UCT presenting Workshop and Case Study Presentations at LTG (formerly London Toxicology Group) meeting in London, July 5

UCT is proud to announce its sponsorship of the United Kingdom’s LTG July 5th meeting.  LTG was founded in the 1970's in order to provide a forum for toxicologists around the United Kingdom to come together and discuss topics of interest regarding the field of forensic toxicology.  UCT maintains a significant presence for providing products and technical support for the forensic toxicology field.  As part of its sponsorship and commitment to the LTG and forensics in general, UCT’s Dr. Jeff Hackett will be offering our UCT SPE workshop as well as presenting a series of case studies highlighting the analysis of designer drugs.  The studies being presented employ two of UCT flagship sorbents (Clean Screen DAU for the analysis of Methoxetamine, and Clean Screen THC for AM-2201).

Need an alternative to Toxi-Tubes?

UCT is well recognized for excellence in SPE. It is also the premiere supplier for sample prep products to the Forensic / Clinical Toxicology Community. Recently, it was announced that a general drug screening tool, the Toxi-Tubes® from Agilent, is being discontinued this fall. UCT understands that this is putting a lot of pressure on analysts to search for an alternate pathway to prepare their samples.  UCT has always provided the ideal solution for extraction and analysis - the Clean Screen suite of SPE cartridges. Clean Screen DAU is the flagship sorbent for all types of confirmations; however, it can also be used as a sorbent for screens. It extracts all weak acids, neutrals, and bases resulting in clean, reproducible extracts. This front end effort makes for a cleaner injection port and detector source on your GC/MS and/or LC/MS meaning more instrument up time and less noise in your chromatograms. If time is of critical importance - UCT also offers the Clean Screen Xcel range of SPE tubes. This product line requires no tube pre-conditioning, just a simple sample load, wash, and elute process. In addition to products to ease your transition to a new extraction technique, UCT also has a team of in-house and field application specialists that can help you with your transition to a new and better sample preparation for your biological matrices. Contact us at info@unitedchem.com or call us at 215-781-9255 or 800-385-3153 to discuss how we can help you keep the samples moving through your lab.

Toxi-Tubes® is a registered trademark of Agilent Technologies, Inc.

Clean Screen DAU unravels the “Hook” Effect

The "Hook Effect" (or "hooking effect") is a phenomenon common to bimolecular detection systems involving saturable reagents (beads, labeled antibodies, streptavidin, etc.) used to capture specific binding partners or analytes. The hook effect occurs when an ELISA system is overwhelmed with the target analyte resulting in lower than expected or suppressed readings for high analyte concentration samples – potentially resulting in false negative results. This can be an issue in Forensic Toxicology where Immunoassay techniques are used as the primary screening methodology. It may lead to anomalous or erroneous results especially at high analyte concentrations. It can be resolved by using a second, separate analytical technique (e.g. GC-MS).

In order to evaluate any suspected “hooking” an analyst needs an extraction method with the capacity to handle high concentrations of drugs in realistic settings. In a recent report published in the Journal of Analytical Toxicology (e-published in June 2013), Dr. Sheila Dawling’s team (Department of Pathology, Microbiology, & Immunology; Vanderbilt  University Medical Center, Nashville, TN) looked at a presumed hook effect in the semi-quantitative DRI Oxycodone immunoassays in 14 urine samples with gas chromatography/mass spectrometry (GC-MS) >10,000 ng/mL. These samples included the index case, a false-negative  result with >75,000 ng/mL oxycodone . Dr. Dawling’s team employed UCT’s flagship Clean Screen DAU sorbent to isolate the drugs from real cases. Her methodology was based on an already validated method (Broussard et al. (Clinical Chemistry, 1997 43, 1029–1032)), which also employed the Clean Screen DAU to analyze codeine, morphine, hydrocodone, and hydromorphone as the trimethyl silyl oximes in urine. Using the premier SPE column available to forensic toxicologists, Dr. Dawling was able to correctly identify and correct this perceived “hook effect” by being able to quantify very high concentrations of the oxycodone in real samples. This report demonstrates why UCT is known for producing the finest SPE sorbents for use with real samples.