and quickly find your area of interest. Below is an excel sheet that will [...]
ChromaBLOGraphy: 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 […]
ChromaBLOGraphy: Modifying QuEChERS for complicated matrices- Dry Samples
Before getting in to this discussion, I recommend reading my previous blog post first regarding classical applications for methods based on Quechers. https://blog.restek.com/quechers-dspe-selection-which-one-is-best/ QuEChERS methods were originally written to analyze pesticides in fruit and vegetable matrices, most of which have high water content and low fat content. More recently, the technique has been used for […]
Comparing Pesticide Residues in Amish and Commercially Grown Strawberries and Spinach Using QuEChERS, Various dSPE Sorbents, and GC-TOFMS
... Pegasus 4D GCxGC-TOFMS was used for GC-TOFMS analysis and all data were processed with ChromaTOF software SPE cleanup, and GC-TOFMS analysis were used to assess pesticide levels in strawberries and spinach from both ... QuEChERS extraction, dSPE cleanup, and GC-TOFMS analysis were used to assess pesticide residue...
Analytical Method for Polycyclic Aromatic Hydrocarbons (PAHs) in Yerba Mate Tea Using Modified QuEChERS, Solid Phase Extraction and GC-TOFMS and GC-MS/MS
... Detection GC-FID (GCxGC-FID instrument, LECO Corporation) was used to evaluate extraction solvents compounds and isobaric interferences was optimized on a high-phenyl stationary phase using both GC ... QuEChERS extraction and solid phase extraction sample cleanup. Both GC-TOFMS and GC-MS/MS techniques...
News: Comprehensive Two-Dimensional Gas Chromatography With a Multi-Capillary Second Dimension: A New Column-Set Format for Simultaneous Optimum Linear Velocity Operation
Author(s): Daniela Peroni1, Andjoe A.S. Sampat1, Wil van Egmond2, Sjaak de Koning3, Jack Cochran4, Roy Lautamo4, Hans-Gerd Janssen1,5 1. University of Amsterdam, 2. NLISIS, 3. LECO Corporation, 4. Restek Corporation, 5. Advanced Measurement and Data Modelling, Unilever Published By: Journal … Continue reading