(1246-C) Chromatography Free Measurements Enabling Rapid Quantitation of Synthetic Cannabinoids in Urine
Tuesday, February 6, 2024
12:00 PM – 1:00 PM EST
Location: Exhibit Halls AB
Abstract: Ambient ionization investigators have developed a plethora of methods for qualitative analysis, imaging, and sample fingerprinting. Development of methods for quantitative analysis have been demonstrated, however for complex biological samples the absence of chromatographic separation and difficulties with matrix effects have limited application of the method. Utilizing current generation high throughput parallel sample processing technology with our high throughput sample movement robotics we demonstrate the utility of DART-MSMS for quantitative analysis. The determination of otherwise difficult to analyze synthetic cannabinoids in urine is demonstrated using a triple quadrupole mass spectrometer.
Using sample preparation of methods developed for determination of synthetic cannabinoids in urine by LC/MSMS analysis we have completed experiments to determine the utility of DART-MRM for these measurements. As in LC/MSMS a calibration series was prepared in triplicate by spiking certified drug-free urine with 18 synthetic cannabinoid standards of at concentrations ranging from 0.1-250 ng/mL. Deuterated AB-Pinaca added to each sample as an internal standard. As hydrolysis is a required step for this sample analysis a 50 µL Kura aliquot of enzyme solution was added to 500 µL of the pre-spiked certified aliquots of drug-free urine and the samples were incubated at room temperature for 20 minutes. Post-hydrolysis a 500 µL aliquot of 0.1 M Borax buffer (pH=10.4) and 2.5 mL 30:70 (ethyl acetate:n-chlorobutane) was added to each sample followed by a 30 second agitation. Samples were centrifuged at 4000 RPM for 10 minutes. The organic layer was transferred to glass vials and evaporated to dryness under N2 at 40°C followed by reconstitution in 100 µL MeOH. Reconstituted samples were vortexed for 30 seconds after which a 2 µL aliquot of each sample was pipetted onto the wire mesh surface of the QuickStrip HTS-96 screen and allowed to dry under nitrogen gas at 40°C for 15 minutes.
Rapid determination of each sample on the screen was completed by inserting the sample plate into the automated XY transmission stage of a EVOQ DART-TQ+ (Bruker Daltonics) triple quadrupole mass spectrometer. DART-MS-MS analysis was completing analysis in triplicate collecting a series of equal timed 30 second MRM acquisitions for each drug. Accuracy was evaluated by examining certified drug-free urine without detectable levels of the 18 substances at 2 levels within the linear range of each calibration series.
Previous investigations have documented the difficulties associated with using small volume samples and mixing labelled standards to those samples as an impediment to the use of ambient ionization methods. In this study we report results obtained by using current state-of-the-art sample prep and liquid handling technologies to add appropriate standards in order to permt accurate determination of drugs in urine samples for successful quantitative ambient ionization DART MSMS analysis.