(A) Unified strategy for cannabis forensics : Integrating LC-MS/MS geographic profiling and validation of microfluidic On-site detection

다국어 초록 (Multilingual Abstract)

As global cannabis policies transition from uniform prohibition toward a fragmented landscape of legalization, forensic science has encountered a formidable dual challenge: the diversification of illicit supply networks and the technical constraints of conventional user screening. To address these emerging risks, this dissertation presents a comprehensive forensic architecture that bridges supply-side product intelligence with demand-side field monitoring.
On the supply side (Chapter 2), this research developed and implemented a high-resolution chemical fingerprinting methodology using Liquid Chromatography Tandem Mass Spectrometry (LC-MS/MS) to simultaneously quantify five key cannabinoids (Δ9-THC, Δ8-THC, CBD, CBN, and CBG). Through the systematic analysis of 63 commercial hemp seed oils from 10 countries, this study identified a "Variance-Discrimination Paradox," demonstrating that minor cannabinoids—specifically Δ8-THC and CBG—hold significantly higher discriminatory power for geographic attribution than major components. The 5-analyte integrated model attained a classification accuracy of 87.5%, providing sufficient analytical resolution to distinguish samples that remained ambiguous under traditional methods, such as Sample No. 49. Additionally, the profiling revealed a "Regulatory Paradox" by detecting psychoactive Δ8-THC within strictly regulated jurisdictions and established that visual luminance serves as an effective forensic triage marker for identifying illicit chemical processing.
On the demand side (Chapter 3), the study focused on the practical validation of a portable fluorescence-based microfluidic point-of-care testing (POCT) device designed for the rapid, semi-quantitative detection of THC-COOH in urine. By achieving a high-sensitivity cutoff of 20 ng/mL with 100% diagnostic accuracy, the device functions as a critical link between initial field screening and definitive laboratory confirmation. Forensic integrity is maintained through an automated digital logging system and Wi-Fi-enabled data transmission, which effectively secures the chain of custody.
Finally, this dissertation converges these two analytical pillars into an integrated intelligence framework. By correlating field-based demand signals with laboratory supply-chain profiling, this strategy establishes an operational pathway for law enforcement to transition from reactive seizures toward proactive, intelligence-led disruption of trafficking networks. This work defines the scientific and strategic parameters necessary for modernizing cannabis forensics amidst the increasing complexity of synthetic cannabinoid proliferation.
Chapters 2 and 3 of this dissertation are based on the author’s research currently in preparation for submission to an international journal and a previously published article in Sensors (Jung et al., 2025), respectively.

국문 초록 (Abstract)

