Archive for the ‘Miscellaneous’ Category

It May be Hot Outside, but Your Headspace Analysis Can Still Suffer from the Cold

Summer days are my favorite – hot, sunny, and full of fun. But one thing that’s really not fun is trying to track down contamination and/or carryover in your headspace-GC (HS-GC) system. I get questions about this topic pretty regularly, so I thought I would post a blog on the most common culprit for contamination […]

Simple Analysis of Bile Acids by GC-MS

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, especially liver and intestinal diseases. For instance, high levels of intestinal bile acids, in particular, […]

Changes in Elution Order between Phenols and Phenyl Acetates

In order to determine contamination levels for phenols in water, the French normalized method, NF EN 12673, recommends an in-situ derivatization with acetic anhydride, followed by extraction with hexanes. The derivatization process (diagrammed in Figure 1) converts the phenolic compounds into phenyl acetates, which perform much better on GC/MS columns such as the Rxi-5Sil, due […]

Think you must use RFID-tagged lamps? Think again!

The recent addition of Radio Frequency Identification tags (RFID tags) to detector lamps allows automatic reference and usage data collection to your system software. This is convenient but comes at a cost: up to 40% more for an OEM-tagged lamp compared to a Restek replacement lamp. At the time of the writing of this blog […]

Pesticide analysis for cannabis flower: method and data overview

Pesticides in cannabis has been a hot topic lately and we have been getting many requests for help with this analysis. We did work on pesticide residue testing in cannabis about 6 years ago. At that time, we were limited to testing our methods with a small amount of seized material. Recently, we have been […]

Need Help with QuEChERS: #AskRestek Twitter Q&A session

Just wanted to let everyone know we will be hosting a #AskRestek Twitter Q&A session about QuEChERS next week at 3:00 p.m. EST (12:00 noon PST) on Tuesday, May 3. QuEChERS is a great approach for sample preparation with lots of benefits. It is also very flexible which is nice but that can also make […]

Analysis of N2O (nitrous oxide) via GC: an update

Nitrous oxide (N2O), is commonly known as “laughing” gas, but is also used as a component in fuels in rockets and as an aerosol propellant. N2O is itself a stable gas and can be analyzed relative easy via gas chromatography. Often it is confused with “nitric oxide”, (NO). NO is a very reactive gas. When […]

Check out Dual Vespel® Ring Inlet Seals

Inlet seals are a critical component for ensuring a leak free seal at the base of a GC inlet.  For those of you who are using standard inlet seals on Agilent or Thermo Trace instruments, Restek also offers an alternative known as the Dual Vespel® Ring seal.  This seal features a Vespel® ring on each side […]

The “Breakdown” of Endrin and DDT for Non-Environmental Chemists

As the title makes clear, this post is aimed more at non-environmental laboratory personnel who are not familiar with US EPA methods.  If you are one of those environmental lab gurus who shudders at the sound of a “pesticide degradation check”, this is probably stuff you already know. Anyways, for the rest of you, you […]

SDS’s for 22010, 22011, 22014 and 22015 (Indicating Oxygen & Moisture traps/filters)

Even though we are not required to include a SDS (MSDS) for most of our products (articles), we often get asked for them for our gas filters/traps (for disposal information). Included below are the SDS’s for the following Restek catalog numbers: 22010 & 22011 (Indicating Oxygen traps/filters) 22010-22011 MSDS Restek       22014 & […]