Isomer detection on the basis of analyte adduct formation with the components of the mobile phase and tandem mass spectrometry

Injector port acylation of γ-hydroxybutyrate (GHB): Condition optimisation, source adjustments, and characterisation of the derivatives

For several years, gas chromatography-mass spectrometry (GC-MS) has been used to identify gamma-hydroxybutyrate (GHB) in forensic toxicology cases. However, under injector port conditions GHB can dehydrate into gamma-butyrolactone (GBL). Therefore, it is important for GHB to undergo a derivatisation reaction before an analysis to avoid the production of GBL; various analytical methods have been developed for the analysis of GHB but very few methods use acylation as a form of derivatisation. This study explores the optimisation of injector port acylation of GHB to improve its detectability and thermostability. By utilising trifluoroacetic acid anhydride (TFAA) and heptafluorobutyric acid anhydride (HFBA) to enhance the chromatography and mass spectra of the resulting derivatives. As a result, both reagents improved the detectability of GHB, with TFAA producing more predominant peaks within the chromatogram and HFBA offering a more complex mass spectrum. The optimal injector temperature was found to be 240 °C for both reagents, which significantly increased the derivatisation yields. These results demonstrate the effectiveness of injector port acylation as an alternative derivatisation route for GHB related drug cases.

Signal Separated Quantification of γ-Hydroxybutyrate With Liquid Chromatography-Tandem Mass Spectrometry in Human Urine and Serum as an Improvement of the Analyte Adduct Ion Based Quantification

The aim of the work was the development and validation of an LC-MS/MS γ-hydroxybutyrate (GHB) quantification method in urine and human serum by the use of the analyte adduct ion formation strategy. A combined detection with a conventional precursor ion in the negative electrospray mode and additionally GHB adduct ions with both sodium acetate and lithium acetate was in focus. Therefore GHB quantification based on separated MS/MS signals. Two tandem mass spectrometers representing different MS/MS generations (Sciex API 4000 QTrap and Sciex API 5500 QTrap) were used for method validation and comparison. Shimadzu HPLC Systems equipped with a Luna 5 µm C18 (2) 100 A, 150 mm × 2 mm analytical column were applied successfully for sample analyses. Infusion experiments were performed for adduct identification and analyte detection optimisation. Sample preparation could be limited to a simple and fast protein precipitation/sample dilution. An effective signal separated GHB quantification with three independent precursor ions representing separated areas of the mass spectrum was developed, validated according to forensic guidelines and applied in the routine. The developed and applied strategy resulted in a higher safety factor for the analyte quantification performed in the forensic toxicology. A relevant analytical improvement could be achieved with this alternative adduct based GHB analysis since a good correlation of analyte concentrations calculated on the basis of separated signals was stated as useful analytical information.

Interpol review of controlled substances 2016-2019

This review paper covers the forensic-relevant literature in controlled substances from 2016 to 2019 as a part of the 19th Interpol International Forensic Science Managers Symposium. The review papers are also available at the Interpol website at: https://www.interpol.int/content/download/14458/file/Interpol%20Review%20Papers%202019.pdf.