글로벌 대마 정책이 전면적 금지에서 파편화된 합법화 체계로 전환됨에 따라,현대 법과학은 불법 공급망의 고도화와 기존 스크리닝 방식의 기술적 한계라는 중대한 이중과제에 직면해 있다. 본 연구는 이러한 치안 위협에 선제적으로 대응하고자, 공급측면의 제품 인텔리전스와 수요측면의 현장 모니터링 기술을 유기적으로 결합한 ‘통합 과학수사 전략’을 제안한다.
공급측면(제2장)에서는 LC-MS/MS 분석법을 활용하여 5종의 핵심 칸나비노이드(Δ9-THC, Δ8-THC, CBD, CBN, CBG)를 동시에 정량할 수 있는 고해상도 화학적 지문(Chemical Fingerprinting) 분석 기법을 확립하였다. 전 세계 10개국 63개 제품을 분석한 결과, 주요 성분 외에 미량의 Δ8-THC와 CBG를 분석 모델에 포함했을 때 지리적 변별력이 상승함을 확인하였으며, 이를 통해 소수 성분이 판별 성능을 주도한다는 ‘분산-변별력의 역설(Variance-Discrimination Paradox)’을 규명하였다. 본 연구에서 제시한 5종 성분 통합 모델은 87.5%의 분류 정확도를 나타냈으며, 특히 기존의 단일 성분 분석으로는 규명이 어려웠던 샘플(Sample No. 49 등)에 대해서도 유의미한 수준의 원산지 판별 성능을 확보하였다. 아울러 캐나다 등 엄격한 규제 시장 내 시료에서 합성과정의 부산물인 Δ8-THC를 검출하여 규제 맹점을 확인하였고, 오일의 휘도(luminance)가 단순 품질이 아닌 불법 가공 여부를 가려내는 핵심 법과학적 지표임을 실증하였다.
수요측면(제3장)에서는 소변 내 THC-COOH 성분을 신속히 검출하기 위해 휴대용 형광 마이크로유체 분석 시스템(POCT)의 현장 적용성을 검증하였다. 20 ng/mL의 고감도 검출 한계와 100%의 진단 정확도를 구현함으로써, 간이 스크리닝과 정밀 확인 분석 사이의 기술적 간극을 효과적으로 보완하였다. 또한 Wi-Fi 기반 자동 디지털 로깅 시스템을 도입하여 수사 데이터의 임의 조작 가능성을 원천 차단하고, 데이터의 신뢰도를 강화하였다.
결론적으로 본 논문은 개별적으로 운용되던 두 핵심 축을 하나의 지능형 정보 체계로 통합하였다. 현장의 수요 데이터와 실험실의 공급 프로파일링 정보를 연계함으로써, 법집행기관이 개별 단속 위주의 사후 대응에 벗어나 정보 기반의 선제적 공급망 차단 전략으로 전환할 수 있는 실효적 모델을 제시하였다. 본 연구는 복잡해지는 대마 시장과 합성 칸나비노이드의 확산에 대응하여 과학수사의 현대화를 위한 실질적인 과학적 토대를 제공할 것이다.
본 학위논문의 제2장과 제3장은 각각 저자가 국제 학술지에 투고 준비 중인 연구내용과 Sensors지에 게재한 논문(Jung et al., 2025)을 바탕으로 작성되었다.

목차 (Table of Contents)

