Restek to Present at ExTech 2018

Restek is pleased to sponsor the 20th International Symposium on Advances in Extraction Technologies (ExTech) this year and will be presenting a technical talk on analyzing residual solvents in cannabis concentrates. You’ll find details about our presentation and new SPME Arrow technology below. We hope you can join us for this exciting conference on the cutting edge of sample extraction!


Thursday, June 21 (9:20-9:35 a.m.)

O_27     A Simple Approach to Analyzing Residual Solvents in Cannabis Concentrates via HS-GC


Colton Myers, Jason S. Herrington (presenter), Gary Stidsen, Ashlee Reese, Steve Kozel

For more information, email Jason Herrington.


Abstract: With more states legalizing the medical and recreational use of cannabis, analytical methodologies that will ensure consumers receive safe products are urgently needed. Currently, there is a growing trend in new cannabis formulations. These formulations increasingly use cannabis concentrates, which are made by extracting chemical compounds, such as delta-9-tetrahydrocannabinol (THC) and cannabidiol (CBD), from the cannabis plant. To do this, producers use a variety of solvents in their extraction processes. This study focused on analyzing residual solvents in cannabis concentrates with an approach similar to the USP <467> sample preparation technique. Residual solvents were also extracted with the more “classical” approach of HS-syringe and as well as with a large volume HS-SPME approach that utilized SPME Arrows. Comparison results and a simple solution for analyzing residual solvents in these complex matrices will be presented.


About SPME Arrows

The Restek PAL SPME Arrow system (patent pending) is a revolutionary change in microextraction that combines exceptional robustness with faster extraction times and trace-level sensitivity. In contrast to traditional SPME fibers, SPME Arrows contain significantly more phase volume, which allows more target analyte to be extracted in less time. In addition, the stainless steel construction, unique Arrow tip, inner stabilizing rod, and outer sheath design fully protect the phase, minimizing both mechanical damage and analyte loss during sample transfer.


Come see us at ExTech or contact your Restek representative for more information about SPME Arrows.

Fast, Sensitive LC-MS/MS Analysis of GHB and Related Compounds in Human Blood for Forensic Testing

Published By: Restek Corporation

Year of Publication: 2018



This straightforward method for LC-MS/MS analysis of gamma-hydroxybutyrate (GHB) and its precursors gamma-butyrolactone and 1,4-butanediol provides simultaneous analysis of all target compounds in a fast, 5- min cycle time. Good low-level sensitivity was obtained, ensuring accurate determination of endogenous levels and identification of exogenous drug consumption.

A Simple Way to Reduce Analysis Time in GC

Author: Jaap de Zeeuw

Published By: Restek Corporation

Year of Publication: 2018



There are several ways to decrease analysis time in GC. Reducing analysis time depends on the separations between the peaks of interest. In the case of enough separation, some efficiency can be traded for speed by:

  1. Using a shorter column length
  2. Operating the column at a higher flow rate or using flow programming to elute late-eluting compounds.

If the same efficiency is required, options are to:

  1. Use a faster carrier gas, i.e., hydrogen instead of helium
  2. Use a shorter capillary with a smaller bore—this produces similar efficiency with shorter run times.

In all of the above situations, analysis time is also limited by the maximum temperature programming that is allowed for the instrument used.