Gamma hydroxybutyrate and CUQAX156

In the field of Forensic Toxicology, analysts are often asked to analyze for Gamma hydroxybutyric acid (GHB) in cases where drug facilitated crimes may have occurred. With this in mind, UCT is proud to announce that a validated method has been published in the Journal of Chromatography B (879 (2011) 3752– 3758) using Clean-Up QAX SPE columns . This methodology, developed in collaboration with a major crime laboratory, employs UCT's CUQAX156 column to extract GHB from human urine. With the use of an anionic exchange sorbent, Dr. Jeff Hackett and Albert Elian were able to extract GHB from only 50 microliters of urine down a concentration of 50 nanograms per milliliter. The procedure, performed on LC-MS/MS, produced very low matrix effects (less than 6 percent). The samples extracted from the SPE are of the highest quality, allowing instruments to stay cleaner, longer and permitting many more analyses to be performed.

CHQAX and Bisphosphonates in Australia

Clinical toxicologists often face the challenge of working to quantify difficult and low concentration medications in human beings. Falling into this category is the series of compounds known as Bisphosphonates. These pharmaceuticals are prescribed to counter the effects of bone disorders. Bisphosphonates are known to be difficult to analyze due to their phoshonic acid functional groupings and high polar character. One of the main issues with working with these types of materials is to produce a clean extract for analysis by modern instrumentation such as LC-MS/MS.

In Australia, a team lead by Dr. Sussan Ghassabian, PharmD has recently reported a validated method for the analysis of Bisphosphonates in human plasma (Journal of Chromatography B ( November 2011)). This procedure employs UCT's CHQAX solid phase extraction sorbent. The QAX column (hydroxy counter ion) is part of a range of Clean Up Anion Exchange Sorbents manufactured to the highest technical quality which also includes CUNAX (a weak anion exchanger) and CUPAX (a very weak anion exchange sorbent). In the case of Dr. Ghassabian's analysis, the phosphonic acid were efficiently held by the CHQAX, while interfering compounds could be rinsed away, offering a much cleaner environment for elution, and further analysis of the medications via on column derivatization.