• Chapter 1. Introduction 1
• 1.1. Background of the Study: A Global Paradigm Shift 1
• 1.2. Cannabis Sativa L. as a Forensic Subject 4
• 1.2.1. "Marijuana" vs. "Hemp": The Legal Definition 4
• 1.2.2. Forensic Significance of Key Cannabinoids and Metabolites 5
• 1.3. The Dual Challenges of Cannabis Forensics 6
• 1.3.1. The Supply-Side Challenge: The Rise of Semi-Synthetic Cannabinoids 6
• 1.3.2. The Demand-Side Challenge: Limitations of Current Screening 6
• 1.4. Aims of this Thesis: A Unified Strategy 7
• 1.5. Proposed Framework: A Unified Forensic Strategy 7
• Chapter 2. Chemical Fingerprinting of Cannabis Products: A Proof-of-Concept of Supply Chain Tracking 10
• 2.1. Introduction 10
• 2.1.1. The Paradigm Shift in Cannabis Forensics: From User to Supply Chain 10
• 2.1.2. The Mechanism of "Chemical Evolution" and Its Risks 13
• 2.1.3. Chemical Fingerprinting as Forensic Intelligence 13
• 2.1.4. Research Objectives and Scope: A Proof-of-Concept 14
• 2.2. Materials and Methods 16
• 2.2.1. Sample Collection 16
• 2.2.2. Selection Rationale for Target Analytes 16
• 2.2.3. Chemical and Reagents 17
• 2.2.4. Preparation of Calibration Standards and Quality Control Samples 17
• 2.2.5. Sample Preparation 18
• 2.2.6. LC-MS/MS Instrumentation and Conditions 18
• 2.2.7. Method Validation 19
• 2.2.8. Color Measurement by Digital Image Analysis 20
• 2.2.9. Statistical and Chemometric Analysis 21
• 2.3. Results 25
• 2.3.1. Overview of Cannabinoid Quantification and Prevalence 25
• 2.3.2. Enhancement of Geographic Discrimination via 5-Cannabinoid Profiling 27
• 2.3.3. Validation of Discriminatory Power on Key Geographic Regions 29
• 2.3.4. Chemotype Differentiation using Cannabinoid Ratios 31
• 2.3.5. Uncovering the "Regulatory Paradox": Prevalence of Δ8-THC 33
• 2.3.6. Identification and Characterization of a Unique Outlier: Sample 29 33
• 2.3.7. Association between Oil Luminance and Chemical Profiles 36
• 2.4. Discussion: Implications for Forensic Intelligence 40
• 2.4.1. Comprehensive Cannabinoid Profiling as a Practical Forensic Tool 40
• 2.4.2. Visual Metrics as a Triage Indicator for Chemical Processing 41
• 2.4.3. Forensic Scalability: Linking Crime Scene via Manufacturer-Specific Recipes 42
• 2.4.4. From Exploratory Analysis to Probabilistic Attribution: The Need for Sample Expansion 43
• 2.5. Summary 45
• Chapter 3. Validation of a Microfluidic On-Site Device for Rapid and Semi-Quantitative THC-COOH Detection 47
• 3.1. Introduction 47
• 3.2. Materials and Methods 50
• 3.2.1. Fabrication and Surface Modification of the Microfluidic Platform 50
• 3.2.2. Competitive Assay Design and Bioconjugation 52
• 3.2.3. Signal Acquisition and COI Calculation 55
• 3.2.4. Analytical Performance and Reliability Assessment (LDT Protocol) 55
• 3.2.5. Authentic Forensic Sample Collection and Cutoff Rationale 56
• 3.2.6. Quantitative Confirmation by LC-MS/MS 56
• 3.2.7. Correlation Analysis: Microfluidic Device vs. LC-MS/MS 59
• 3.3. Results 60
• 3.3.1. Reliability and Precision Evaluation (LDT Protocol Results) 60
• 3.3.2. Validation of the LC-MS/MS Reference Method 64
• 3.3.3. Field Applicability Validation with Authentic Forensic Samples 68
• 3.3.4. Correlation between Microfluidic COI and LC-MS/MS Quantification 70
• 3.3.5. User Interface and Digital Data Management 71
• 3.4. Discussion 73
• 3.4.1. Realization of High-Sensitivity Semi-Quantification 73
• 3.4.2. Validation of Total Metabolite Detection for Enhanced Reliability 73
• 3.4.3. Ensuring Data Integrity for Forensic Evidence 74
• 3.4.4. Comparative Analysis of Existing Screening Methods 74
• 3.4.5. Limitations and Future Perspectives in Field Deployment 76
• 3.5. Summary 78
• Chapter 4. General Discussion: A Unified Strategy for Cannabis Forensics 79
• 4.1. Bridging the Demand-Side and Supply-Side Solutions 79
• 4.2. The Feedback Loop: From Detection to Intelligence 80
• 4.2.1. Tactical Intelligence (Immediate Response) 80
• 4.2.2. Operational Intelligence (Regional Pattern Recognition) 80
• 4.2.3. Strategic Intelligence (Network Mapping) 81
• 4.2.4. Crucial Innovation 81
• 4.3. Forensic Scalability: Linking Crime Scenes via Manufacturer- Specific Recipes 82
• 4.3.1. Why Illicit Products Present Superior Forensic Opportunities 82
• 4.3.2. Manufacturer Attribution and Linkage Analysis 82
• 4.3.3. Rapid Triage and Resource Allocation 85
• 4.3.4. The Jelly Case: From Public Health Threat to Forensic Intelligence 85
• 4.4. Forensic Robustness: Standardization and Legal Admissibility 86
• 4.5. Limitations and Future Directions 87
• 4.5.1. Limitations of This Study 87
• 4.5.2. Future Implementation 87
• Chapter 5. Conclusions and Future Work 88
• 5.1. Conclusions 88
• 5.1.1. Supply-Side Achievement 88
• 5.1.2. Demand-side performance 89
• 5.1.3. Integrated Achievement 89
• 5.1.4. Regulatory and Public Health Significance 90
• 5.1.5. Synthesis 90
• 5.1.6. Forensic Robustness and Admissibility 90
• 5.2. Future Work 91
• References 93
• Appendix 101
• 국문초록 114