Ultrafast qualitative screening of mitragynine, MDMA, and THC in complex matrices by green technology direct probe ionization mass spectrometry

Importance of the Topic

Rapid and reliable screening of illicit substances in complex sample types is critical for forensic, quality control, and harm-reduction applications. Traditional mass spectrometry workflows require extensive sample pretreatment and lengthy run times, increasing solvent consumption and analysis cost.

Objectives and Study Overview

The study aimed to develop and validate an ultrafast qualitative screening method for three representative substances—MDMA, mitragynine, and THC—in diverse matrices (drug sachets, beverages, and cannabis oil) using Shimadzu’s Direct Probe Ionization Mass Spectrometry (DPiMS) coupled to LCMS-8050.

Methodology and Instrumentation

The core instrument configuration comprised a DPiMS-8060 direct injection probe interfaced with an LCMS-8050 triple quadrupole mass spectrometer.

• Ambient ionization without chromatographic separation.
• Simple sample preparation: solvent mixing (methanol/chloroform or acid/base liquid–liquid extraction), brief filtration, and direct placement on the probe plate.
• Scheduled multiple reaction monitoring (MRM) with five transitions per analyte, 0.1 min time windows, and a total cycle time of 1 min per sample.

Main Results and Discussion

Fourteen real-case samples (six street drug sachets, seven beverages, one oil) were screened:

• All MDMA in sachets, mitragynine in beverages, and THC in oil were detected and confirmed via five MRM transitions with limits of detection ranging from 10 to 45 ppb.
• Comparative GC/MS analysis required 30 min per run and extensive extractions, while DPiMS achieved results in 1 min with minimal solvent use.
• Quantitative ion ratios and scheduled MRM ensured high selectivity and sensitivity, matching conventional reference spectra.

Benefits and Practical Applications

The DPiMS approach offers major advantages:

• Green technology: substantial reduction in organic solvent consumption and waste generation.
• High throughput: 60 samples per hour per instrument.
• Minimal operator training and simplified workflow suitable for on-site or field laboratories.
• Versatility across sample types without method redevelopment.

Future Trends and Potential Applications

Expansion of ambient ionization platforms and integration with high-speed mass spectrometers will further accelerate forensic screening. Potential developments include:

• Portable field deployable DPiMS systems for roadside or border control.
• Automated sample handling for full laboratory integration.
• Extension to broader drug panels and novel psychoactive substances.
• Coupling with machine-learning algorithms for real-time spectral interpretation.

Conclusion

This study demonstrates that DPiMS-8060 coupled with LCMS-8050 can deliver ultrafast, green, and reliable qualitative screening of critical illicit compounds in complex matrices. The approach reduces analysis time from 30 min to 1 min per sample, lowers solvent usage, and maintains sensitivity and specificity comparable to conventional GC/MS methods.

Reference

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